This document discusses key concepts in population ecology. It begins by defining a population as a group of the same species that lives in the same area. Factors that affect population size include biotic factors like resources, competition, predation, and intrinsic factors like adaptations. Populations are characterized by their range, density, and dispersion patterns. Population growth follows exponential or logistic models and is regulated by density-dependent and density-independent factors like resources and environment. Reproductive strategies vary along a continuum from r-selected to K-selected. Human population growth has followed an exponential pattern due to advances in medicine and technology.
This document provides an overview of key concepts in population ecology. It discusses how populations are characterized by factors like range, dispersion, and density. Population size is determined by birth and death rates, which are influenced by both biotic and abiotic factors. Populations can grow exponentially without constraints but typically experience logistic growth limited by carrying capacity. Life history strategies like r-selected and K-selected influence patterns of reproduction and survivorship. Introduced invasive species sometimes grow rapidly without native controls.
Population ecology examines populations of species and how they change over time. Key features of populations include size, density, and dispersion. Population size is affected by birth and death rates. Density is measured as the number of individuals per unit area and is affected by factors like immigration, emigration, and environmental limits. Dispersion describes how organisms are spaced relative to each other, which can be clumped, even, or random. Populations can grow exponentially at first but eventually reach carrying capacity, where growth levels off due to environmental limits.
This document summarizes key concepts in population ecology, including factors that influence population size and distribution patterns. Populations can exhibit clumping, uniform, or random dispersion patterns depending on resource availability and other factors. A population's size is determined by the balance between birth and death rates, which are influenced by biotic potential and environmental resistance. Humans can impact ecosystems through activities like habitat degradation and overharvesting. Sustainable practices can be informed by principles seen in nature, such as nutrient recycling and population control.
Population dynamics refers to factors that affect the abundance and distribution of organisms within an ecosystem. These include abiotic factors like temperature and biotic factors like predator-prey interactions. Harvesting of resources can drive species to extinction if not managed sustainably. The distribution and abundance of species is important for sustainability. Factors like habitat characteristics, environmental conditions, and interactions between organisms influence where and how many individuals of a species exist in an area. Population size is determined by birth rates, death rates, immigration and emigration. Rapid population growth can occur when reproduction is high and limiting factors are absent.
The document discusses human population growth and population ecology. It provides age structure diagrams showing patterns of rapid, slow, zero, and negative population growth in different countries. Factors like births, deaths, and migration that determine population changes are identified. The document also discusses concepts like carrying capacity, logistic growth curves, r-selected and K-selected reproductive strategies, survivorship curves, ecological succession, and community structure.
This document discusses various factors that affect population size, including abiotic factors like temperature and biotic factors like predators. It describes different population characteristics such as range, density, growth rates, and survivorship curves. The main factors influencing population growth are discussed, such as carrying capacity, exponential versus logistic growth models, and density-dependent limiting factors that regulate population size.
This document discusses key concepts in population ecology, including population growth patterns, limiting factors, and spatial distributions. It covers exponential and logistic growth models and how populations are regulated by biotic and abiotic factors. Density-dependent limitations like predation, parasitism, and competition can stabilize populations at the carrying capacity. Spatial distributions can be clumped, uniform, or random depending on resource availability and social behaviors. Survivorship curves also describe mortality patterns in populations over time.
This document provides an overview of key concepts in population ecology. It discusses how populations are characterized by factors like range, dispersion, and density. Population size is determined by birth and death rates, which are influenced by both biotic and abiotic factors. Populations can grow exponentially without constraints but typically experience logistic growth limited by carrying capacity. Life history strategies like r-selected and K-selected influence patterns of reproduction and survivorship. Introduced invasive species sometimes grow rapidly without native controls.
Population ecology examines populations of species and how they change over time. Key features of populations include size, density, and dispersion. Population size is affected by birth and death rates. Density is measured as the number of individuals per unit area and is affected by factors like immigration, emigration, and environmental limits. Dispersion describes how organisms are spaced relative to each other, which can be clumped, even, or random. Populations can grow exponentially at first but eventually reach carrying capacity, where growth levels off due to environmental limits.
This document summarizes key concepts in population ecology, including factors that influence population size and distribution patterns. Populations can exhibit clumping, uniform, or random dispersion patterns depending on resource availability and other factors. A population's size is determined by the balance between birth and death rates, which are influenced by biotic potential and environmental resistance. Humans can impact ecosystems through activities like habitat degradation and overharvesting. Sustainable practices can be informed by principles seen in nature, such as nutrient recycling and population control.
Population dynamics refers to factors that affect the abundance and distribution of organisms within an ecosystem. These include abiotic factors like temperature and biotic factors like predator-prey interactions. Harvesting of resources can drive species to extinction if not managed sustainably. The distribution and abundance of species is important for sustainability. Factors like habitat characteristics, environmental conditions, and interactions between organisms influence where and how many individuals of a species exist in an area. Population size is determined by birth rates, death rates, immigration and emigration. Rapid population growth can occur when reproduction is high and limiting factors are absent.
The document discusses human population growth and population ecology. It provides age structure diagrams showing patterns of rapid, slow, zero, and negative population growth in different countries. Factors like births, deaths, and migration that determine population changes are identified. The document also discusses concepts like carrying capacity, logistic growth curves, r-selected and K-selected reproductive strategies, survivorship curves, ecological succession, and community structure.
This document discusses various factors that affect population size, including abiotic factors like temperature and biotic factors like predators. It describes different population characteristics such as range, density, growth rates, and survivorship curves. The main factors influencing population growth are discussed, such as carrying capacity, exponential versus logistic growth models, and density-dependent limiting factors that regulate population size.
This document discusses key concepts in population ecology, including population growth patterns, limiting factors, and spatial distributions. It covers exponential and logistic growth models and how populations are regulated by biotic and abiotic factors. Density-dependent limitations like predation, parasitism, and competition can stabilize populations at the carrying capacity. Spatial distributions can be clumped, uniform, or random depending on resource availability and social behaviors. Survivorship curves also describe mortality patterns in populations over time.
Population ecology examines how populations change over time based on birth, death, immigration, and emigration rates. Key concepts include:
- Populations have a density that can be influenced by density-dependent and density-independent factors.
- Natality is the birth rate and mortality is the death rate. These determine a population's growth rate.
- Populations can exhibit exponential or logistic growth patterns depending on available resources/carrying capacity.
- Reproductive strategies like r/K selection influence life history traits and population dynamics.
- Competition between species occupying the same niche frequently leads to competitive exclusion of one species.
This document provides an overview of key concepts in population ecology. It discusses how populations are characterized, including their range, dispersion patterns, and density. Factors that influence population size are examined, such as birth and death rates, immigration and emigration. Different reproductive strategies like r-selected and K-selected are described. Models of population growth, including exponential and logistic growth, are outlined. The impacts of limiting factors and carrying capacity on population growth are also summarized. Examples of human and invasive species population growth are provided.
