This document provides summaries of key topics related to systems and models, ecosystems, and human population dynamics.
1) It defines systems, models, laws of thermodynamics, and equilibrium concepts. It also discusses feedback, transfers and transformations of matter and energy.
2) It defines ecosystem components and processes like biotic and abiotic factors, trophic levels, and ecological pyramids. It also summarizes different biomes and their characteristics.
3) It discusses human population dynamics concepts like exponential and logistic growth models, r/K selection strategies, and factors affecting population size. It also summarizes Malthusian and Boserup theories on population growth and food supply.
This document summarizes key concepts from topics about systems and models, ecosystems, and human population and resource use covered in the IB ESS exam. It defines important terms like open and closed systems, feedback, and transfers and transformations of matter and energy. It also describes different biomes and their characteristics, ecosystem structure including food chains and trophic levels, and population interactions such as competition, predation, and succession. Finally, it discusses human population dynamics and factors that can limit exponential growth.
The document provides information on several topics related to ecosystems and human populations:
1. It defines key terms related to systems, models, and thermodynamics including open/closed/isolated systems, laws of thermodynamics, and equilibrium.
2. It outlines definitions and concepts for ecosystems like biotic/abiotic factors, biomes, trophic levels, ecological pyramids, population interactions, and succession.
3. It discusses human population dynamics including exponential growth and density-dependent limiting factors that lead to population stability through negative feedback mechanisms.
This document provides a comprehensive list of case studies and examples for the International Baccalaureate Environmental Systems and Societies (IB ESS) exam, organized by topic. It includes specific examples of systems, ecosystems, populations, resources, pollution events, climate change impacts, and contrasting environmental value systems that students should know for the exam. While not a complete list, it covers many key topics and concepts that may be assessed.
This document contains 10 essay questions related to environmental systems and societies. The first question asks the student to describe a method for measuring changes in abiotic components in a named ecosystem affected by human activity. The second question asks the student to describe ecocentric and technocentric responses to global warming and justify which may be more effective. The third question asks the student to outline the environmental impact of two named food production systems.
This document outlines concepts related to systems thinking from pages 69-90 of the IB ESS Course Companion. It defines key terms like systems, open and closed systems, feedback loops, and equilibria. It also explains how systems can be analyzed on different scales from cells to biomes to the whole Earth. The document provides examples and details about how systems thinking is applied in environmental science.
How to Write ESS Essay Questions in Paper 2-First Exam 2017GURU CHARAN KUMAR
This document provides information about essay questions on the IB ESS exam. It notes that:
- Paper 2 Section B contains two essay questions worth 20 marks each from a choice of four.
- Each essay question has three parts (A, B, and C) with varying point values.
- Part C is marked based on mark bands and requires evaluation, synthesis, and justification.
- The document also outlines the assessment objectives for ESS, including knowledge, application, evaluation, and engagement with environmental issues. It provides examples of key command terms used in ESS essay questions like define, describe, and distinguish.
This document contains sample essay questions and responses about ecosystems and human impacts on the environment.
The first question asks to describe methods to record changes in an ecosystem like the Alpine Pine Forest from human activities, such as using sampling methods to measure species abundance and diversity over time.
The second question explains how human activity has increased nitrogen in ecosystems through fertilizer use and fossil fuel combustion, and the impacts like acid rain, soil acidification, and eutrophication.
The third question evaluates the role of Environmental Impact Assessments in different societies, noting they can empower communities but be biased if developers fund them, and may not be affordable or prioritized in all contexts.
This document summarizes key concepts from topics about systems and models, ecosystems, and human population and resource use covered in the IB ESS exam. It defines important terms like open and closed systems, feedback, and transfers and transformations of matter and energy. It also describes different biomes and their characteristics, ecosystem structure including food chains and trophic levels, and population interactions such as competition, predation, and succession. Finally, it discusses human population dynamics and factors that can limit exponential growth.
The document provides information on several topics related to ecosystems and human populations:
1. It defines key terms related to systems, models, and thermodynamics including open/closed/isolated systems, laws of thermodynamics, and equilibrium.
2. It outlines definitions and concepts for ecosystems like biotic/abiotic factors, biomes, trophic levels, ecological pyramids, population interactions, and succession.
3. It discusses human population dynamics including exponential growth and density-dependent limiting factors that lead to population stability through negative feedback mechanisms.
This document provides a comprehensive list of case studies and examples for the International Baccalaureate Environmental Systems and Societies (IB ESS) exam, organized by topic. It includes specific examples of systems, ecosystems, populations, resources, pollution events, climate change impacts, and contrasting environmental value systems that students should know for the exam. While not a complete list, it covers many key topics and concepts that may be assessed.
This document contains 10 essay questions related to environmental systems and societies. The first question asks the student to describe a method for measuring changes in abiotic components in a named ecosystem affected by human activity. The second question asks the student to describe ecocentric and technocentric responses to global warming and justify which may be more effective. The third question asks the student to outline the environmental impact of two named food production systems.
This document outlines concepts related to systems thinking from pages 69-90 of the IB ESS Course Companion. It defines key terms like systems, open and closed systems, feedback loops, and equilibria. It also explains how systems can be analyzed on different scales from cells to biomes to the whole Earth. The document provides examples and details about how systems thinking is applied in environmental science.
How to Write ESS Essay Questions in Paper 2-First Exam 2017GURU CHARAN KUMAR
This document provides information about essay questions on the IB ESS exam. It notes that:
- Paper 2 Section B contains two essay questions worth 20 marks each from a choice of four.
- Each essay question has three parts (A, B, and C) with varying point values.
- Part C is marked based on mark bands and requires evaluation, synthesis, and justification.
- The document also outlines the assessment objectives for ESS, including knowledge, application, evaluation, and engagement with environmental issues. It provides examples of key command terms used in ESS essay questions like define, describe, and distinguish.
This document contains sample essay questions and responses about ecosystems and human impacts on the environment.
The first question asks to describe methods to record changes in an ecosystem like the Alpine Pine Forest from human activities, such as using sampling methods to measure species abundance and diversity over time.
The second question explains how human activity has increased nitrogen in ecosystems through fertilizer use and fossil fuel combustion, and the impacts like acid rain, soil acidification, and eutrophication.
The third question evaluates the role of Environmental Impact Assessments in different societies, noting they can empower communities but be biased if developers fund them, and may not be affordable or prioritized in all contexts.
Here are some key points to consider in your response:
1. The range of energy resources includes renewable (solar, hydroelectric, geothermal, biomass, tidal, wave) and non-renewable (coal, gas, oil, nuclear).
2. Advantages and disadvantages of resources will vary but may include factors like environmental impacts, costs, existing infrastructure, resource availability, and public perception.
3. Choice of resources is influenced by factors such as economic development, historical dependence, infrastructure, public attitudes, policy, energy demands, and environmental concerns. MEDCs tend to rely more on non-renewables due to higher energy demands while LEDCs traditionally use more renewable resources. Transitioning energy systems requires overcoming
This document defines biomes and provides details on the distribution, structure, and relative productivity of several major biomes, including tropical rainforests, deserts, tundra, temperate deciduous forests, prairies, savannas, chaparral, coral reefs, estuaries, lakes and rivers. It lists recommended websites for further information on biomes and their global distribution. Key details are provided for each biome.
Understandings:
Most species occupy different trophic levels in multiple food chains
A food web shows all the possible food chains in a community
The percentage of ingested energy converted to biomass is dependent upon the respiration rate
The type of stable ecosystem that will emerge in an area is predictable based on climate
In closed ecosystems energy but not matter is exchanged with the surroundings
Disturbance influxes the structure and rate of change within ecosystems
Applications:
Conversion ratio in sustainable food production practices
Consideration of one example how humans interfere with nutrient cycling
Skills:
Comparison of pyramids of energy from different ecosystems
Analysis of a climograph showing the relationship between temperature, rainfall and the type of ecosystem
Construction of Gersmehl diagrams to show the inter-relationships between nutrient stores and flows between taiga, desert, and tropical rainforest.
Analysis of data showing a primary succession
An investigation into the effect of an environmental disturbance on an ecosystem
Natural capital refers to the resources available for human exploitation including renewable, replenishable, and non-renewable resources found in the biosphere, lithosphere, and atmosphere. Renewable resources like timber can be replaced through natural processes like photosynthesis, while replenishable resources like solar energy are continually replaced through abiotic processes. Non-renewable resources like fossil fuels cannot be naturally replaced within human timescales. Sustainable development aims to meet current needs without compromising future generations by limiting use of non-renewables and switching to renewables. However, there is debate around balancing environmental, economic, and social factors.
1. Biomes are determined by factors like temperature, rainfall, and sunlight which affect photosynthesis and net primary productivity. Different biomes like tropical rainforests, savannas, and tundra support characteristic plant life adapted to their climate.
2. Succession over time and zonation over environmental gradients cause changes in plant communities. Early successional "pioneer" species establish first, followed by later successional species that outcompete pioneers. Eventually a stable "climax" community develops.
3. Human impacts like deforestation and grazing can interrupt succession, maintaining early successional "plagioclimax" communities
This document discusses biodiversity, including its definition, components, and methods for measuring it. Biodiversity refers to the variety of species, habitats, and genetic diversity in an area. It can be measured by species diversity, habitat diversity, and genetic diversity. Methods for measuring biodiversity include counting species richness, calculating Simpson's Diversity Index using population data from quadrats, mark-recapture studies using the Lincoln Index, and chemical fogging to sample canopy insects. Global patterns of biodiversity are also addressed.
This document discusses energy flow and matter cycling in ecosystems. It explains that only a small portion (around 0.06%) of the sun's energy is captured by producers through photosynthesis. Primary productivity is the gain in biomass by producers, while secondary productivity is the gain by heterotrophs. Gross productivity does not account for energy losses from respiration, while net productivity does. Formulas are provided to calculate net primary productivity (NPP) and net secondary productivity (NSP). The carbon, nitrogen, and water cycles are also summarized. Maximum NPP values are listed for different biomes.
This document discusses water pollution and eutrophication. It defines different types of water pollutants and methods for monitoring pollution, including direct chemical measurements and indirect biological indicators like BOD and indicator species. Eutrophication occurs when a water body receives too many nutrients, causing algal blooms that reduce oxygen levels. Symptoms include decreased biodiversity and dissolved oxygen. Management strategies include reducing nutrient inputs from fertilizers and sewage, removing pollutants from water, and regulations on industries and public behaviors.
1. The document discusses various types of pollution caused by human activities and their impacts. It defines pollution and describes different forms such as air pollution, light pollution, and point source versus non-point source pollution.
2. DDT is used as a case study to illustrate the conflicts between the utility of a substance and its environmental impacts. While DDT was widely used for malaria control, it bioaccumulated in ecosystems and contributed to thinning eggshells and declines in bird populations like bald eagles.
3. The costs of pollution are extensive and include impacts on human health, natural systems, and economic losses. Air pollution alone results in over $200 billion in lost income annually due to premature deaths.
Communities and ecosystems are defined. A community is a group of populations living and interacting in a common habitat, while an ecosystem includes both the community and its physical environment. Photosynthesis and respiration play key roles in energy flow, with photosynthesis converting light energy to chemical energy in producers and respiration releasing energy through the breakdown of organic matter. These processes can be represented by word equations and involve inputs, outputs and transformations of energy and matter.