This document discusses key concepts relating to populations and their growth patterns. It defines what a population is and describes characteristics like size, density, dispersion, and age distribution. Population growth can be exponential at first but will level off due to limiting factors like food or habitat availability. This carrying capacity can be modeled using the logistic growth equation. Real populations may exceed carrying capacity temporarily due to various biotic and abiotic factors. Species have evolved different life history strategies like r-selection and K-selection to cope with environmental variability. Population regulation can occur through density-dependent or density-independent controls.
World population dynamics can be understood by examining population distribution and growth rates over time. Population distribution is influenced by environmental factors and level of development. Places with large populations usually have favorable environments and are more developed, while places with few people often have hostile environments. Population growth is the result of birth rates, death rates, and migration. In the last 200 years, global population has experienced an unprecedented expansion due to improvements in medicine, sanitation and technology that reduced death rates even as birth rates remained high.
The document discusses various topics related to population dynamics, including:
1. Characteristics of populations such as population density, dispersion, growth, and carrying capacity.
2. Factors that influence population growth such as resources, reproductive strategies, and population cycles.
3. Models of human population growth including the demographic transition model.
4. Challenges facing developing countries in slowing population growth.
Population regulation results from a combination of density-dependent and density-independent factors that influence birth and death rates. Density-dependent factors like food supply, predation, and disease have effects that increase with population density, while density-independent factors like weather fluctuate independently of density. Various theories propose population equilibrium driven by these factors or non-equilibrium dynamics involving metapopulations and chaos. Small habitat loss can increase extinction risk through reduced population size and genetic problems or fragmentation leaving populations vulnerable to accidents.
A population is a group of organisms of the same species that live in the same area. Population size is determined by births, deaths, immigration, and emigration. If births and immigration exceed deaths and emigration, the population increases. Under ideal conditions without limitations, a population would experience exponential growth. However, limiting factors like resource availability typically cause logistic growth, where the population levels off at the carrying capacity of the environment.
Populations have characteristics like population size, density, age distribution, and dispersion that can change over time. A population's growth is determined by births and immigration minus deaths and emigration. Exponential growth occurs when births exceed deaths, but resources are ultimately limited by the environment's carrying capacity. Populations may exhibit r-selected or K-selected reproductive strategies depending on environmental pressures and resource availability.
Population dynamics is the study of changes in population sizes over time. Key aspects include population size, density, distribution, and growth trends. Population size is the number of individuals in an area, while density is the number per unit area. Mark-recapture sampling estimates population size by capturing, marking, and recapturing individuals. Demography analyzes population changes through birth rates, death rates, immigration, and emigration to determine growth rates. Populations can exhibit exponential or logistic growth patterns, with the latter limited by environmental carrying capacity. Many factors like resources, competition, and species interactions influence population growth.
Natural resource population dynamics examines how environmental factors influence changes in population numbers and composition over time. Bobwhite quail populations have severely declined over 50 years primarily due to loss of agricultural habitat. Quail need early succession habitat for nesting cover and brood ranges. Wildlife biologists track population changes of species of concern by counting calls and roadside surveys. Population dynamics are influenced by factors like density, birth rates, mortality rates, dispersal, age structure, sex ratios, and resource limitations.
This document discusses key concepts related to population dynamics including population, overpopulation, underpopulation, population distribution, factors affecting population change, and sustainable development. It defines key terms and provides examples to illustrate population density is highest in the riverine plains of Asia due to abundant resources, while arid, mountainous, and forested regions tend to have lower population density due to environmental challenges. Both overpopulation and underpopulation can have negative economic and social impacts.
Population ecology studies populations in relation to their environment. Key concepts include population density, dispersion patterns, growth rates, and factors influencing population size like competition and predation. Population size can be estimated using methods like mark-recapture. Human populations have grown exponentially but are slowing, with developing regions still experiencing most growth. Community structures involve interactions between species like competition, predation, herbivory and symbiosis. Ecological succession over time involves communities changing from pioneers to a climax.
This document discusses key concepts in population ecology, including population size, density, distribution, growth patterns, biotic potential, carrying capacity, r-selected and K-selected species, factors influencing population size, and examples of population growth curves showing exponential and logistic growth.
This document discusses population dynamics and factors that affect population sizes. It covers monitoring wild populations and how succession leads to climax plant communities. Density-independent factors like temperature and rainfall can influence populations. Density-dependent factors such as disease, food supply, predation, and competition also impact population change. Monitoring is important to understand wild population fluctuations over time. Succession describes the process by which pioneer species are replaced by later species until a climax community establishes.
The document discusses key concepts in population ecology including:
1) Ecology studies the interactions between organisms and their environment at different levels from populations to the biosphere.
2) Population structure is determined by density and distribution which can be affected by resource availability.
3) Population growth rates depend on birth rates, death rates, and immigration/emigration, with biotic potential representing the highest possible growth rate.
4) Survivorship curves illustrate how mortality varies with age in populations.
This document summarizes key concepts in population ecology:
- Populations initially grow exponentially as birth rates exceed death rates, but growth slows as resources diminish and competition increases, leveling off at the environment's carrying capacity.
- Population size is determined by the relative rates of birth, death, immigration and emigration.
- Limiting factors like resources and predation can regulate populations from the bottom-up or top-down.
- Estimating wild populations relies on sampling techniques since directly counting is impractical, such as capture-mark-recapture of fish.
Population ecology is the study of populations in relation to their environment. It includes influences on population density, distribution, age structure, and variations in population size. Key attributes of populations include birth rate, death rate, population density, sex ratio, and age distribution. Population growth occurs when birth rate exceeds death rate, though populations are limited by environmental carrying capacity. Populations interact through neutral, positive (e.g. mutualism), and negative (e.g. competition, predation) interactions that influence community structure.
Populations grow through births but their growth is limited by environmental factors like resources and space. Populations can experience exponential growth initially but eventually reach carrying capacity, where growth stabilizes. Human populations have grown rapidly due to improved living conditions and medicine, doubling approximately every 40-50 years, but resource limits may slow growth in the future.
The document discusses Thomas Malthus' theory of population growth and checks. Malthus theorized that population grows exponentially while food production increases arithmetically, leading to food shortages. He argued this imbalance would be corrected by positive checks like famine and disease or preventative checks like family planning. The document also provides population data for the Philippines, showing its population is projected to increase from around 105 million in 2017 to over 151 million in 2050.
The document discusses factors that influence population growth rates, including birth rates, death rates, sex ratios, age distributions, immigration, and emigration. It describes exponential and logistic population growth curves and how populations level off at the carrying capacity. Key life history traits like age at maturity, number of offspring, and lifespan vary widely between species like salmon, elephants, and mice. The document aims to explain population ecology concepts like survivorship curves, population density, population cycling, environmental resistance, and carrying capacity.
Population dynamics refers to the characteristics and changes in populations over time. Key factors that influence population size include birth rates, death rates, population density, age structure, and dispersion within a habitat. Under ideal conditions with no environmental constraints, populations would experience exponential growth due to high biotic potential. However, in reality populations reach an equilibrium known as carrying capacity, where growth levels off due to limiting factors like competition for resources and predation.
Population ecology examines how populations change over time based on birth, death, immigration, and emigration rates. Key concepts include:
- Populations have a density that can be influenced by density-dependent and density-independent factors.