Communities can be described and compared through diversity indices which take into account the number of species and their distribution. Low diversity indices could indicate pollution, eutrophication, or recent colonization. Quantifying biodiversity is important for conservation efforts to identify and protect high biodiversity areas. Assessing changes in biodiversity over time helps evaluate human impacts on communities.
This document contains an answer scheme for an end of semester test in Grade 11. It provides the questions asked in the test and the marking scheme for student responses. The test covered topics related to population ecology, including predator-prey interactions, food webs, methods for estimating population sizes, biodiversity indices, and energy flow through ecosystems. The summary provides the essential information while being concise.
Getting to the Core of Paper 2 - ESS.pdfNigel Gardner
How important are the 9 mark questions in IB Diploma Environmental Systems and Societies?
Where do those questions come from?
How do you teach to answer those questions?
This document provides instructions and questions for an end of semester test in Environmental Systems and Societies. It includes:
- Instructions directing candidates to answer all questions in Section A in the provided spaces.
- Section A contains 6 multi-part questions related to population dynamics, food webs, feedback mechanisms, and thermodynamics. Candidates are asked to interpret graphs, identify time lags, predict impacts, and explain concepts.
- The test has a maximum mark of 80 and is 1 hour and 30 minutes in duration. It is for grade 11 students and covers the SL (Standard Level) curriculum.
Ess topic 1 foundations of environmental systems and societies(first exam 2017)GURU CHARAN KUMAR
Topic 1: Foundations of environmental systems and societies (16 hours)
Big questions: This topic may be particularly appropriate for considering big questions A, C, D and E.
Sub-topic 1.1: Environmental value systems
Significant ideas:
• Historical events, among other influences, affect the development of environmental value systems (EVSs) and environmental movements.
• There is a wide spectrum of EVSs, each with its own premises and implications.
Knowledge and understanding:
• Significant historical influences on the development of the environmental
movement have come from literature, the media, major environmental disasters,
international agreements and technological developments.
• An EVS is a worldview or paradigm that shapes the way an individual, or group
of people, perceives and evaluates environmental issues, influenced by cultural,
religious, economic and socio-political contexts.
• An EVS might be considered as a system in the sense that it may be influenced
by education, experience, culture and media (inputs), and involves a set of
interrelated premises, values and arguments that can generate consistent
decisions and evaluations (outputs).
• There is a spectrum of EVSs, from ecocentric through anthropocentric to
technocentric value systems.
• An ecocentric viewpoint integrates social, spiritual and environmental
dimensions into a holistic ideal. It puts ecology and nature as central to humanity
and emphasizes a less materialistic approach to life with greater self-sufficiency
of societies. An ecocentric viewpoint prioritizes biorights, emphasizes the
importance of education and encourages self-restraint in human behaviour.
• An anthropocentric viewpoint argues that humans must sustainably manage the
global system. This might be through the use of taxes, environmental regulation
and legislation. Debate would be encouraged to reach a consensual, pragmatic
approach to solving environmental problems.
• A
This document discusses climate change mitigation and adaptation strategies. It defines mitigation as actions to reduce or stabilize greenhouse gas emissions. Methods of mitigation mentioned include reducing energy consumption, emissions from agriculture and deforestation, switching to renewable energies, carbon sequestration, and geoengineering techniques. Policy strategies are outlined at national and individual levels, including limiting carbon emissions and increasing renewable energy and forestation. The Kyoto Protocol is summarized as an international agreement for countries to reduce greenhouse gases through emissions trading and carbon offsetting via forestation. It was extended until 2020 and strengthened by the Paris Accords.
Pollution is defined as the addition of substances that harm the environment at a rate faster than it can be rendered harmless. Pollution can be natural or anthropogenic and come from point sources like factories that can be mapped, or non-point sources like vehicle emissions that are more dispersed. Major sources of pollution include sewage, mining, agriculture, industry, and waste. Pollution can seriously harm public health, water quality, soil quality, and lead to death in some cases. DDT was a widely used pesticide that was banned in many countries after being found to cause harm by weakening bird egg shells and linking to birth defects and cancer in other animals.
This document discusses access to freshwater around the world. Only a small percentage of Earth's total water is freshwater, and its distribution is inequitable with many less economically developed countries lacking access. The turnover time, or time it takes for water to cycle from one part of the hydrologic cycle to another, varies significantly from 10,000 years for ice caps to just 12 days for rivers and the atmosphere. Increasing water usage in many areas is threatening sustainability as populations rise without adequate conservation efforts. The case study of Mexico City illustrates some of these challenges as groundwater is overexploited and wastewater is increasingly reused to try and meet the needs of the large population.
Here are some key points to consider in your response:
1. The range of energy resources includes renewable (solar, hydroelectric, geothermal, biomass, tidal, wave) and non-renewable (coal, gas, oil, nuclear).
2. Advantages and disadvantages of resources will vary but may include factors like environmental impacts, costs, existing infrastructure, resource availability, and public perception.
3. Choice of resources is influenced by factors such as economic development, historical dependence, infrastructure, public attitudes, policy, energy demands, and environmental concerns. MEDCs tend to rely more on non-renewables due to higher energy demands while LEDCs traditionally use more renewable resources. Transitioning energy systems requires overcoming
This document defines biomes and provides details on the distribution, structure, and relative productivity of several major biomes, including tropical rainforests, deserts, tundra, temperate deciduous forests, prairies, savannas, chaparral, coral reefs, estuaries, lakes and rivers. It lists recommended websites for further information on biomes and their global distribution. Key details are provided for each biome.
Understandings:
Most species occupy different trophic levels in multiple food chains
A food web shows all the possible food chains in a community
The percentage of ingested energy converted to biomass is dependent upon the respiration rate
The type of stable ecosystem that will emerge in an area is predictable based on climate
In closed ecosystems energy but not matter is exchanged with the surroundings
Disturbance influxes the structure and rate of change within ecosystems
Applications:
Conversion ratio in sustainable food production practices
Consideration of one example how humans interfere with nutrient cycling
Skills:
Comparison of pyramids of energy from different ecosystems
Analysis of a climograph showing the relationship between temperature, rainfall and the type of ecosystem
Construction of Gersmehl diagrams to show the inter-relationships between nutrient stores and flows between taiga, desert, and tropical rainforest.
Analysis of data showing a primary succession
An investigation into the effect of an environmental disturbance on an ecosystem
Natural capital refers to the resources available for human exploitation including renewable, replenishable, and non-renewable resources found in the biosphere, lithosphere, and atmosphere. Renewable resources like timber can be replaced through natural processes like photosynthesis, while replenishable resources like solar energy are continually replaced through abiotic processes. Non-renewable resources like fossil fuels cannot be naturally replaced within human timescales. Sustainable development aims to meet current needs without compromising future generations by limiting use of non-renewables and switching to renewables. However, there is debate around balancing environmental, economic, and social factors.
1. Biomes are determined by factors like temperature, rainfall, and sunlight which affect photosynthesis and net primary productivity. Different biomes like tropical rainforests, savannas, and tundra support characteristic plant life adapted to their climate.
2. Succession over time and zonation over environmental gradients cause changes in plant communities. Early successional "pioneer" species establish first, followed by later successional species that outcompete pioneers. Eventually a stable "climax" community develops.
3. Human impacts like deforestation and grazing can interrupt succession, maintaining early successional "plagioclimax" communities
This document discusses biodiversity, including its definition, components, and methods for measuring it. Biodiversity refers to the variety of species, habitats, and genetic diversity in an area. It can be measured by species diversity, habitat diversity, and genetic diversity. Methods for measuring biodiversity include counting species richness, calculating Simpson's Diversity Index using population data from quadrats, mark-recapture studies using the Lincoln Index, and chemical fogging to sample canopy insects. Global patterns of biodiversity are also addressed.
This document discusses energy flow and matter cycling in ecosystems. It explains that only a small portion (around 0.06%) of the sun's energy is captured by producers through photosynthesis. Primary productivity is the gain in biomass by producers, while secondary productivity is the gain by heterotrophs. Gross productivity does not account for energy losses from respiration, while net productivity does. Formulas are provided to calculate net primary productivity (NPP) and net secondary productivity (NSP). The carbon, nitrogen, and water cycles are also summarized. Maximum NPP values are listed for different biomes.
This document discusses water pollution and eutrophication. It defines different types of water pollutants and methods for monitoring pollution, including direct chemical measurements and indirect biological indicators like BOD and indicator species. Eutrophication occurs when a water body receives too many nutrients, causing algal blooms that reduce oxygen levels. Symptoms include decreased biodiversity and dissolved oxygen. Management strategies include reducing nutrient inputs from fertilizers and sewage, removing pollutants from water, and regulations on industries and public behaviors.
1. The document discusses various types of pollution caused by human activities and their impacts. It defines pollution and describes different forms such as air pollution, light pollution, and point source versus non-point source pollution.
2. DDT is used as a case study to illustrate the conflicts between the utility of a substance and its environmental impacts. While DDT was widely used for malaria control, it bioaccumulated in ecosystems and contributed to thinning eggshells and declines in bird populations like bald eagles.
3. The costs of pollution are extensive and include impacts on human health, natural systems, and economic losses. Air pollution alone results in over $200 billion in lost income annually due to premature deaths.
Communities and ecosystems are defined. A community is a group of populations living and interacting in a common habitat, while an ecosystem includes both the community and its physical environment. Photosynthesis and respiration play key roles in energy flow, with photosynthesis converting light energy to chemical energy in producers and respiration releasing energy through the breakdown of organic matter. These processes can be represented by word equations and involve inputs, outputs and transformations of energy and matter.
Communities can be described and compared through diversity indices which take into account the number of species and their distribution. Low diversity indices could indicate pollution, eutrophication, or recent colonization. Quantifying biodiversity is important for conservation efforts to identify and protect high biodiversity areas. Assessing changes in biodiversity over time helps evaluate human impacts on communities.
This document contains an answer scheme for an end of semester test in Grade 11. It provides the questions asked in the test and the marking scheme for student responses. The test covered topics related to population ecology, including predator-prey interactions, food webs, methods for estimating population sizes, biodiversity indices, and energy flow through ecosystems. The summary provides the essential information while being concise.
Getting to the Core of Paper 2 - ESS.pdfNigel Gardner
How important are the 9 mark questions in IB Diploma Environmental Systems and Societies?
Where do those questions come from?
How do you teach to answer those questions?
This document provides instructions and questions for an end of semester test in Environmental Systems and Societies. It includes:
- Instructions directing candidates to answer all questions in Section A in the provided spaces.
- Section A contains 6 multi-part questions related to population dynamics, food webs, feedback mechanisms, and thermodynamics. Candidates are asked to interpret graphs, identify time lags, predict impacts, and explain concepts.
- The test has a maximum mark of 80 and is 1 hour and 30 minutes in duration. It is for grade 11 students and covers the SL (Standard Level) curriculum.
Ess topic 1 foundations of environmental systems and societies(first exam 2017)GURU CHARAN KUMAR
Topic 1: Foundations of environmental systems and societies (16 hours)
Big questions: This topic may be particularly appropriate for considering big questions A, C, D and E.
Sub-topic 1.1: Environmental value systems
Significant ideas:
• Historical events, among other influences, affect the development of environmental value systems (EVSs) and environmental movements.
• There is a wide spectrum of EVSs, each with its own premises and implications.
Knowledge and understanding:
• Significant historical influences on the development of the environmental
movement have come from literature, the media, major environmental disasters,
international agreements and technological developments.
• An EVS is a worldview or paradigm that shapes the way an individual, or group
of people, perceives and evaluates environmental issues, influenced by cultural,
religious, economic and socio-political contexts.
• An EVS might be considered as a system in the sense that it may be influenced
by education, experience, culture and media (inputs), and involves a set of
interrelated premises, values and arguments that can generate consistent
decisions and evaluations (outputs).
• There is a spectrum of EVSs, from ecocentric through anthropocentric to
technocentric value systems.
• An ecocentric viewpoint integrates social, spiritual and environmental
dimensions into a holistic ideal. It puts ecology and nature as central to humanity
and emphasizes a less materialistic approach to life with greater self-sufficiency
of societies. An ecocentric viewpoint prioritizes biorights, emphasizes the
importance of education and encourages self-restraint in human behaviour.
• An anthropocentric viewpoint argues that humans must sustainably manage the
global system. This might be through the use of taxes, environmental regulation
and legislation. Debate would be encouraged to reach a consensual, pragmatic
approach to solving environmental problems.
• A
This document discusses climate change mitigation and adaptation strategies. It defines mitigation as actions to reduce or stabilize greenhouse gas emissions. Methods of mitigation mentioned include reducing energy consumption, emissions from agriculture and deforestation, switching to renewable energies, carbon sequestration, and geoengineering techniques. Policy strategies are outlined at national and individual levels, including limiting carbon emissions and increasing renewable energy and forestation. The Kyoto Protocol is summarized as an international agreement for countries to reduce greenhouse gases through emissions trading and carbon offsetting via forestation. It was extended until 2020 and strengthened by the Paris Accords.
Pollution is defined as the addition of substances that harm the environment at a rate faster than it can be rendered harmless. Pollution can be natural or anthropogenic and come from point sources like factories that can be mapped, or non-point sources like vehicle emissions that are more dispersed. Major sources of pollution include sewage, mining, agriculture, industry, and waste. Pollution can seriously harm public health, water quality, soil quality, and lead to death in some cases. DDT was a widely used pesticide that was banned in many countries after being found to cause harm by weakening bird egg shells and linking to birth defects and cancer in other animals.
This document discusses access to freshwater around the world. Only a small percentage of Earth's total water is freshwater, and its distribution is inequitable with many less economically developed countries lacking access. The turnover time, or time it takes for water to cycle from one part of the hydrologic cycle to another, varies significantly from 10,000 years for ice caps to just 12 days for rivers and the atmosphere. Increasing water usage in many areas is threatening sustainability as populations rise without adequate conservation efforts. The case study of Mexico City illustrates some of these challenges as groundwater is overexploited and wastewater is increasingly reused to try and meet the needs of the large population.
This document discusses key concepts in environmental systems and societies, including:
1. Ecosystems can range from small self-contained communities to the entire biosphere of the planet. Biomes are large open ecosystems that span stable climates.
2. The laws of thermodynamics state that energy is conserved but tends towards disorder, so systems seek equilibrium. There are several types of equilibrium including static, steady state, stable, and unstable.
3. Feedback mechanisms can be positive or negative, with negative feedback restoring equilibrium and positive feedback driving a system to a new state. Examples of feedback in maintaining human body temperature are provided.
This document discusses water systems and the global water cycle. It describes the three main types of ecosystems - marine, freshwater, and terrestrial - and notes that most global ecosystems are water-based. It then explains the key components of the water cycle, including storages like oceans, groundwater, and glaciers, and flows like evaporation, precipitation, melting, and streams. It notes that the ocean conveyor belt and Gulf Stream play an important role in distributing heat and affecting climate. Finally, it discusses some human impacts like unsustainable water use, changes to flows and storages, and water pollution.
The document describes the rules and structure of a quiz competition involving 6 topics: physics, chemistry, biology, computer science, environmental science, and sports science. It explains that there will be 4 rounds, teams can earn 10-15 points per correct answer depending on the round, and there is a time limit for answering. It provides examples of sample questions and clues that could be asked.
The document provides definitions and concepts related to ecosystems, including:
1. Definitions of ecosystems and their structure, including biomass and dead organic matter.
2. Functions of ecosystems, including energy and nutrient flows through photosynthesis, trophic levels, and nutrient recycling.
3. Plant succession and how plant communities change over time from pioneer to climax species in response to changing environmental conditions.
Aquatic food production systems provide many food sources for human consumption including algae, fish, shellfish, and other organisms. These systems face sustainability challenges due to overexploitation from fishing and environmental impacts from aquaculture. Effective management strategies like catch limits, marine protected areas, and regulating farm practices are needed to support long-term viability of aquatic food resources.
The document discusses the causes and impacts of climate change. It explains that greenhouse gases like carbon dioxide, methane, and water vapor naturally trap heat in the atmosphere and maintain a habitable temperature on Earth. However, human activities like burning fossil fuels and deforestation have increased the concentration of greenhouse gases, raising global temperatures beyond natural levels and threatening severe environmental and social consequences. While debates continue over the scale and solutions, most experts agree that reducing emissions through renewable energy and carbon pricing can mitigate the risks of climate change.
1) Food production systems range from subsistence farming in LEDCs to intensive commercial farming in MEDCs. LEDCs often focus on subsistence farming for local consumption while MEDCs protect domestic agriculture through import tariffs.
2) Climate change is expected to negatively impact food production more in LEDCs through increased drought, flooding and heat waves. This could destroy crops over large areas.
3) Sustainable agriculture practices include reducing meat consumption, increasing organic and local foods, improving food labels, and planting buffer zones to reduce nutrient runoff.
This document discusses soils and soil systems. It describes soils as the interface between the atmosphere, lithosphere, biosphere and hydrosphere. Soils are comprised of regolith, organic matter, air and water. Soils exist in solid, liquid and gas states and take a long time to develop, making them a non-renewable resource. The document outlines the inputs, outputs, storages and transformations that occur within soil systems and describes the role of soils in terrestrial food production systems and societies.
The document discusses two case studies of soil degradation: the Dust Bowl of the 1930s in the US and the drying of the Aral Sea in Central Asia by the Soviet Union. Both events were caused by unsustainable farming and water use practices that removed protective vegetation from the soil, leading to widespread dust storms and desertification. The document also discusses the global issue of soil degradation, its causes like erosion, pollution, overgrazing and mismanaged farmland, and techniques to conserve soil like reducing erosion, managing nutrients, limiting compaction, and preventing overgrazing.
The document discusses systems and models. It defines a system as consisting of storages, flows, processes, and feedback mechanisms. A model is defined as a simplified version of reality that can be used to see how a system works and predict how it will respond to change, though models involve some loss of accuracy. The document also discusses open, closed, and isolated ecosystems and asks questions about representing systems using diagrams and whether certain types of ecosystems truly exist.
Environmental value systems are sets of paradigms that shape how individuals and societies perceive environmental issues. They are influenced by cultural, religious, economic, and development factors and function similarly to other systems by having inputs, outputs, processing, and feedback loops based on the flow of information. Different environmental value systems can come into conflict over issues. The main categories are ecocentric (nature-centered), technocentric (technology-centered), and anthropocentric (human-centered). These differing philosophies can affect political decisions on topics like water exploitation, climate change, fossil fuel use, and ecological footprints.
Ecosystem: for students studying environmental BiologyGauri Haval
This document provides an overview of ecosystems. It defines an ecosystem as any system composed of physical, chemical, and biological processes within a space-time unit of any magnitude. Ecosystems can be divided into biomes characterized by climate, landscape, or vegetation. Biomes contain various habitats and are home to populations, communities, and food webs. Energy flows through ecosystems via food chains and pyramids. The document also discusses different types of ecosystems such as forests, tundra, and rainforests, and how they are structured and function.
Ecology is the study of relationships between organisms and their environment. It is organized into levels from smallest (organism) to largest (biosphere). Energy flows through ecosystems via food chains and webs from producers to various consumer trophic levels. Matter recycles through biogeochemical cycles like carbon, nitrogen, phosphorus and water. Populations grow according to exponential or logistic models depending on resources and limiting factors. Communities involve interactions like competition, predation, and symbiosis that structure species niches.
This biology lesson plan discusses ecosystems and communities. It begins with defining key terms like gross primary production, net primary production, and biomass. It then explains how to construct models of ecosystems, like pyramids of energy, and compare different ecosystems. The lesson also covers topics like trophic levels, nutrient cycling, succession, and biomes. Examples and calculations are provided to illustrate important concepts. Students will analyze models and examples from resources provided by the teacher.
The document provides information about ecosystems and ecology. It begins with definitions of ecosystems as self-regulating groups of interacting species and their environment, and ecology as the study of organism interactions and relationships. It then describes the key components and structure of ecosystems, including abiotic (physical and chemical) and biotic factors. Biotic components include producers (photoautotrophs and chemoautotrophs), consumers (herbivores, carnivores, omnivores, detritivores), and decomposers. The document also discusses energy flow and trophic levels in food chains and food webs in ecosystems.
The document discusses key concepts related to ecosystems and their functioning. It begins by defining an ecosystem as the functional unit where living organisms interact with each other and their physical environment. It then discusses various ecosystem components like species composition, stratification, productivity, decomposition, energy flow and nutrient cycling. The document further explains concepts like trophic levels, food chains, food webs and ecological pyramids. It also covers ecological succession and biogeochemical cycles of nitrogen and phosphorus.
1. The document provides information about various types of ecosystems including terrestrial, aquatic, forest, grassland, desert, pond, lake, marine and ocean ecosystems.
2. It describes the key components of an ecosystem as biotic factors (living organisms) and abiotic factors (non-living physical components).
3. Energy flows through ecosystems via food chains and food webs with plants at the base converting solar energy to chemical energy which is then transferred between trophic levels.
The document discusses environmental science and engineering topics that will be covered in a course. It includes 5 units: Environment, Ecosystem and Biodiversity; Environmental Pollution; Natural Resources; Social Issues and the Environment; and Human Population and the Environment. The course will examine relationships between humans and the environment and how to develop environmental protection plans. It will provide awareness of problems and the need for conservation to identify and solve issues.
This document provides an overview of ecology and population ecology. It defines ecology as the study of interactions between organisms and their environment. It describes different levels of ecological organization from cells to biomes. It explains abiotic and biotic factors in ecosystems and how organisms are adapted to environmental conditions. The document also covers energy flow through ecosystems via food chains and webs. Finally, it discusses concepts in population ecology like population growth models, limiting factors, and density-dependent and density-independent regulation of populations.
Ecology is the study of organisms and how they interact with the environment around them. An ecologist studies the relationship between living things and their habitats.
It encourages young minds to take responsibility for protecting the natural environment
protection through information and knowledge and to develop environmental awareness.
The document provides an overview of key concepts in ecology, including:
1) Ecology is the study of living organisms and their interactions with each other and their environment.
2) Ecosystems consist of biotic (living) and abiotic (non-living) components that interact, including producers, consumers, and decomposers.