- Natality is the birth rate and mortality is the death rate. These determine a population's growth rate.
- Populations can exhibit exponential or logistic growth patterns depending on available resources/carrying capacity.
- Reproductive strategies like r/K selection influence life history traits and population dynamics.
- Competition between species occupying the same niche frequently leads to competitive exclusion of one species.
This document provides an overview of key concepts in population ecology. It discusses how populations are characterized, including their range, dispersion patterns, and density. Factors that influence population size are examined, such as birth and death rates, immigration and emigration. Different reproductive strategies like r-selected and K-selected are described. Models of population growth, including exponential and logistic growth, are outlined. The impacts of limiting factors and carrying capacity on population growth are also summarized. Examples of human and invasive species population growth are provided.
This document discusses key concepts relating to populations and their growth patterns. It defines what a population is and describes characteristics like size, density, dispersion, and age distribution. Population growth can be exponential at first but will level off due to limiting factors like food or habitat availability. This carrying capacity can be modeled using the logistic growth equation. Real populations may exceed carrying capacity temporarily due to various biotic and abiotic factors. Species have evolved different life history strategies like r-selection and K-selection to cope with environmental variability. Population regulation can occur through density-dependent or density-independent controls.
World population dynamics can be understood by examining population distribution and growth rates over time. Population distribution is influenced by environmental factors and level of development. Places with large populations usually have favorable environments and are more developed, while places with few people often have hostile environments. Population growth is the result of birth rates, death rates, and migration. In the last 200 years, global population has experienced an unprecedented expansion due to improvements in medicine, sanitation and technology that reduced death rates even as birth rates remained high.
The document discusses various topics related to population dynamics, including:
1. Characteristics of populations such as population density, dispersion, growth, and carrying capacity.
2. Factors that influence population growth such as resources, reproductive strategies, and population cycles.
3. Models of human population growth including the demographic transition model.
4. Challenges facing developing countries in slowing population growth.
Population regulation results from a combination of density-dependent and density-independent factors that influence birth and death rates. Density-dependent factors like food supply, predation, and disease have effects that increase with population density, while density-independent factors like weather fluctuate independently of density. Various theories propose population equilibrium driven by these factors or non-equilibrium dynamics involving metapopulations and chaos. Small habitat loss can increase extinction risk through reduced population size and genetic problems or fragmentation leaving populations vulnerable to accidents.
A population is a group of organisms of the same species that live in the same area. Population size is determined by births, deaths, immigration, and emigration. If births and immigration exceed deaths and emigration, the population increases. Under ideal conditions without limitations, a population would experience exponential growth. However, limiting factors like resource availability typically cause logistic growth, where the population levels off at the carrying capacity of the environment.
Populations have characteristics like population size, density, age distribution, and dispersion that can change over time. A population's growth is determined by births and immigration minus deaths and emigration. Exponential growth occurs when births exceed deaths, but resources are ultimately limited by the environment's carrying capacity. Populations may exhibit r-selected or K-selected reproductive strategies depending on environmental pressures and resource availability.
Population dynamics is the study of changes in population sizes over time. Key aspects include population size, density, distribution, and growth trends. Population size is the number of individuals in an area, while density is the number per unit area. Mark-recapture sampling estimates population size by capturing, marking, and recapturing individuals. Demography analyzes population changes through birth rates, death rates, immigration, and emigration to determine growth rates. Populations can exhibit exponential or logistic growth patterns, with the latter limited by environmental carrying capacity. Many factors like resources, competition, and species interactions influence population growth.
Natural resource population dynamics examines how environmental factors influence changes in population numbers and composition over time. Bobwhite quail populations have severely declined over 50 years primarily due to loss of agricultural habitat. Quail need early succession habitat for nesting cover and brood ranges. Wildlife biologists track population changes of species of concern by counting calls and roadside surveys. Population dynamics are influenced by factors like density, birth rates, mortality rates, dispersal, age structure, sex ratios, and resource limitations.
This document discusses key concepts related to population dynamics including population, overpopulation, underpopulation, population distribution, factors affecting population change, and sustainable development. It defines key terms and provides examples to illustrate population density is highest in the riverine plains of Asia due to abundant resources, while arid, mountainous, and forested regions tend to have lower population density due to environmental challenges. Both overpopulation and underpopulation can have negative economic and social impacts.
Population ecology studies populations in relation to their environment. Key concepts include population density, dispersion patterns, growth rates, and factors influencing population size like competition and predation. Population size can be estimated using methods like mark-recapture. Human populations have grown exponentially but are slowing, with developing regions still experiencing most growth. Community structures involve interactions between species like competition, predation, herbivory and symbiosis. Ecological succession over time involves communities changing from pioneers to a climax.
This document discusses key concepts in population ecology, including population size, density, distribution, growth patterns, biotic potential, carrying capacity, r-selected and K-selected species, factors influencing population size, and examples of population growth curves showing exponential and logistic growth.
This document discusses population dynamics and factors that affect population sizes. It covers monitoring wild populations and how succession leads to climax plant communities. Density-independent factors like temperature and rainfall can influence populations. Density-dependent factors such as disease, food supply, predation, and competition also impact population change. Monitoring is important to understand wild population fluctuations over time. Succession describes the process by which pioneer species are replaced by later species until a climax community establishes.
The document discusses key concepts in population ecology including:
1) Ecology studies the interactions between organisms and their environment at different levels from populations to the biosphere.
2) Population structure is determined by density and distribution which can be affected by resource availability.
3) Population growth rates depend on birth rates, death rates, and immigration/emigration, with biotic potential representing the highest possible growth rate.
4) Survivorship curves illustrate how mortality varies with age in populations.
This document summarizes key concepts in population ecology:
- Populations initially grow exponentially as birth rates exceed death rates, but growth slows as resources diminish and competition increases, leveling off at the environment's carrying capacity.
- Population size is determined by the relative rates of birth, death, immigration and emigration.
- Limiting factors like resources and predation can regulate populations from the bottom-up or top-down.
- Estimating wild populations relies on sampling techniques since directly counting is impractical, such as capture-mark-recapture of fish.
Population ecology is the study of populations in relation to their environment. It includes influences on population density, distribution, age structure, and variations in population size. Key attributes of populations include birth rate, death rate, population density, sex ratio, and age distribution. Population growth occurs when birth rate exceeds death rate, though populations are limited by environmental carrying capacity. Populations interact through neutral, positive (e.g. mutualism), and negative (e.g. competition, predation) interactions that influence community structure.
Populations grow through births but their growth is limited by environmental factors like resources and space. Populations can experience exponential growth initially but eventually reach carrying capacity, where growth stabilizes. Human populations have grown rapidly due to improved living conditions and medicine, doubling approximately every 40-50 years, but resource limits may slow growth in the future.
The document discusses Thomas Malthus' theory of population growth and checks. Malthus theorized that population grows exponentially while food production increases arithmetically, leading to food shortages. He argued this imbalance would be corrected by positive checks like famine and disease or preventative checks like family planning. The document also provides population data for the Philippines, showing its population is projected to increase from around 105 million in 2017 to over 151 million in 2050.
The document discusses factors that influence population growth rates, including birth rates, death rates, sex ratios, age distributions, immigration, and emigration. It describes exponential and logistic population growth curves and how populations level off at the carrying capacity. Key life history traits like age at maturity, number of offspring, and lifespan vary widely between species like salmon, elephants, and mice. The document aims to explain population ecology concepts like survivorship curves, population density, population cycling, environmental resistance, and carrying capacity.
Population dynamics refers to the characteristics and changes in populations over time. Key factors that influence population size include birth rates, death rates, population density, age structure, and dispersion within a habitat. Under ideal conditions with no environmental constraints, populations would experience exponential growth due to high biotic potential. However, in reality populations reach an equilibrium known as carrying capacity, where growth levels off due to limiting factors like competition for resources and predation.
Population dynamics refers to the characteristics and changes in populations over time. Key factors that influence population size include birth rates, death rates, population density, age structure, and dispersion within a habitat. Under ideal conditions, populations can grow exponentially according to their biotic potential. However, environmental resistance factors like limited resources typically cause populations to level off at the carrying capacity of their environment, resulting in logistic growth curves. Conservation biology aims to protect biodiversity and ecosystems from threats like habitat loss and fragmentation caused by human activities.
Deocareza population ecology-1231427563650176-1 (1)carlo2307
This document discusses population ecology and dynamics. It begins by defining population ecology as the study of individual species in relation to their environment. It then discusses population viability analysis, which assesses extinction risk by combining species characteristics and environmental variability. The document goes on to discuss major population characteristics like distribution, size, age structure, and density. It also covers factors that affect population size, like birth and death rates, as well as resources and competition that can limit growth. Finally, it discusses life tables and survivorship curves that are used to monitor population trends over time.
This document discusses population ecology and dynamics. It begins by defining population ecology as the study of individual species in relation to their environment. It then discusses population viability analysis, which assesses extinction risk by combining species characteristics and environmental variability. The document goes on to discuss major population characteristics like distribution, size, age structure, and density. It also covers factors that affect population size, like birth and death rates, as well as resources and competition that can limit growth. Finally, it discusses life tables and survivorship curves that are used to monitor population trends over time.
The document discusses various topics related to population biology, including:
1) Factors that affect population growth rates such as births, deaths, immigration and emigration. Population growth can be exponential or logistic depending on resource availability.
2) Population regulation through density-dependent and density-independent factors such as competition, disease, and environmental conditions.
3) Conservation biology concepts including minimum viable populations, genetic diversity, metapopulations, and population viability analysis.
The document discusses key topics in population ecology, including characteristics of populations such as population density, growth rate, age structure, survivorship curves, and limiting factors. It describes different patterns of population growth, such as exponential and logistic growth, and how populations are regulated by carrying capacity. Reproductive strategies of r-selected and K-selected species are compared. The document also provides highlights from the 2015 Philippines Population Census, including population size, growth rates by region, and demographic trends.
The document discusses several key concepts in population biology including:
1) Factors that affect population growth such as biotic potential, birth and death rates, immigration and emigration.
2) Models for describing population growth patterns including exponential, logistic, r-selected and K-selected species.
3) Factors that regulate population growth including density-dependent and density-independent factors as well as abiotic and biotic influences.
4) Conservation biology concepts such as minimum viable population size, genetic diversity, and metapopulation structure.
This document summarizes key concepts in population ecology, including:
1) Population density refers to the number of individuals per unit area, while distribution refers to where individuals are located. Limiting factors restrict population size and distribution.
2) Intrinsic rate of natural increase describes population growth based on birth and death rates. Exponential growth occurs with unlimited resources, while logistic growth slows as resources diminish.
3) Life history patterns vary based on environmental stability - r-selected species thrive in unstable environments with many offspring, while K-selected species in stable environments have few offspring and parental care.
This document summarizes key concepts in population ecology, including:
1) Population density refers to the number of individuals per unit area, while distribution refers to where individuals are located. Limiting factors restrict population size and distribution.
2) Intrinsic rate of natural increase describes population growth based on birth and death rates. Exponential growth occurs with unlimited resources, while logistic growth slows as resources diminish.
3) Life history patterns vary based on environmental stability - r-selected species thrive in unstable environments with many offspring, while K-selected species in stable environments have few offspring and parental care.
This document discusses key concepts in population ecology, including population size, density, distribution, growth patterns, biotic potential, carrying capacity, r-selected and K-selected species, environmental resistance, and predator-prey cycles. It provides examples and explanations of exponential and logistic growth curves, and compares characteristics of r-selected and K-selected species.
1. The document discusses various levels of biological organization from the ecosystem level down to the molecular level, providing examples like the eucalyptus forest ecosystem and the flying fox population.
2. It then focuses on population ecology, defining key population features like size, density, dispersion, growth rates, and factors that influence population growth like immigration, emigration, birth rates and death rates.
3. Models of population growth are discussed, including exponential and logistic growth curves, and the concept of carrying capacity is introduced as the maximum population size supported by available resources.
This document discusses key concepts in population ecology, including the five characteristics of a population: geographic distribution, density, dispersion, growth rate, and age structure. It provides examples and explanations of each characteristic. Geographic distribution describes the area inhabited by a population. Density is the number of individuals per unit area. Dispersion describes the spatial distribution of individuals as either clumped, even, or random. Growth rate measures changes in population size over time. Age structure diagrams show population breakdown by age and sex.
Population projection is a prediction of future population changes based on current trends of mortality, fertility and migration. It considers the present age-gender structure and applies current rates to predict future populations.
Population momentum refers to the continued growth of a population even after fertility rates fall to the replacement level. This is because there is still a large number of people in the reproductive age range who will have children, continuing population growth in the short term until these groups age.
This document discusses key concepts in population ecology, including:
- Population is defined as all individuals of a species living in an area. Demography is the statistical study of populations.
- Population size, density, distribution, and changes over time are important to study. Populations can experience exponential or logistic growth depending on available resources.
- Survivorship curves (Type I, II, III) describe mortality patterns. Reproductive strategies also influence population growth.
- Human population growth has increased due to improved health and technology, though uncontrolled growth risks environmental damage.
This document discusses key concepts in population ecology. It defines what a population is and explains that populations can change over time due to various factors. It provides the example of sea otters, kelp, and sea urchins to illustrate how the removal and reintroduction of sea otters can impact the populations of kelp and sea urchins. The document also outlines important population characteristics like geographic distribution, density, and growth rate. It discusses factors that affect population size such as births, deaths, immigration and emigration. Finally, it explains concepts like exponential and logistic growth, carrying capacity, limiting factors, and boom-and-bust growth cycles.
The document discusses various concepts related to population ecology, including patterns of dispersion, survivorship patterns, life history strategies, factors limiting population growth, historical and projected changes in human population size, and age structure profiles of growing, stable, and declining populations. Examples and figures are provided to illustrate key points about how environmental conditions and density-dependent factors influence population dynamics over time.
The document discusses several topics related to population biology and human population growth, including:
1) Factors that influence population growth such as birth rates, death rates, and environmental limits. Populations exhibit either rapid exponential growth or slow steady growth depending on these factors.