3) Energy and matter transfer through trophic levels in a food web or food chain, with less available at higher levels depicted in ecological pyramids.
This document provides an overview of key concepts in ecology, including the levels of biological organization, types of cells, trophic levels, energy flow through ecosystems, and nutrient cycling. It defines important terms like population, community, ecosystem, biosphere, producers, consumers, decomposers, food chains, and food webs. It also explains how energy is lost at each trophic level and illustrates this through energy and pyramid diagrams.
Diversity & Evolution - Organisms and their environmentthejohnnth
Organisms and their environments provide key terms in ecology such as habitat, ecological niche, predator, prey, population, community, and ecosystem. Energy flows through ecosystems in a non-cyclic manner from the sun to producers to consumers in food chains and food webs, while chemical elements cycle through the ecosystem. Pollution disrupts ecosystems and affects water quality by reducing dissolved oxygen levels, with impacts including eutrophication and harm to aquatic life. Conservation aims to maintain biodiversity and use natural resources sustainably.
This document provides an overview of ecosystems, including:
1. The definition of an ecosystem as the structural and functional unit of ecology encompassing the interaction between biotic and abiotic components.
2. The key characteristics, structure, and functions of ecosystems, such as energy flow, nutrient cycling, and trophic levels.
3. Details on primary productivity, decomposition, and the flow of energy through food chains and webs within ecosystems.
The document is intended for educational purposes and provides information compiled from various sources on the basic concepts of ecosystems.
This document summarizes key concepts in ecology, including energy flow and nutrient cycling within ecosystems. It discusses how photosynthesis by autotrophs fixes energy from the sun, which is then transferred through food chains and webs to heterotrophs in a trophic pyramid. Most energy is lost at each transfer, limiting food chain length. Decomposition recycles nutrients, which are taken up by producers to continue ecosystem functioning.
An ecosystem is a community of organisms and their physical environment that interact. It includes biotic factors like producers, consumers, and decomposers, as well as abiotic factors such as climate, soil, and water. Energy flows through the ecosystem in food chains and webs while matter is recycled through biotic and abiotic interactions. Ecological succession over time leads to the development of climax communities as the environment changes.
Primary and secondary production, landscape ecology and ecological modeling.Ateeqa Ijaz
This document discusses primary production and energy flow in ecosystems. It defines primary production as the production of organic biomass by plants, algae, and other autotrophs through photosynthesis. Around 1-3% of solar energy is converted to chemical energy by primary producers. Primary production is divided into gross primary production and net primary production. Around 90% of energy is lost between trophic levels as it is transferred from primary producers to primary consumers to secondary consumers. Factors like temperature, moisture, soil nutrients influence primary production rates in terrestrial ecosystems. Primary production forms the base of the food chain and limits how much energy can be transferred to higher trophic levels due to losses at each level.
I am pleased to present an outstanding Sample ESS IA that secured an impressive 28 out of 30 marks, resulting in a remarkable 7-point score. This exemplar serves as a valuable reference and resource for your ESS class, offering comprehensive insights and invaluable guidance for both students and educators alike.
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This document outlines an investigation into the effect of carbon dioxide emissions on temperature in the USA and UK from 2009-2019. The research question asks to what extent different levels of CO2 concentration in the USA vs the UK affect average temperature. Secondary data on CO2 emissions and average temperature in both countries will be collected from credible sources over the 10-year period. The hypothesis is that there is a correlation between CO2 concentrations and temperature trends, and differences in CO2 levels between the countries will result in differences in temperature trends. Key variables are CO2 concentration as the independent variable and average temperature as the dependent variable.
The document contains contact information for ESSGurumantra.com with their Gmail ID repeated in 14 lines. It concludes by listing their social media profiles and podcast/music platforms where users can follow the organization, including their website, Facebook, YouTube channel, Twitter, Instagram, LinkedIn, SlideShare, Pinterest, Spotify, SoundCloud, and Google Podcast.
The document discusses various topics related to genetics and biotechnology including genetic engineering, polymerase chain reaction (PCR), DNA profiling, and genetically modified foods. It provides definitions and explanations of key terms and processes such as how PCR is used to amplify DNA, the steps involved in PCR including denaturation, annealing and elongation, and how gel electrophoresis can be used to analyze PCR products. It also summarizes techniques like DNA profiling that are used for forensic investigations and paternity testing.
This document contains a series of logic and reasoning puzzles to test creativity and problem-solving skills. It includes 25 puzzles of varying difficulty across several categories like word puzzles, number puzzles, and visual puzzles. The puzzles require skills like rearranging letters, words, or images to find hidden meanings and complete word or phrase patterns.
The document is an exam for the Environmental Systems Standard Level course, consisting of 30 multiple choice questions testing various concepts related to environmental science. Some of the topics covered include population ecology, energy flow, greenhouse gases, the carbon and nitrogen cycles, and atmospheric structure. The exam is 45 minutes long and candidates are instructed to choose the single best answer for each question and mark their choice on an answer sheet.
The document provides lists of top 10 websites in various categories that are useful for career development and job searching. These categories include sites for careers, in-demand tech skills in 2019, learning Excel for free, free online education, reviewing resumes for free, and preparing for interviews. The lists highlight popular websites like LinkedIn, Coursera, Khan Academy, Leetcode, and ResumeGenius that can help with tasks like networking, developing skills, getting education/training, improving resumes and interview skills.
Very interesting - Can you guess what is common between all these prominent temples.
If your answer is, they all are Shiva temples, you are only partially correct.
It is actually the longitude in which these temples are located.
They all are located in 79° longitudes. What is surprising and awesome is that how the architects of these temples many hundreds of kilometers apart came up with these precise locations without GPS
1. Madurai is unique as it is guarded by 3 surrounding hills and was once full of Kadabam trees.
2. The Nandi statue at Meenakshi Amman Temple is one of the largest in Asia. Tirumalai Naicker Mahal is the largest palace in Tamil Nadu, built without using ceiling supports.
3. Gandhi Museum was originally the palace of Ranimangammal and is the only museum dedicated to Gandhi outside of India. It houses the blood-stained shawl Gandhi was wearing when assassinated.
K.Guru Charan Kumar, IB ESS Teacher at Pathways World School, Aravali discusses the importance of taking his IB students on field trips that enhance the learning they do in the classroom. Over the past year, K. Guru has shared numerous adventures with the IB community and we asked him to reflect on why field experience is central to his teaching.
Guru Charan Kumar KANAHAVEL attended the IB Asia Pacific DP Category 1 & 2 Workshops in Singapore from August 10-12, 2012 for the subject Environmental Systems and Societies. The certificate certifies his participation in subject sessions at the workshops organized by the IB Regional Office for Asia Pacific and led by experienced IB practitioners.
My mission is to deliver world-class international education power point presentation through the provision of high-quality curricula, assessment and services for the IGCSE EVM.
A wide range of materials and resources is available through my Slide share to support teachers and learners in Cambridge schools. Resources suit a variety of teaching methods in different international contexts.
The content of this power point presentation is designed to encourage reflection on the limits to growth and sustainable development for IGCSE EVM.
The content of this PowerPoint is structured as a series of learning outcomes that lay out what candidates should know, understand and be able to analyze and discuss.
Environmental Management is concerned not only with the impact of humankind on the planet but also with the patterns of human behavior necessary to preserve and manage the environment in a self-sustaining way. Study is linked to the areas of new thinking in environmental management, environmental economics and the quest for alternative technologies. Classroom studies and optional coursework allow candidates to obtain a local as well as a global perspective.
My mission is to deliver world-class international education power point presentation through the provision of high-quality curricula, assessment and services for the IGCSE EVM.
A wide range of materials and resources is available through my Slide share to support teachers and learners in Cambridge schools. Resources suit a variety of teaching methods in different international contexts.
The content of this power point presentation is designed to encourage reflection on the limits to growth and sustainable development for IGCSE EVM.
The content of this PowerPoint is structured as a series of learning outcomes that lay out what candidates should know, understand and be able to analyze and discuss.
Environmental Management is concerned not only with the impact of humankind on the planet but also with the patterns of human behavior necessary to preserve and manage the environment in a self-sustaining way. Study is linked to the areas of new thinking in environmental management, environmental economics and the quest for alternative technologies. Classroom studies and optional coursework allow candidates to obtain a local as well as a global perspective.
My mission is to deliver world-class international education power point presentation through the provision of high-quality curricula, assessment and services for the IGCSE EVM.
A wide range of materials and resources is available through my Slide share to support teachers and learners in Cambridge schools. Resources suit a variety of teaching methods in different international contexts.
The content of this power point presentation is designed to encourage reflection on the limits to growth and sustainable development for IGCSE EVM.
The content of this PowerPoint is structured as a series of learning outcomes that lay out what candidates should know, understand and be able to analyze and discuss.
Environmental Management is concerned not only with the impact of humankind on the planet but also with the patterns of human behavior necessary to preserve and manage the environment in a self-sustaining way. Study is linked to the areas of new thinking in environmental management, environmental economics and the quest for alternative technologies. Classroom studies and optional coursework allow candidates to obtain a local as well as a global perspective.
As part of the IB philosophy, one must understand that not everything can be taught within the classroom. Thus, field trips provide the perfect opportunity to apply ourselves fruitfully. Laden with their luggage, and appetite for knowledge, the group of ESS and Geography students readied themselves for the learning expedition to Sundarbans, West Bengal.
The most engaging component of ESS & Geo IBDP is the coursework/fieldwork which culminates in an Analytical report based on Primary Data which the students gather and work upon. In this context we are all set to embark on our journey to Sundarbans Delta (UNESCO World Heritage site) which is located in Kolkata. This year 41 IBDP students with 4 teachers ventured for the very first time in the country to visit the Sundarbans(Kolkata) for the field trip.
The IBDP ESS & Geography students studied “Ecological Footprints of Eco tourism & Environmental Sustainability, Quality and Patterns of Resource Consumption” with special reference to Mangrove forest of Sundarbans, West Bengal.
Farmers from Maldevta Village, who work in the lowest sector of the economy, have minimal land and resources to help them grow crops. This obligates them to enter the hills with their cattle to allow grazing. Farmers also clear some forest areas, to increase their farm land for more income, thus reducing the biodiversity. As a result of the reduced in forest area and resources, wild animals invade villages and destroy farmlands. In some cases, because of minimal knowledge of the chemical Pesticides, it’s overuse affects not only the farmland, but also nearby water resources as it leads to eutrophication. This relates to my RQ because after surveying the villagers and collecting the raw data from the Simpson’s Diversity index it allowed me to evaluate the effect of human intervention on the natural environment and thus evaluating the effect of Ecological Footprint.
This IA talks about research is to compare Simpson Diversity of four areas of Mahendrapur village based on the amount of sunlight received and the amount of nutrients found near the place where they are located (near the water body or away from the water body).
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
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Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
Reimagining Your Library Space: How to Increase the Vibes in Your Library No ...Diana Rendina
Librarians are leading the way in creating future-ready citizens – now we need to update our spaces to match. In this session, attendees will get inspiration for transforming their library spaces. You’ll learn how to survey students and patrons, create a focus group, and use design thinking to brainstorm ideas for your space. We’ll discuss budget friendly ways to change your space as well as how to find funding. No matter where you’re at, you’ll find ideas for reimagining your space in this session.