2) Techniques scientists use to estimate population sizes such as sampling and mark-recapture when it is difficult to count all individuals.
3) Human population growth has increased rapidly over the past 150 years from 1 billion to over 7 billion currently due to declining death rates from improvements in health, education, and sanitation.
This document provides a review for a Physical Science final exam, outlining 9 competencies covered on the exam. It includes 75 multiple choice and short answer questions testing understanding of concepts in motion, waves, electricity, thermodynamics, atomic structure, nuclear processes, bonding, and acids/bases. Sample questions assess knowledge of the scientific method, graphing, Newton's laws, energy transformations, electromagnetic radiation, the periodic table, nuclear reactions, and chemical equations.
This document provides 42 multi-part physics problems involving Newton's laws of motion. The problems cover concepts such as force, mass, acceleration, weight, and their relationships. Some sample answers are provided. The problems involve calculating unknown values like force, mass, or acceleration given information about real-world scenarios involving objects in motion or at rest under the influence of various forces.
1. This document discusses different types of waves including transverse, longitudinal, and electromagnetic waves. It defines key wave properties such as amplitude, wavelength, frequency, period, and wave speed.
2. Frequency is defined as the number of vibrations per second, measured in Hertz (Hz). Period is the time for one full vibration. Frequency and period are inversely related.
3. Examples are provided to demonstrate calculating wave properties like frequency, period, wavelength, and wave speed from information given about the wave.
This document discusses electrical power and energy. It explains that power is calculated as current multiplied by voltage, and is measured in watts. It asks the reader to calculate the power needed to operate a clock radio drawing 0.05 amps from a household circuit. The document also explains that electrical energy is provided by power companies and sold to homeowners in units of kilowatt-hours, which is 1000 watts delivered for one hour. It provides an example of calculating the electrical energy used and cost for a 1200W toaster oven used for 15 minutes.
This document explains the differences between alternating current (AC) and direct current (DC). It defines AC as an electric current that periodically reverses direction and changes its magnitude continuously with time in contrast to DC, which flows in one direction. The document also outlines the key characteristics of series and parallel electric circuits. Series circuits have the same current flowing through all elements and the total voltage is divided among the elements. Parallel circuits have the same voltage across each element and the total current is the sum of the currents in the individual branches. The document concludes by noting that fuses are used to prevent circuit overloading by melting and breaking the circuit if too much current passes through.
This document provides an Ohm's Law worksheet with 6 practice problems calculating voltage, current, and resistance using the equations: I = V/R, R = V/I, and V = IR. Students are asked to use these equations to find the missing value in each circuit scenario, such as calculating the voltage applied to a light bulb with a known current and resistance.
This document contains a worksheet on Ohm's Law with 14 problems. The worksheet provides the three forms of Ohm's Law and asks students to calculate values like voltage, current, and resistance using circuits with resistors and batteries. Students are asked to determine unknown values, total resistances, and currents in various circuit diagrams applying the relationships defined by Ohm's Law.
This document provides an Ohm's Law worksheet with 6 practice problems calculating voltage, current, and resistance using the equations: I = V/R, R = V/I, and V = IR. Students are asked to use these equations to find the missing value in each circuit scenario, such as calculating the voltage applied to a light bulb with a known current and resistance.
This document discusses resistance and Ohm's Law. It describes the key parts of Ohm's Law including volts, amps, and resistance. It also explains how to calculate an unknown value using two known values and Ohm's Law. Examples are provided to demonstrate calculating current and resistance using Ohm's Law. The document also discusses how resistance affects current and electric shock, and provides examples of calculating current through the body at different resistances and voltages.
Static electricity and electrical currantssbarkanic
This document defines static electricity and current electricity. It explains that static electricity is caused by an imbalance of electric charges, usually through rubbing materials together, while current electricity involves the controlled flow of electrons. It distinguishes conductors that allow electron flow from insulators that do not, and describes how static charges build up and arc in lightning.
This document covers acids and bases, including definitions, properties, examples and the pH scale. It also discusses acid rain, its effects and causes. For radioactivity, it defines different types and compares the strong force to the electric force in alpha and beta equations. It explains transmutation, half-life, fission and chain reactions. Additionally, it outlines nuclear power plants, how they create electricity from fission, reasons for past meltdowns and pros and cons of nuclear power. Finally, it addresses the big bang theory, evidence supporting it, the potential end of the universe, star formation, star types and life cycles.
This document discusses chemical equations and reactions. It explains that chemical equations are used to represent chemical reactions, and that they consist of reactants on the left side of the arrow yielding products on the right. It also describes how to balance chemical equations by adjusting coefficients so that the same number of each type of atom is on both sides of the equation. Balancing chemical equations ensures conservation of mass during chemical reactions.
Naming and writing compounds and moleculessbarkanic
This document provides instructions for writing formulas and naming ionic compounds, covalent molecules, and polyatomic ions. It explains that for ionic compounds, you write the symbols of the ions and use the crossover method to determine subscripts before naming the compound by writing the cation name followed by the anion name with "ide." For covalent molecules, Greek prefixes indicate subscripts and the name is written by specifying each element followed by the number of atoms. Polyatomic ions are also named and included in ionic compounds by looking up their formula and charge. Examples and practice problems are provided to demonstrate the process.
1) The document provides instructions for drawing Lewis structures to show ionic and covalent bonding between various elements. Students are asked to draw Lewis structures for pairs of elements, and indicate electron transfers or sharing to write chemical formulas. 2) For ionic bonds, students should draw Lewis structures, arrows to show electron transfer, charges for each ion, and chemical formulas. 3) For covalent bonds, the instructions are to draw Lewis structures, circles around shared electrons, bond structures, and chemical formulas.
The document discusses atomic spectra and the Bohr model. It explains that atoms can absorb and emit light at specific frequencies, and this atomic spectrum acts as a fingerprint that can be used to identify elements. The Bohr model describes electrons occupying different energy shells around the nucleus, and electrons absorbing and emitting energy by jumping between shells and releasing light. The document also briefly mentions flame tests and spectroscopes as methods to observe atomic spectra.
Ernest Rutherford (1871-1937) was a notable British physicist and chemist who made seminal contributions to the development of the modern atomic model. Through his gold foil experiment in 1911, Rutherford was able to formulate the Rutherford model of the atom, which established that atoms have a small, positively charged nucleus surrounded by low-mass electrons. For this breakthrough discovery, Rutherford received numerous honors including the Nobel Prize in Chemistry in 1908. His work fundamentally changed scientific understanding of atomic structure.
Lise Meitner was an Austrian/German physicist born in 1878 who made significant contributions to nuclear physics. She received her doctorate in 1905 as the second woman to earn a PhD from the University of Vienna. In 1938, Meitner, Otto Hahn, and Fritz Strassmann discovered nuclear fission when bombarding uranium with neutrons. This splitting of uranium atoms led to additional neutrons and the potential for an explosive chain reaction. Sadly, her discovery was later used in 1945 for the atomic bomb dropped on Hiroshima. Meitner received several honors for her work, including the Max Planck medal in 1949.