Beyond Degrees - Empowering the Workforce in the Context of Skills-First.pptxEduSkills OECD
Iván Bornacelly, Policy Analyst at the OECD Centre for Skills, OECD, presents at the webinar 'Tackling job market gaps with a skills-first approach' on 12 June 2024
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
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1. IB ESS/GURU
IB ESS EXAM NOTES
TOPIC 1: Systems and Models
· Systems: an assemblage of parts and their relationship forming a functioning entirety or whole
o Open systems: exchanges matter and energy
o Closed systems: exchanges only energy
o Isolated systems: neither matter nor energy and is theoretical
· Laws of thermodynamics
o 1st: energy is neither created nor destroyed, only changes forms
o 2nd: the entropy of a closed system increases; when energy is transformed into work, some
energy is always lost as waste heat
Equilibrium
oSteady-state: in open systems, continuous inputs and outputs of energy and matter, system as a
whole remains in a constant state, no long term changes.
o Static: no change over time; when the state of equilibrium is distributed, the system adapts a
new equilibrium; can’t occur in living systems
o Stable: the system returns to the same equilibrium after disturbances
o Unstable: system returns to a new equilibrium after disturbances
·Feedback
o Positive: results in a further decrease of output and the system is destabilized and pushed into a
new state of equilibrium
o Negative: tends to neutralize or counteract any deviation from an equilibrium and tends to
stabilize systems
· Transfers and transformations
o Transfers:
- The movement of material through living organisms
- Movement of material in non-living process
- The movement of energy
o Transformations
- Matter to matter
- Energy to energy
- Matter to energy
- Energy to matter
· The Gaia model
2. IB ESS/GURU
o Views earth as a living organism
o The earth has a “disease”
TOPIC 2: Ecosystems
Definitions:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Biotic factors: living components
Abiotic factors: non-living physical and chemical components
Species: a particular type of organism
Population: a group of individuals of the same species living in the same area at the same
time
Habitat: the environment where a species normally lives
Ecological niche: how an organism makes a living
Community: a group of populations living and interacting with each other in a common
habitat
Ecosystem: a community of independent organisms (biotic factors) and the physical
environment (abiotic factors) which they inhabit
Biome: a collection of ecosystems sharing common climatic conditions
Respiration: a process of breaking down food in order to release energy
Photosynthesis: a process of producers making their own food (glucose) and producing
oxygen from water and carbon dioxide
Biomass: the living mass of an organism or organisms but sometimes refers to dry mass
Gross Productivity: the total gain in energy or biomass per unit area per unit time
a. o GPP: by producers
b. o GSP: by consumers
Net Productivity: the total gain in energy or biomass per unit area per unit time after
allowing for losses to respiration
a. o NPP: by producers
b. o NSP: by consumers
Biomes:
1.
2.
3.
4.
5.
climate
latitude (distance from equator)
altitude (height above sea level)
wind and water currents
P/E ratio (precipitation over evaporation ratio)
3. IB ESS/GURU
latent heat: heat that is either taken in or produced when water changes from state to state
Different Biomes:
Tropical Rainforest – hot and wet areas with broadleaved ever green forest. Within 50 north or
south of the equator. High rainfall and high temperature, high insolation as near equator. There
are amazingly high levels of biodiversity, many species and many individuals of specie. There
are very large evergreen trees, small shrubs, orchids.It is estimated that tropical rainforest
produces 40% of NPP of terrestrial ecosystems. But the problems it has, are that 50% of human
population live near the equator, so they damage the biome, they are exploited for human
economical needs.
Desert – dry areas which are usually hot in the day and cold in the night, there are tropical,
temperate and cold deserts. It covers 20-30% of earths surface, about 300 of north or south of the
equator. Water is limited in the deserts. There are few species and very low biodiversity, there
are only the ones who adapted to the conditions. Soil can be rich, because the nutrients are not
washed away from the water. NPP is low because the amount of plants and animals are limited,
because of the water. Desertification is the human activity.
Temperate Grassland – fairly flat areas, that are covered with grass, they are located 400 – 600
from the equator, either north or south. The net productivity is not very high, because its only
grass that grows on the land, nothing else. And with that the animals that are growing are small
size as well. Humans use grass lands for the crops.
Temperate Forest - mild climate and deciduous forest. Located 400 – 600 north or south of the
equator, it has 4 seasons, there also are fewer species than tropical rainforest, it has the second
highest NPP after the tropical rainforest. Much of the temperate forests, have been cleared
because of human activities.
Arctic Tundra – Tree less plain with permafrost, cold and very low precipitation, dark nights. It
is 10% of lands surface, it is located on the arctic cap. Water is limiting but the fire can stop the
climax community forming. There are no trees but there Is a thick mat, covered by mosses and
grasses. It has very low biodiversity, and soil is poor. With that the NPP is very low, humans use
it for mining.
4. IB ESS/GURU
Ecosystem Structure:
Food chains and trophic levels
1.
2.
3.
4.
5.
6.
7.
food chain: shows a flow of energy from one organism to the next
food web: shows a complex network of interrelated food chains
trophic level: a position that an organism or a group of organisms in a community
occupies in a food chain
producers or autotrophs: which manufacture their own food from inorganic substances
consumers or heterotrophs: which feed on autotrophs or other heterotrophs to obtain
energy
decomposers: consumers that obtain energy from dead organisms
detritivores: consumers that derive their food from detritus or decomposing organic
material
Ecological pyramids
1.
Pyramid of numbers: shows the number of organisms at each trophic level in a food chain
o
advantages:
o
o easy method of giving an overview
o good for comparing changes in population numbers over different times
disadvantages:
o all organisms included regardless of their size
o numbers can be too great to represent accurately
2. Pyramid of biomass: contains the biomass at each trophic level
o advantages:
overcomes the problems of pyramids of numbers
o
disadvantages:
3.
only uses samples from populations, so it’s impossible to measure biomass
exactly
organisms must be killed to measure dry mass
pyramid of productivity: contains the flow of energy through each trophic level; shows
the energy being generated and available as food to the next trophic level during a fixed
period of time
o
advantages:
o
shows the actual energy transferred and allows for rate of production
disadvantages:
very difficult and complex to collect energy data as the rate of biomass
production over time is required
4.
bioaccumulation and biomagnification
o
o
bioaccumulation: increase in concentration in one organism over time
§biomagnification: increase in concentration with the increase in trophic levels
5. IB ESS/GURU
5.
o trophic efficiency: only 10% of the energy is transferred to the next, so the trophic
efficiency=10%
Population Interactions
A population is a group of organisms of the same species living in the same area at the same time
and capable of interbreeding.
Population density is the average number of individuals in a stated area.
Competition
Competition between members of the same species is Intraspecific competition.
Individuals of the different species, competeting for the same resource is
called Interspecific competition.
The other outcome is that one species may totally outcompete the other, this is the principle
of Competitive exclusion.
Predation – happens when one animal, the predator, eats another animal, the prey.
Herbivory – is defined as an animal eating green plant.
Parasitism - is a relationship between two species in which one species lives in or on another
gaining its food from it.
Mutualism - s a relationship between two or more species in which both or all benefit and none
suffer.
Succession
Succession is the change in species composition in an ecosystem over time
It may occur on bare ground where soul formation starts the process or where no soil has already
formed, or where the vegetation has been removed.
Early in succession, GPP and respiration are low and so NPP is high as biomass accumulates.
Secondary succession occurs on souls that are already developed and ready to accept seeds
carried in by the wind. Also there are often dormant seeds left in the soil from previous
community. This shortens the number of seral stages the community goes through.
6. IB ESS/GURU
Changes occurring during a succession (refer to Fig. 14.4 on page 268)
the size of organisms increases
energy flow becomes more complex
soil depth, humus, water-holding capacity, mineral content and cycling increase
Biodiversity increases and then falls as the climax community is reached
NPP and GPP rise and then fall
Production: respiration ratio falls
Species diversity in successions
Early stages of succession: few species
Species diversity increases with the succession
Increase continues until a balance is reached between possibilities for new species to establish,
existing species to expand their range and local extinction
TOPIC 3: Human Population, Carrying Capacity and Resource Use
Population dynamics
Exponential growth or geometric growth
When the population is growing, and there are no limiting factors slowing the growth.
Density-dependent limiting factors (biotic factors when effects depend on the population
density)
· Negative feedback mechanism- lead to stability of the population
· Internal – factors act within species
1. Limited food supply lead to intraspecific competition
2. Lack of suitable territory
3. Survival of the fittest
· External – factors act between different species (predation and disease)
1. Predation – pray animals increase, predators increase -> pray decreases and the predators
decrease
2. Disease – at high populations spreads fast
7. IB ESS/GURU
S-curves
The visual picture of the curves
· Start with exponential growth
· Then the growth slows down
· Finally constant size
Other facts:
· Consistent with carrying capacity of the environment
· Environmental resistance
Density-independent limiting factors (abiotic factors when effects do not depend on the
population density)
· Climate
· Weather
· Volcanic eruptions
· Floods
J- curves
· “Boom and bust” – population grows exponentially and suddenly collapses
· The collapse is referred to as overshoot
· The sudden collapse usually caused by abiotic factors
· The J-curves usually occur in:
1. Microbes
2. Invertebrates
3. Fish
4. Small mammals
K-and r-selected species
K-selected species
· Long life
· Slower growth
· Late maturity
· Fewer large offspring
· High parental care and protection
· High investment in individual offspring
· Adapted to stable environment
· Later stages of succession
· Niche specialists
· Predators
· Regulated mainly by internal factors
· Higher trophic level
· Trees, albatrosses, humans
8. IB ESS/GURU
r-selected species
· Short life
· Rapid growth
· Early maturity
· Many small offspring
· Little parental care or protection
· Little investment in individual offspring
· Adapted to unstable environment
· Pioneers, colonizers
· Niche generalists
· Prey
· Regulated mainly by external factors
· Lower trophic level
· Examples: annual plants, flour beetles, bacteria
K-and r-selected species are extremes of a continuum. Many species are mixture of both
characteristics.
Demographics – study of the dynamics of the population change.
Human Development Index – measure:
1. Life expectancy
2. Well being
3. Standards of living
4. GDP
MEDC- industrialized nations with high GDPs.
LEDC- less industrialized nations with lower GDP
Population growth effects on the environment
More people- more recourses- more waste- greater impact
Factors that affect population size:
· Crude birth rate – number of births per thousand individuals in population per year
· Crude death rate – the number of deaths per thousand individuals in a population per
year.
· Immigration
· Emigration
· Natural increase rate – (crude birth rate – crude death rate) / 10, which, gives the
natural increase rate as a percentage. It excludes the effects of migration.
9. IB ESS/GURU
· Total fertility rate – the average number of children each woman has over her lifetime.
· Fertility rate – the number of births per thousand women of childbearing age. In
reality, replacement fertility ranges from 2.03 in MEDCs to 2.16 in LEDCs because of
infant and childhood mortality.
· (Fertility is sometimes considered a synonym for the birth rate)
Human population growth
Demography is the study of the statistical characteristics of human populations, e.g. total
size, age and sex composition ad changes over time with variations in birth and death rates.
· Carrying capacity – the maximum number of a species or “load” that can be sustainably
supported by a given environment, without destroying the stock
· Populations remain stable when birth rate = death rate
· The size of the population is depended on the wealth of the population
· Demand for and the exchange of the resources effects the size
· All of the above differs in MEDCs and LEDCs
Population growth and food shortages
There are two main theories relating to population growth and food supply, from Malthus
and Boserup
Malthusian theory
· Thomas Malthus – English clergyman and economist (1766 to 1834)
· Published an essay on the principle of population in 1798
· Claimed that food supply was the main limit to population growth
· Believed that human population increases geometrically, whereas food supplies grows
arithmetically, and as a result, there are much more humans than food supplies
Limitations of Malthusian theory
· Too simplistic
· Shortage of food is just one possible explanation for the slowing in population growth
· It is only poor who go hungry
· Globalization is something Malthus could not have expected
Boserup’ theory
· Ester Boserup, a Danish economist (1965)
· Increase in population would stimulate technologists to increase food production
· Rise in population will increase the demand for food and so act as an incentive to change
agrarian technology and produce more food
10. IB ESS/GURU
· Belief that “necessity is the mother of invention”
Limitations of Boserup’s theory
· Too simplistic view
· Like Malthus, his idea is based on the assumption of a “closed” community.
· Emigration and immigration are not considered
· Overpopulation can lead to unsuitable faming
Family sizes
· Appears that decision to have children is not correlated with GNP of a country nor personal
wealth:
· High infant and childhood mortality
· Security in old age
· Children are an economic asset in agricultural societies
· Status of women
· Unavailability of contraception
The ways to reduce the family size are to:
· Provide education
· Improve health
· Provide contraception
· Increase family income
· Improve resource management
Population Pyramids
These pyramids show how many individuals are alive in different age groups (five-year
cohorts) in a country for any given year. They also show the frequency of males and females.
In the pyramids, population numbers are on the x-axis and the age groups on the y-axis.
The shapes of the pyramids are following:
· Expanding (stage 1) – high birth rates; rapid fall in each upward age group due to high
death rates; short life expectancy.
· Expanding (stage 2) – high birth rates; fall in death rates as more living to middle age;
slightly longer life expectancy.
· Stationary (stage 3) – declining birth rate; low death rate’ more people living to old age.
· Contracting (stage 4) – low birth rate; low death rate; higher dependency ratio; longer life
11. IB ESS/GURU
expectancy.
Demographic transition model:
Demographic transition model describes the pattern of decline in mortality and fertility
(natality) of a country as a result of social and economic development.
This model can be described as a five-stage population model, which can be linked to the
stages of the sigmoid growth curve.
The stages are:
Pre- industrial society:
· High birth rate due to no birth control;
· High infant mortality rates;
· Cultural factors encouraging large families.
· High death rates due to disease, famine, poor hygiene and a little medicine.
LEDC:
· Death rate drops as sanitation and food improve,
· Disease is reduced so lifespan increases.
· Birth rate is still high so population expands rapidly
· Child mortality falls due to improved medicine.
Wealthier LEDC:
· Birth rats fall due to access to contraception.
· Improved health care, education and emancipation of women.
· Population begins to level off and desire for material goods and low infant death rates mean
that people have smaller families.
MEDC:
· Low birth rates
· Low death rates
· Industrialized countries
· Stable population sizes
MEDC:
· Population may not be replaces as fertility rate is low.
· Problems of aging workforce.
Food Resources
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Undernourishment, malnourishment – Lack of essential nutrients like proteins, vitamins,
minerals.
Agriculture
Types of farming systems
Subsistence farming – the provision of food by farmers for their own families or the local
community
Cash cropping- growing the food for the market
Commercial farming- large, profit- making scale maximizing yields per hectare.
(monoculture)
One type of crop or animal is produced.
Extensive farming – more land with lower density of stocking or planting and lower inputs
and corresponding outputs.
Intensive farming – using the land more intensively with high levels of input and output per
unit area.
Pastoral farming – raising animals on a land which is not suitable for crops.
Arable farming is sowing crops on good soils to eat directly or to feed to animals
Mixed farming – has both animals and crops and is a system in itself where animals waster is
used to fertilize the crops and improve soil structure.
Farming’s energy budget
A system with inputs, outputs, storages and flows = marketable product sold by weight
Energy balance in farming = fuel, labor, any other energy, soil, sow the seed, harvest the
crop, prepare and package, transport, energy cost of dealing with waster products.
Grain equivalent – the quantity of wheat grain that would have to be used to produce one kg
of that product.
Rice Production in Borneo
Traditional, extensive rice production in Indonesian Borneo
13. IB ESS/GURU
- Low inputs of energy and chemicals, high labor intensity and a low productivity.
- No fertilizers and pesticides used
- Rice yield is only output (no pollution)
Intensive rice production in California
- high inputs of energy and chemicals, low labor intensity and a high productivity
- diesel and petrol
- fertilizers (N, P) Pesticides (insecticides and herbicides)
- More energy input than output
- More pollution
Fisheries – industrial hunting
According to FAO more than 70% of the world’s fisheries are fully exploited, in decline or
seriously depleted.
The global fish catch is in decline even though technology has improved.
Demand is high and rising but fisherman cannot find or catch enough fish because they are no
longer there
The tragedy of the commons - Tension between the common good and the needs of the
individual and how they can be in conflict.
Exploitation of the oceans is the tragedy of the commons
The Grand Banks off the coast of Newfoundland were once among the richest fishing grounds on
Earth. Since 1400s it’s been depleted by various countries.
The United Nations Convention on Law of the Sea (UNCLOS) – international agreement written
over decades that attempts to define the rights and responsibilities of nations with respect to the
seas and marine resources.
Maximum Sustainable Yield (MSY)
Sustainable Yield – increase in natural capital
Sustainable yield of the aquifer is the amount that can be taken each year without permanently
decreasing the amount of water stored.
14. IB ESS/GURU
SY = annual growth and recruitment – annual death and immigration
Harvesting MSY leads to population decline and thus loss of resource base and an unsustainable
industry or fishery.
Optimal Sustainable Yield (PSY) – half the carrying capacity. Safety margin than MSY ut still
may have an impact on population size with other environmental impacts.
Resources- Natural Capital
Natural Capital - Natural resources, services that support life, natural processes. The Goods and
services that are not manufactured but have value to humans.
Natural Income – (yield, harvest, services) Yield from the natural capital.
Renewable Resources – living resources that can replace or restock themselves. (Alternative
energy resources)
Non-renewable resources- exist in finite amounts on Earth and are not renewed or replaced after
they have been used or depleted. (Minerals and fossil fuels)
Replenishable Resources – replaceable but take long period of time. (Groundwater)
Sustainability – living within the means of nature, on the “interest” or sustainable natural income
generated by natural capital.
“Tragedy of commons”- many individuals who are acting in their own self-interest to harvest a
resource may destroy the long-term future of that resource so there is none for anyone.
Resource Values
Economic – marketable goods and services
Ecological- life-support services
Scientific/technological - applications
Intrinsic – aesthetic, cultural, spiritual
Urbanization – the drifts from the countryside to urban life. Urbanization might eventually
encroach on or degrade natural habitats of the cities.
Globalization- Every society on Earth is connected and unified into a single functioning entity.
(Global trade) Globalization often leads to westernization. Globalization has facilitated the
process of global agreements on global issues.
15. IB ESS/GURU
Human Carrying Capacity – Maximum number or load of individuals that an environment can
sustainably carry or support.
Ecocentric - reduce the use of non-renewable resources and minimize their use of renewable
ones.
Technocentric – human carrying capacity can be expanded continuously through technological
innovation and development.
Conventional Economists – trade and technology increase the carrying capacity.
Ecological Economists – technological innovation can only increase the efficiency with which
natural capital is used.
Reuse- object is used more than once. (Drink bottles, secondhand cars)
Recycling – objects material is used again to manufacture a ne product. (Aluminum)
Remanufacturing – object’s material is used to make a new objects of the same type. (Plastic
bottles)
Absolute Reductions – use fewer resources (energy, paper)
Ecological footprint – area of land that would be required to sustainably provide all of a
particular population’s resources and assimilate all its wastes.
Population dynamics
Exponential growth or geometric growth
When the population is growing, and there are no limiting factors slowing the growth.
Density-dependent limiting factors (biotic factors when effects depend on the population
density)
· Negative feedback mechanism- lead to stability of the population
· Internal – factors act within species
1. Limited food supply lead to intraspecific competition
2. Lack of suitable territory
3. Survival of the fittest
· External – factors act between different species (predation and disease)
1. Predation – pray animals increase, predators increase -> pray decreases and the predators
decrease
2. Disease – at high populations spreads fast
S-curves
The visual picture of the curves
· Start with exponential growth
· Then the growth slows down
· Finally constant size
Other facts:
16. IB ESS/GURU
· Consistent with carrying capacity of the environment
· Environmental resistance
Density-independent limiting factors (abiotic factors when effects do not depend on the
population density)
· Climate
· Weather
· Volcanic eruptions
· Floods
J- curves
· “Boom and bust” – population grows exponentially and suddenly collapses
· The collapse is referred to as overshoot
· The sudden collapse usually caused by abiotic factors
· The J-curves usually occur in:
1. Microbes
2. Invertebrates
3. Fish
4. Small mammals
K-and r-selected species
K-selected species
· Long life
· Slower growth
· Late maturity
· Fewer large offspring
· High parental care and protection
· High investment in individual offspring
· Adapted to stable environment
· Later stages of succession
· Niche specialists
· Predators
· Regulated mainly by internal factors
· Higher trophic level
· Trees, albatrosses, humans
r-selected species
· Short life
· Rapid growth
· Early maturity
17. IB ESS/GURU
· Many small offspring
· Little parental care or protection
· Little investment in individual offspring
· Adapted to unstable environment
· Pioneers, colonizers
· Niche generalists
· Prey
· Regulated mainly by external factors
· Lower trophic level
· Examples: annual plants, flour beetles, bacteria
K-and r-selected species are extremes of a continuum. Many species are mixture of both
characteristics.
Demographics – study of the dynamics of the population change.
Human Development Index – measure:
1. Life expectancy
2. Well being
3. Standards of living
4. GDP
MEDC- industrialized nations with high GDPs.
LEDC- less industrialized nations with lower GDP
Population growth effects on the environment
More people- more recourses- more waste- greater impact
Factors that affect population size:
· Crude birth rate – number of births per thousand individuals in population per year
· Crude death rate – the number of deaths per thousand individuals in a population per year.
· Immigration
· Emigration
· Natural increase rate – (crude birth rate – crude death rate) / 10, which, gives the natural
increase rate as a percentage. It excludes the effects of migration.
· Total fertility rate – the average number of children each woman has over her lifetime.
· Fertility rate – the number of births per thousand women of childbearing age. In
reality, replacement fertility ranges from 2.03 in MEDCs to 2.16 in LEDCs because of infant
and childhood mortality.
· (Fertility is sometimes considered a synonym for the birth rate)
Human population growth
Demography is the study of the statistical characteristics of human populations, e.g. total size,
age and sex composition ad changes over time with variations in birth and death rates.