Murray Gell-Mann was born in 1929 and is still living. He graduated valedictorian from Columbia Grammar School and attended Yale University at age 15. Gell-Mann won the 1969 Nobel Prize in Physics. In 1964, he discovered the quark, which makes up protons and neutrons in the nucleus. Quarks have never been isolated due to their small size of 10-15 mm. Gell-Mann is also interested in activities like bird watching and collecting antiques.
Democritus was a Greek philosopher born around 460-457 BC in Abdera, Thrace. He developed the first atomic theory, proposing that all matter is made up of indivisible atoms moving through empty space. Democritus believed that atoms were the fundamental building blocks of the natural world and that their behavior determined natural phenomena. He and his mentor Leucippus are considered the founders of atomic theory. Democritus was highly respected in his lifetime for making discoveries and predictions that were later proven true.
In our second session, we shall learn all about the main features and fundamentals of UiPath Studio that enable us to use the building blocks for any automation project.
📕 Detailed agenda:
Variables and Datatypes
Workflow Layouts
Arguments
Control Flows and Loops
Conditional Statements
💻 Extra training through UiPath Academy:
Variables, Constants, and Arguments in Studio
Control Flow in Studio
What is an RPA CoE? Session 2 – CoE RolesDianaGray10
In this session, we will review the players involved in the CoE and how each role impacts opportunities.
Topics covered:
• What roles are essential?
• What place in the automation journey does each role play?
Speaker:
Chris Bolin, Senior Intelligent Automation Architect Anika Systems
Introduction of Cybersecurity with OSS at Code Europe 2024Hiroshi SHIBATA
I develop the Ruby programming language, RubyGems, and Bundler, which are package managers for Ruby. Today, I will introduce how to enhance the security of your application using open-source software (OSS) examples from Ruby and RubyGems.
The first topic is CVE (Common Vulnerabilities and Exposures). I have published CVEs many times. But what exactly is a CVE? I'll provide a basic understanding of CVEs and explain how to detect and handle vulnerabilities in OSS.
Next, let's discuss package managers. Package managers play a critical role in the OSS ecosystem. I'll explain how to manage library dependencies in your application.
I'll share insights into how the Ruby and RubyGems core team works to keep our ecosystem safe. By the end of this talk, you'll have a better understanding of how to safeguard your code.
Freshworks Rethinks NoSQL for Rapid Scaling & Cost-EfficiencyScyllaDB
Freshworks creates AI-boosted business software that helps employees work more efficiently and effectively. Managing data across multiple RDBMS and NoSQL databases was already a challenge at their current scale. To prepare for 10X growth, they knew it was time to rethink their database strategy. Learn how they architected a solution that would simplify scaling while keeping costs under control.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/temporal-event-neural-networks-a-more-efficient-alternative-to-the-transformer-a-presentation-from-brainchip/
Chris Jones, Director of Product Management at BrainChip , presents the “Temporal Event Neural Networks: A More Efficient Alternative to the Transformer” tutorial at the May 2024 Embedded Vision Summit.
The expansion of AI services necessitates enhanced computational capabilities on edge devices. Temporal Event Neural Networks (TENNs), developed by BrainChip, represent a novel and highly efficient state-space network. TENNs demonstrate exceptional proficiency in handling multi-dimensional streaming data, facilitating advancements in object detection, action recognition, speech enhancement and language model/sequence generation. Through the utilization of polynomial-based continuous convolutions, TENNs streamline models, expedite training processes and significantly diminish memory requirements, achieving notable reductions of up to 50x in parameters and 5,000x in energy consumption compared to prevailing methodologies like transformers.
Integration with BrainChip’s Akida neuromorphic hardware IP further enhances TENNs’ capabilities, enabling the realization of highly capable, portable and passively cooled edge devices. This presentation delves into the technical innovations underlying TENNs, presents real-world benchmarks, and elucidates how this cutting-edge approach is positioned to revolutionize edge AI across diverse applications.
Main news related to the CCS TSI 2023 (2023/1695)Jakub Marek
An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .
"Scaling RAG Applications to serve millions of users", Kevin GoedeckeFwdays
How we managed to grow and scale a RAG application from zero to thousands of users in 7 months. Lessons from technical challenges around managing high load for LLMs, RAGs and Vector databases.
What is an RPA CoE? Session 1 – CoE VisionDianaGray10
In the first session, we will review the organization's vision and how this has an impact on the COE Structure.
Topics covered:
• The role of a steering committee
• How do the organization’s priorities determine CoE Structure?
Speaker:
Chris Bolin, Senior Intelligent Automation Architect Anika Systems
QA or the Highway - Component Testing: Bridging the gap between frontend appl...zjhamm304
These are the slides for the presentation, "Component Testing: Bridging the gap between frontend applications" that was presented at QA or the Highway 2024 in Columbus, OH by Zachary Hamm.
Northern Engraving | Nameplate Manufacturing Process - 2024Northern Engraving
Manufacturing custom quality metal nameplates and badges involves several standard operations. Processes include sheet prep, lithography, screening, coating, punch press and inspection. All decoration is completed in the flat sheet with adhesive and tooling operations following. The possibilities for creating unique durable nameplates are endless. How will you create your brand identity? We can help!
High performance Serverless Java on AWS- GoTo Amsterdam 2024Vadym Kazulkin
Java is for many years one of the most popular programming languages, but it used to have hard times in the Serverless community. Java is known for its high cold start times and high memory footprint, comparing to other programming languages like Node.js and Python. In this talk I'll look at the general best practices and techniques we can use to decrease memory consumption, cold start times for Java Serverless development on AWS including GraalVM (Native Image) and AWS own offering SnapStart based on Firecracker microVM snapshot and restore and CRaC (Coordinated Restore at Checkpoint) runtime hooks. I'll also provide a lot of benchmarking on Lambda functions trying out various deployment package sizes, Lambda memory settings, Java compilation options and HTTP (a)synchronous clients and measure their impact on cold and warm start times.
"Frontline Battles with DDoS: Best practices and Lessons Learned", Igor IvaniukFwdays
At this talk we will discuss DDoS protection tools and best practices, discuss network architectures and what AWS has to offer. Also, we will look into one of the largest DDoS attacks on Ukrainian infrastructure that happened in February 2022. We'll see, what techniques helped to keep the web resources available for Ukrainians and how AWS improved DDoS protection for all customers based on Ukraine experience
inQuba Webinar Mastering Customer Journey Management with Dr Graham HillLizaNolte
HERE IS YOUR WEBINAR CONTENT! 'Mastering Customer Journey Management with Dr. Graham Hill'. We hope you find the webinar recording both insightful and enjoyable.
In this webinar, we explored essential aspects of Customer Journey Management and personalization. Here’s a summary of the key insights and topics discussed:
Key Takeaways:
Understanding the Customer Journey: Dr. Hill emphasized the importance of mapping and understanding the complete customer journey to identify touchpoints and opportunities for improvement.
Personalization Strategies: We discussed how to leverage data and insights to create personalized experiences that resonate with customers.
Technology Integration: Insights were shared on how inQuba’s advanced technology can streamline customer interactions and drive operational efficiency.
Essentials of Automations: Exploring Attributes & Automation ParametersSafe Software
Building automations in FME Flow can save time, money, and help businesses scale by eliminating data silos and providing data to stakeholders in real-time. One essential component to orchestrating complex automations is the use of attributes & automation parameters (both formerly known as “keys”). In fact, it’s unlikely you’ll ever build an Automation without using these components, but what exactly are they?
Attributes & automation parameters enable the automation author to pass data values from one automation component to the next. During this webinar, our FME Flow Specialists will cover leveraging the three types of these output attributes & parameters in FME Flow: Event, Custom, and Automation. As a bonus, they’ll also be making use of the Split-Merge Block functionality.
You’ll leave this webinar with a better understanding of how to maximize the potential of automations by making use of attributes & automation parameters, with the ultimate goal of setting your enterprise integration workflows up on autopilot.
2. AP Biology
Life takes place in populations
Population
group of individuals of same species in
same area at same time
rely on same
resources
interact
interbreed
rely on same
resources
interact
interbreed
Population Ecology: What factors affect a population?Population Ecology: What factors affect a population?
3. AP Biology
Why Population Ecology?
Scientific goal
understanding the factors that influence the
size of populations
general principles
specific cases
Practical goal
management of populations
increase population size
endangered species
decrease population size
pests
maintain population size
fisheries management
maintain & maximize sustained yield
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
4. AP Biology
Abiotic factors
sunlight & temperature
precipitation / water
soil / nutrients
Biotic factors
other living organisms
prey (food)
competitors
predators, parasites,
disease
Intrinsic factors
adaptations
Factors that affect Population Size
5. AP Biology
Characterizing a Population
Describing a population
population range
pattern of spacing
density
size of population
1937
1943
1951
1958
1961
1960
19651964
1966 1970
1970
1956
Immigration
from Africa
~1900
Equator
range
density
6. AP Biology
Population Range
Geographical limitations
abiotic & biotic factors
temperature, rainfall, food, predators, etc.
habitat
adaptations to
polar biome
adaptations to
polar biome
adaptations to
rainforest biome
adaptations to
rainforest biome
7. AP Biology
Changes in range
Range expansions & contractions
changing environment
Woodlands
Grassland, chaparral,
and desert scrub
15,000 years ago
glacial periodAlpine tundra
Spruce-fir forests
Mixed conifer forest
0 km
2 km
3 km
1 km
Elevation(km)
PresentAlpine tundra
Spruce-fir forests
Mixed conifer forest
Woodlands
Grassland,
chaparral, and
desert scrub
aspen oak, maple white birch sequoia
result of competitionresult of competition
8. AP Biology
At risk populations
Endangered species
limitations to range / habitat
places species at risk
Socorro
isopod
Devil’s hole
pupfish
Iriomote cat
Northern white rhinoceros
New Guinea
tree
kangaroo
Iiwi
Hawaiian
bird
Catalina
Island
mahogany
tree
9. AP Biology
Population Spacing
Dispersal patterns within a population
uniform
random
clumped
Provides insight into the
environmental associations
& social interactions of
individuals in population
Provides insight into the
environmental associations
& social interactions of
individuals in population
12. AP Biology
Population Size
Changes to
population size
adding & removing
individuals from a
population
birth
death
immigration
emigration
13. AP Biology
Population growth rates
Factors affecting population growth rate
sex ratio
how many females vs. males?
generation time
at what age do females reproduce?
age structure
how females at reproductive age in cohort?
14. AP Biology
Life tableLife table
Demography
Factors that affect growth & decline of
populations
vital statistics & how they change over time
Why do teenage boys pay high car insurance rates?Why do teenage boys pay high car insurance rates?
females males
What adaptations have
led to this difference
in male vs. female
mortality?
15. AP Biology
Survivorship curves
Graphic representation of life table
Belding ground squirrel
The relatively straight lines of the plots indicate relatively constant
rates of death; however, males have a lower survival rate overall
than females.
The relatively straight lines of the plots indicate relatively constant
rates of death; however, males have a lower survival rate overall
than females.
16. AP Biology
Age structure
Relative number of individuals of each age
What do these data imply about population growth
in these countries?
17. AP Biology
Survivorship curves
Generalized strategies
What do these graphs
tell about survival &
strategy of a species?
What do these graphs
tell about survival &
strategy of a species?
0 25
1000
100
Human
(type I)
Hydra
(type II)
Oyster
(type III)
10
1
50
Percent of maximum life span
10075
Survivalperthousand
I. High death rate in
post-reproductive
years
I. High death rate in
post-reproductive
years
II. Constant mortality
rate throughout life
span
II. Constant mortality
rate throughout life
span
III. Very high early
mortality but the
few survivors then
live long (stay
reproductive)
III. Very high early
mortality but the
few survivors then
live long (stay
reproductive)
18. AP Biology
Trade-offs: survival vs. reproduction
The cost of reproduction
increase reproduction may decrease survival
age at first reproduction
investment per offspring
number of reproductive cycles per lifetime
Natural selection
favors a life
history that
maximizes lifetime
reproductive
success
Natural selection
favors a life
history that
maximizes lifetime
reproductive
success
20. AP Biology
Reproductive strategies
K-selected
late reproduction
few offspring
invest a lot in raising offspring
primates
coconut
r-selected
early reproduction
many offspring
little parental care
insects
many plants
K-selected
r-selected
21. AP Biology
Trade offs
Number & size of offspring
vs.
Survival of offspring or parent
Number & size of offspring
vs.
Survival of offspring or parent
r-selected
K-selected
“Of course, long before you mature,
most of you will be eaten.”
22. AP Biology
Life strategies & survivorship curves
0 25
1000
100
Human
(type I)
Hydra
(type II)
Oyster
(type III)
10
1
50
Percent of maximum life span
10075
Survivalperthousand
K-selection
r-selection
23. AP Biology
Population growth
change in population = births – deaths
Exponential model (ideal conditions)
dN = riN
dt
N = # of individuals
r = rate of growth
ri = intrinsic rate
t = time
d = rate of change
growth increasing at constant rate
intrinsic rate =
maximum rate of growth
every pair has
4 offspring
every pair has
4 offspring
every pair has
3 offspring
every pair has
3 offspring
24. AP Biology
African elephant
protected from hunting
Whooping crane
coming back from near extinction
Exponential growth rate
Characteristic of populations without
limiting factors
introduced to a new environment or rebounding
from a catastrophe
25. AP Biology
Regulation of population size
Limiting factors
density dependent
competition: food, mates,
nesting sites
predators, parasites,
pathogens
density independent
abiotic factors
sunlight (energy)
temperature
rainfall
swarming locusts
marking territory
= competition
competition for nesting sites
26. AP Biology
Introduced species
Non-native species
transplanted populations grow
exponentially in new area
out-compete native species
loss of natural controls
lack of predators, parasites,
competitors
reduce diversity
examples
African honeybee
gypsy moth
zebra mussel
purple loosestrife
kudzu
gypsy moth
27. AP Biology
Zebra mussel
ecological & economic damage
~2 months
reduces diversity
loss of food & nesting sites
for animals
economic damage
reduces diversity
loss of food & nesting sites
for animals
economic damage
28. AP Biology
Purple loosestrife
19681968 19781978
reduces diversity
loss of food & nesting sites
for animals
reduces diversity
loss of food & nesting sites
for animals
29. AP Biology
K =
carrying
capacity
K =
carrying
capacity
Logistic rate of growth
Can populations continue to grow
exponentially? Of course not!Of course not!
effect of
natural controls
effect of
natural controls
no natural controlsno natural controls
What happens as
N approaches K?