18. IB ESS/GURU
· Carrying capacity – the maximum number of a species or “load” that can be sustainably
supported by a given environment, without destroying the stock
· Populations remain stable when birth rate = death rate
· The size of the population is depended on the wealth of the population
· Demand for and the exchange of the resources effects the size
· All of the above differs in MEDCs and LEDCs
Population growth and food shortages
There are two main theories relating to population growth and food supply, from Malthus and
Boserup
Malthusian theory
· Thomas Malthus – English clergyman and economist (1766 to 1834)
· Published an essay on the principle of population in 1798
· Claimed that food supply was the main limit to population growth
· Believed that human population increases geometrically, whereas food supplies grows
arithmetically, and as a result, there are much more humans than food supplies
Limitations of Malthusian theory
· Too simplistic
· Shortage of food is just one possible explanation for the slowing in population growth
· It is only poor who go hungry
· Globalization is something Malthus could not have expected
Boserup’ theory
· Ester Boserup, a Danish economist (1965)
· Increase in population would stimulate technologists to increase food production
· Rise in population will increase the demand for food and so act as an incentive to change
agrarian technology and produce more food
· Belief that “necessity is the mother of invention”
Limitations of Boserup’s theory
· Too simplistic view
· Like Malthus, his idea is based on the assumption of a “closed” community.
· Emigration and immigration are not considered
· Overpopulation can lead to unsuitable faming
Family sizes
· Appears that decision to have children is not correlated with GNP of a country nor personal
19. IB ESS/GURU
wealth:
· High infant and childhood mortality
· Security in old age
· Children are an economic asset in agricultural societies
· Status of women
· Unavailability of contraception
The ways to reduce the family size are to:
· Provide education
· Improve health
· Provide contraception
· Increase family income
· Improve resource management
Population Pyramids
These pyramids show how many individuals are alive in different age groups (five-year cohorts)
in a country for any given year. They also show the frequency of males and females. In the
pyramids, population numbers are on the x-axis and the age groups on the y-axis.
The shapes of the pyramids are following:
· Expanding (stage 1) – high birth rates; rapid fall in each upward age group due to high death
rates; short life expectancy.
· Expanding (stage 2) – high birth rates; fall in death rates as more living to middle age; slightly
longer life expectancy.
· Stationary (stage 3) – declining birth rate; low death rate’ more people living to old age.
· Contracting (stage 4) – low birth rate; low death rate; higher dependency ratio; longer life
expectancy.
Demographic transition model:
Demographic transition model describes the pattern of decline in mortality and fertility (natality)
of a country as a result of social and economic development.
This model can be described as a five-stage population model, which can be linked to the stages
of the sigmoid growth curve.
20. IB ESS/GURU
The stages are:
Pre- industrial society:
· High birth rate due to no birth control;
· High infant mortality rates;
· Cultural factors encouraging large families.
· High death rates due to disease, famine, poor hygiene and a little medicine.
LEDC:
· Death rate drops as sanitation and food improve,
· Disease is reduced so lifespan increases.
· Birth rate is still high so population expands rapidly
· Child mortality falls due to improved medicine.
Wealthier LEDC:
· Birth rats fall due to access to contraception.
· Improved health care, education and emancipation of women.
· Population begins to level off and desire for material goods and low infant death rates mean that
people have smaller families.
MEDC:
· Low birth rates
· Low death rates
· Industrialized countries
· Stable population sizes
MEDC:
· Population may not be replaces as fertility rate is low.
· Problems of aging workforce.
Energy Resources
· Source – sun.
· Fossil fuels are sources of stored energy from the sun
· Oil is the economy’s largest source at the moment, supplying 37% of all the energy we use.
· Coal is the next largest, supplying 25%
· Natural gas supplying 23%
How much longer for fossil fuels?
The common estimates include:
21. IB ESS/GURU
· Oil – 50 years
· Natural gas – 70 years
· Coal - 250 years
· Will eventually run out, as they are non-renewable energy sources.
Depends on:
· Our rate of use
· Technologies
· Efficiency of humans
· How successful humans are at finding new sources
· How successful humans are at finding and extracting more.
· If the wealth of humans increase
· The population of humans
· Demand increase or decrease
Evaluation of energy sources and their advantages and disadvantages
Non-renewable
Coal (fossil fuel)
From
· Fossilized plants laid down in the carboniferous period
· Mined from seams of coal which are in strata between other types of rock
· May be open cast mined (large pits) or by tunnels underground.
· Burnt to provide heat directly or electricity by burning to turbines in power stations.
Advantages
· Plentiful supply
· Easy to transport and solid
· Needs no processing
· Relatively cheap to mine and convert to energy by burning
· Up to 250 years of coal left
Disadvantages
· Non-renewable energy source
· Cannot be replaced once used (same for oil and gas)
· Burning releases carbon dioxide which is a greenhouse gas
· Some coals contain up to 10% sulfur.
· Burning sulfur forms sulfur dioxide which causes acid deposition
· Particles of soot from burning coal produce smog and lung disease.
· Coal mines leave degraded land and pollution.
· Lower heat of combustion than other fossil fuels (less energy released per unit mass)
22. IB ESS/GURU
Oil (fossil fuel)
From
· Fossilized plants and micro-organisms that are compressed to a liquid and found in porous
rocks
· Crude oil is refined by fractional distillation to give a variety of products from lighter jet fuels
and petrol to heavier diesel and bitumen.
· Extracted by oil wells.
· Many oil fields are under the oceans so extraction is dangerous
· Pipes are drilled down to the oil-bearing rocks to pump the oil out.
· Most of the world economy runs on oil either burnt directly in transport and industry or to
generate electricity
Advantages
· High heat of combustion
· Many uses
· Once found is relatively cheap to mine
· Easily converted into energy
Disadvantages
· Only a limited supply
· May run out in 20-50 years
· Gives off carbon dioxide when burned
· Oil spill danger from tanker accidents.
· Risk of terrorism in attacking oil pipes
· Greenhouse gas effect
Natural gas (fossil fuel)
From
· Methane gas and other hydrocarbons trapped between seams of rock
· Extracted by drilling like crude oil
· Often found with crude oil
· Used directly in homes for domestic heating and cooking
Advantages
· Highest heat of combustion
· Lot of energy gained from it
· Ready- made fuel
23. IB ESS/GURU
· Relatively cheap form of energy
· Cleaner fuel than coal and oil
Disadvantages
· Only limited supply of gas but more than oil
· About 70 years left (according to current usage)
· Gives off carbon dioxide but only half as much per unit of energy produced as coal
Nuclear fission
From
· Uranium is the raw material. This is a radioactive and is split in nuclear reactors by bombarding
it with neutrons
· As it splits into plutonium and other elements, massive amounts of energy are also released
· Uranium is mined
· Australia has the most known reserves
· Canada exports the most
· Other countries have smaller amounts
· About 80 years worth left to mine at current rates
· Could be extracted from sea water
Advantages
· Raw materials are relatively cheap once the reactor is built and can last quite a long time
· Small mass of radioactive material produces a huge amount of energy
· No carbon dioxide released nor other pollutants (unless there are accidents)
Disadvantages
· Extraction costs high.
· Nuclear reactors are expensive to build and run
· Nuclear waste is still radioactive and highly toxic
· Big question of what to do with it
· Needs storage for 1000s of years
· May be stored in mine shafts or under the sea
· Accidental leakage of radiation can be devastating.
· Accidents are rare but worst nuclear reactor accident at Chernobyl, Ukraine was in 1986
· Risk of uranium and plutonium being used to make nuclear weapons
Renewable
24. IB ESS/GURU
Hydroelectric power (HEP)
From
· Energy harnessed from the movement of water through rivers, lakes and dams to power
turbines to generate electricity
· Pumped-storage reservoirs power turbines
Advantages
· High quality energy output compared with low quality energy input
· Creates water reserves as well as energy supplies.
· Reservoirs used for recreation, amenity
· Safety record is good.
Disadvantages
· Costly to build
· Can cause the flooding of surrounding communities
· Dams have major ecological impacts on local hydrology
· Silting of dams
· Downstream lack of water
· Risk of flooding if dam bursts
Biogas
From
· Decaying organic plant or animal waste are used to produce methane in biogas generators or
burnt directly as dung/plant material
· More processing can give oils which can be used as fuel in vehicles instead of diesel fuel =
biofuels
Advantages
· Cheap
· Available
· If the crops are replanted, biogas can be a long-term, sustainable energy source
Disadvantages
· May be replacing food crops on a finite crop land and lead to starvation
25. IB ESS/GURU
· When burnt, it still gives off atmospheric pollutants, including greenhouse gases.
· If crops are not replanted, biomass is a non-renewable resource.
Wood
From
· Felling or copping trees.
· Burnt to generate heat and light
Advantages
· Cheap
· Available
· If the crops are replanted, biogas can be a long-term, sustainable energy source
Disadvantages
· Low heat of combustion
· Not much energy released for its mass
· When burnt, it gives off atmospheric pollutants, including greenhouse gases
· If trees are not replanted wood is a non-renewable resource.
· High cost of transportation as high volume.
Solar photo volcanic cells
From
· Conversion of solar radiation into electricity via chemical energy
Advantages
· Infinite energy supply
· Safe
· Low quality energy converted to high.
Disadvantages
· Manufacture and implementation of solar panels can be costly.
· Need sunshine, do now work in the dark
Solar-passive
From
· Using buildings or panels to capture and store heat
26. IB ESS/GURU
Advantages
· Minimal cost if properly designed.
Wind
From:
· Can be found singly, but usually many together in wind farms
Advantages
· Clean energy and supply once turbines made
· Little maintenance required
Disadvantages
· Need the wind to blow
· Often windy sites not near highly populated areas
· Manufacture and implementation of wind farms can be costly
· Noise pollution
· Some local people object to on-shore wind farms, arguing that it spoils countryside
· Question of whether birds are killed or migration routes disturbed by turbines
Tidal
From:
· The movement of sea water in and out drives turbines
· A tidal barrage is built across estuaries, forcing water through gaps
· In future underwater turbines may be possible out at sea and without dam
Advantages
· Should be ideal for an isolated country such as the UK
· Potential to generate a lot of energy this way
· Tidal barrage can double as bridge, and help prevent flooding
Disadvantages
· Very costly
· Few estuaries are suitable
· Opposed by some environmental groups as having a negative impact on wildlife
· May reduce tidal flow and impede flow of sewage out to sea
Wave
From
· The movement of sea water in and out of cavity on the shore compresses trapped air, driving a
27. IB ESS/GURU
turbine
Advantages
· Should be ideal for an island country
· These are more likely to be small local operations
· Can be done on a national scale
Disadvantages
· Construction can be costly
· May be opposed by local or environmental groups.
· Storms may damage them
Geothermal
From
· It is possible to use the heat inside the Earth in volcanic regions.
· Cold water is pumped into the Earth and comes out as steam
· Steam can be used for heating or to power turbines creating electricity.
Advantages
· Infinite energy supply
· Is used successfully in some countries, such as New Zealand.
Disadvantages
· Can be expensive to set up
· Only works in areas of volcanic activity
· Geothermal activity might calm down, leaving power station redundant
· Dangerous underground gases have to be disposed carefully
Nuclear fusion – energy can be released by the fusion of two nuclei of light elements
TOPIC 4: Biodiversity and Conservation
28. IB ESS/GURU
Background and Mass Extinctions
background extinction rate- natural extinction rate for species
E. O. Wilson- a biologist at Harvard, thinks that the current rate of extinction is 1000 times the
background rate and is caused by human activities
hotspots- areas where species are more vulnerable to extinction
Biologists thing: we are the sixth mass extinction called the Holocene extinction event
To see all 6 mass extinctions refer to the Table on page 95
The Sixth Mass Extinction
1.
2.
3.
4.
5.
6.
far greater than any in the past
already wiped out many large mammal and flightless bird species
humans alter the landscape on an unprecedented scale
previous mass extinctions were due to physical (abiotic) causes over long time spans
current mass extinction is caused by humans (biotic causes) and is accelerating
humans:
1. transform the environment
2. overexploit other species
3. introduce alien species
4. pollute the environment
5. Worldwide Fund for Nature produces periodic report called the Living Planet
Report
6. o measures trends in the Earth’s biological diversity
7. two phases to the sixth mass extinction
8. o 1. when modern humans spread over the Earth about 100 000 years ago
9. o 2. when humans became farmers 10 000 years ago
Hotspots
some regions have more biodiversity than others
in hotspots there are unusually high numbers of endemic species- those only found in that place
tend to be nearer the tropics and are often tropical forests
tend to have large densities of human habituation nearby
Keystone Species
species that have a bigger effect on their environment than others
act as keystone in an arch, holding the arch together
their disappearance can have an impact far greater than and not proportional to
their numbers or biomass
4. o could destroy the ecosystem or imbalance it greatly
1.
2.
3.
29. IB ESS/GURU
Example: elephants in the African savanna act as engineers, removing trees, after which grasses
can grow
Types of Diversity
1.
Biodiversity- the numbers of species of different animals and plants in different places
a. o can be considered at three levels:
i. Genetic diversity- the range of genetic material present in a species or a
population
ii. Species diversity- the number of different species within a given area or
habitat
iii. Habitat diversity- the number of different habitats per unit area that a
particular ecosystem or biome contains
b. Simpson’s diversity index- measure species diversity in an area
i. o Simpson’s reciprocal index- in which 1 is the lowest diversity
ii. where N = the total number of organisms of all species and n = the total
number of organisms of a particular species
How New Species Form
Charles Darwin proposed the theory of evolution which is outlined in The Origin of
Species, published in 1859
2. The theory is summarized bellow
a. o Speciation- when species are formed by gradual change over a long time
b. o when populations of the same species become separated, they cannot interbreed
and may start to diverge if the environments they inhabit change
c. o separation may have geographical or reproductive causes; humans speed up
speciation by artificial selection of plants and animals and by genetic engineering
d. o over time the population gradually changes= natural selection
e. o “the survival of the fittest”
1.
o
o
o
Physical Barriers (examples of species and speciation)
o Large flightless birds (e.g. emu, ostrich, rhea, cassowary) only found in Africa, Australia,
South America
o cichlid fish in the lakes of East Africa, Lake Victoria, Lake Tanganyika, Lake Malawi
o Llamas and camels (llamas in South America and camels in Africa and central Asia)
30. IB ESS/GURU
Land bridges: allow species to invade new areas
Continental drift: the movement of tectonic plates
Plate tectonics: the study of the movement of plates (continental drift)
Plates may either slide past each other, diverge, or converge
Factors that help to maintain the biodiversity
complexity of the ecosystem
stage of succession
(lack of) limiting factors
inertia
Factors that lead to loss of biodiversity
Natural hazards
loss of habitat
fragmentation of habitat
pollution
overexploitation
introducing non-native (exotic species)
spread of disease
modern agricultural practices
What makes a species prone to extinction?
narrow geographical range
small population size of reclining numbers
low population densities and large territories
few populations of the species
a large body
low reproductive potential
seasonal migrants
poor dispersers
specialized feeders or niche requirements
hunted for food or sport
minimum viable population size: that is needed for a species to survive in the wild is a figure that
scientists and conservationists consider
Species Examples (recovered, extinct, endangered)
o
Recovered Species
Australian saltwater crocodile
31. IB ESS/GURU
o
18 out of 23 were once endangered
listed as protected species in Australia in 1971
overexploited for skin (leather), meat and body parts through illegal hunting, poaching and
smuggling
restored through ranching and closed-cycle farming
Golden lion tamarin (GLT) recovered or not?
small monkey
endemic to Atlantic coastal rainforests of Brazil
omnivores
only 2% of their native habitat is left
poachers earn US$20 000 for skin
captive breeding program
some re-introduced to the wild but with only 30% of success
their future uncertain
Extinct Species
o
o
Thylacine (Tasmanian tiger)
life expectancy of 12-14 years
habitat: open forests and grassland
competed with dingoes on the mainland of Australia
hunted by farmers whose stock of sheep was the species’ prey
hunting, poisoning, and trapping
shooting parties organized for tourists’ entertainment
last one has been killed in 1930
now introduced dogs have taken over the ecological role of the thylacine
Dodo
large flightless bird endemic to the island of Mauritius
ground-nesting bird
1505 Portuguese sailors ate dodo as a source of fresh meat
new species introduced that ate dodo
humans killed the birds for sport
destruction of habitat
extinct by 1681
fauna impoverished by its loss
became an icon due to its apparent stupidity
Endangered species
32. IB ESS/GURU
o
o Rafflesia
tropical parasitic plant in the forests of South-East Asia
single sexed
pollination must be carried out when the plant in bloom
vulnerable because they need specific conditions to survive
deforestation and logging destroy their habitat
now there are Rafflesia sanctuaries
TOPIC 5: Pollution Management
· Pollution: the addition of substances to the biosphere by human activity, at a rate greater than
could be rendered harmless by the env-t
- Major sources of pollution (table on p. 277)
· Combustion of fossil fuels
· Domestic waste
· Industrial waste
· Agricultural waste
- Point source pollution
· the release of pollutants from a single, clearly identifiable site(e.g factory chimney, waste
disposal pipe)
· easier to locate à easier to manage
- Non-point source pollution: the release of pollutants from numerous, widely dispersed origins
(e.g. vehicles, chemical spreads on fields)
· Difficult to locate
· General restrictions could be put to control it
Detection and monitoring of pollution
· Indicator species: species that are only found if the conditions are either polluted or unpolluted
- Biochemical oxygen demand (BOD)
· The measure of the amount of dissolved oxygen required to break down the organic material in
a given volume of water through aerobic biological activity
· Indirect pollution measurement
· Higher BODà more pollution
33. IB ESS/GURU
- Biotic index
· A 1 to 10 scale
· Gives a measure of the quality of an ecosystem by the presence and abundance of the species
living in it
· Indirect method
· Used at the same time as BOD measurements
- Three-level model of pollution management
· a model for reducing the impact of pollutants
· “replace, regulate, restore” model
· Refer to figure 15.3 on page 282
· Pollution management strategies (refer to case study on p282-283)
- Domestic Waste (Solid domestic waste or municipal solid waste)
· Makes up about 5% of total waste
· 3kg of solid waste per capita in USA
· solid waste production has risen from 300kg per year in 1985 to 500
Strategies to minimize waste
- Recycling
· Collecting and separating waste materials and processing them for reuse
· E.g. aluminum cans
o Only 5% of energy needed to recycle it
o Can be recycled indefinitely
- Disposal of waste: Landfill
· Waste buried in a suitable site
· Lined with special plastic liner to prevent leachate (liquid waste) from seeping out
· Produced methane could be used to generate electricity
- Disposal of waste: Incinerators
· Burning of waste at high temperatures
· Heat produced is used (heat-to-energy incineration)
· Smaller land area used than in landfill
· Ash from incinerators could be used in road building
· Expensive
- Disposal of waste: organic waste
· Could be composted or put into anaerobic digesters
· Produced methane could be used as fuel
34. IB ESS/GURU
Eutrophication
· The addition of excess nutrients to a freshwater ecosystem
· Could be a natural process
· Usually nitrates and phosphates from: detergents, fertilizers, sewage etc.
- The process of eutrophication
· Fertilizers wash into a river or lake
· High levels of phosphate allow faster algae growth
· Algal blooms block the sunlight
· More algaeà more food for zooplanktonàmore food for fishàless zooplankton
· Algae die and are decomposed
· Not enough oxygen in wateràfood chains collapseàorganisms die
· Dead organic material forms sediments on the river bed and turbidity increases
· A clear blue lake is left
Reduces biodiversity in slow-moving water bodies, temporary reduction in biodiversity in fastmoving waters
- Eutrophication management strategies (refer to table 15.4 on p. 287)
- Impacts of eutrophication
· Bad smell
· Rivers/lakes covered by green algal scum and duckweed
· Anaerobic water (oxygen-deficient)
· Loss of biodiversity and shortened food chains
· Death of higher plants
· Death of aerobic organisms – invertebrates, fish and amphibians
· Increased turbidity
Introduction to ozone
Found in stratosphere, where it blocks UV radiation, and troposphere
- Depletion of stratospheric ozone
· The ozone layer
o Reactive gas mostly found between 20 and 40km altitude
o Made from oxygen (O2)
o UV radiation is absorbed in its formation and destruction
o The ozone layer absorbs more than 99% of UVC radiation
35. IB ESS/GURU
· Damaging effects of UV radiation
o Mutation
o Damage to photosynthetic organisms
o Damage to consumers of photosynthetic organisms
oC
- The action of ozone depleting substances
· Liming lakes: adding powdered limestone raises the pH but the effects are short-lived
· Reducing emissions: reducing combustion of fossil fuels
o Precombustion: removing sulfur from the fuel before combustion
o “end of pipe measures”
TOPIC 6: The Issue of Global Warming
TOPIC 7: Environmental Value Systems
Environmental philosophies
o Ecocentric: life-centered, respects rights of the nature and the dependence of humans on nature
o Technocentric/Anthropocentric: human-centered, humans are not dependent on nature, but
nature is there to benefit the human kind
Technocentric worldviews
o Cornucopians: people who see the world having infinite resources to benefit humanity. Believe
that the env-tal problems could be solved with technologies, improving our living standards
o Env-tal managers(stewardship): believe that we have an ethical duty to protect the nature.
Support limited limiting resource exploitation. Believe that if we look after the planet, it looks
after us
· Nurturing vs. intervening or manipulative approaches= environmental vs. technocentric
worldviews
Ecocentric worldviews
Biocentric: all life has an inherent value, not just for humans. Some philosophies believe
that humans aren’t any more important than other species.
Soft technologists: believe in small-scale local community action and emphasize the role
of individuals making a difference
Deep ecologies: put more value on nature than humanity. Believe in biorights – universal
rights of all species and ecosystems; advocate strong policy and population change
Various environmental worldviews
o Communism and capitalism in Germany
- disregarding value of the environment and exploiting resources
o Native American
- Use low impact technologies and respect nature
- Polytheistic religion believes that animals and plants have a spirituality
o Modern Western
- view earth as a resource for humanity.
36. IB ESS/GURU
- Ecofeminists
· argue that it is the rise of male-dominated species that has led to our view of nature as a
foe
o Buddhism’s view
- believe that we are all dependent on each other and preaches that all being are equal
- believe that all living organisms share the conditions of birth, old age, suffering and
death