30. AP Biology
500
400
300
200
100
0
200 10 30 5040 60
Time (days)
Numberofcladocerans
(per200ml)
Maximum
population size
that environment
can support with
no degradation
of habitat
varies with
changes in
resources
Time (years)
1915 1925 1935 1945
10
8
6
4
2
0
Numberofbreedingmale
furseals(thousands)
Carrying capacity
What’s going
on with the
plankton?
31. AP Biology
Changes in Carrying Capacity
Population cycles
predator – prey
interactions
At what
population level is the
carrying capacity?
KK
KK
32. AP Biology
Human population growth
What factors have contributed to
this exponential growth pattern?
What factors have contributed to
this exponential growth pattern?
1650→500 million
2005→6 billion
Industrial Revolution
Significant advances
in medicine through
science and technology
Bubonic plague "Black Death"
Population of…
China: 1.3 billion
India: 1.1 billion
adding 82 million/year
~ 200,000 per day!
adding 82 million/year
~ 200,000 per day!
Doubling times
250m → 500m = y ()
500m → 1b = y ()
1b → 2b = 80y (1850–1930)
2b → 4b = 75y (1930–1975)
Doubling times
250m → 500m = y ()
500m → 1b = y ()
1b → 2b = 80y (1850–1930)
2b → 4b = 75y (1930–1975)
Is the human
population reaching
carrying capacity?
33. AP Biology
Distribution of population growth
1
2
3
Time
19501900 2000
Developing countries
2050
4
5
6
7
8
9
10
11
0
Developed countries
low fertility
Worldpopulationinbillions
World total
medium
fertility
high
fertility
uneven distribution of population:
90% of births are in developing countries
uneven distribution of population:
90% of births are in developing countries
uneven distribution of resources:
wealthiest 20% consumes ~90% of resources
increasing gap between rich & poor
uneven distribution of resources:
wealthiest 20% consumes ~90% of resources
increasing gap between rich & poor
What is K
for humans?
10-15 billion?
There are choices as
to which future path
the world takes…
There are choices as
to which future path
the world takes…
the effect of income
& education
the effect of income
& education
34. AP Biology
Ecological Footprint
30.2
15.6
6.4
3.7
3.2
2.6
USA
Germany
Brazil
Indonesia
Nigeria
India
Amount of land required to support an
individual at standard of living of population
20 4 6 8 1210 14 16 18 20 22 24 26 28 30 32 34
Acres
uneven distribution:
wealthiest 20% of world:
86% consumption of resources
53% of CO2 emissions
uneven distribution:
wealthiest 20% of world:
86% consumption of resources
53% of CO2 emissions
over-population orover-population or
over-consumption?over-consumption?
over-population orover-population or
over-consumption?over-consumption?
35. AP Biology
Ecological Footprint
Based on land & water area
used to produce all resources
each country consumes & to
absorb all wastes it generates
Based on land & water area
used to produce all resources
each country consumes & to
absorb all wastes it generates
deficit surplus
37. AP Biology
Difficult to count a moving target
Measuring population density
How do we measure how many
individuals in a population?
number of individuals in an area
mark & recapture methods
sampling populations
Within a population’s geographic range, local densities may vary substantially. Variations in local density are among the most important characteristics that a population ecologist might study, since they provide insight into the environmental associations and social interactions of individuals in the population. Environmental differences—even at a local level—contribute to variation in population density; some habitat patches are simply more suitable for a species than are others. Social interactions between members of the population, which may maintain patterns of spacing between individuals, can also contribute to variation in population density.
The most common pattern of dispersion is clumped, with the individuals aggregated in patches. Plants or fungi are often clumped where soil conditions and other environmental factors favor germination and growth. For example, mushrooms may be clumped on a rotting log. Many animals spend much of their time in a particular microenvironment that satisfies their requirements. Forest insects and salamanders, for instance, are frequently clumped under logs, where the humidity tends to be higher than in more exposed areas. Clumping of animals may also be associated with mating behavior. For example, mayflies often swarm in great numbers, a behavior that increases mating chances for these insects, which survive only a day or two as reproductive adults. Group living may also increase the effectiveness of certain predators; for example, a wolf pack is more likely than a single wolf to subdue a large prey animal, such as a moose
A uniform, or evenly spaced, pattern of dispersion may result from direct interactions between individuals in the population. For example, some plants secrete chemicals that inhibit the germination and growth of nearby individuals that could compete for resources. Animals often exhibit uniform dispersion as a result of antagonistic social interactions, such as territoriality —the defense of a bounded physical space against encroachment by other individuals. Uniform patterns are not as common in populations as clumped patterns.
A Type I curve is flat at the start, reflecting low death rates during early and middle life, then drops steeply as death rates increase among older age groups. Humans and many other large mammals that produce few offspring but provide them with good care often exhibit this kind of curve. In contrast, a Type III curve drops sharply at the start, reflecting very high death rates for the young, but then flattens out as death rates decline for those few individuals that have survived to a certain critical age. This type of curve is usually associated with organisms that produce very large numbers of offspring but provide little or no care, such as long–lived plants, many fishes, and marine invertebrates. An oyster, for example, may release millions of eggs, but most offspring die as larvae from predation or other causes. Those few that survive long enough to attach to a suitable substrate and begin growing a hard shell will probably survive for a relatively long time. Type II curves are intermediate, with a constant death rate over the organism’s life span. This kind of survivorship occurs in Belding’s ground squirrels and some other rodents, various invertebrates, some lizards, and some annual plants.
A Type I curve is flat at the start, reflecting low death rates during early and middle life, then drops steeply as death rates increase among older age groups. Humans and many other large mammals that produce few offspring but provide them with good care often exhibit this kind of curve. In contrast, a Type III curve drops sharply at the start, reflecting very high death rates for the young, but then flattens out as death rates decline for those few individuals that have survived to a certain critical age. This type of curve is usually associated with organisms that produce very large numbers of offspring but provide little or no care, such as long–lived plants, many fishes, and marine invertebrates. An oyster, for example, may release millions of eggs, but most offspring die as larvae from predation or other causes. Those few that survive long enough to attach to a suitable substrate and begin growing a hard shell will probably survive for a relatively long time. Type II curves are intermediate, with a constant death rate over the organism’s life span. This kind of survivorship occurs in Belding’s ground squirrels and some other rodents, various invertebrates, some lizards, and some annual plants.
The J–shaped curve of exponential growth is characteristic of some populations that are introduced into a new or unfilled environment or whose numbers have been drastically reduced by a catastrophic event and are rebounding. The graph illustrates the exponential population growth that occurred in the population of elephants in Kruger National Park, South Africa, after they were protected from hunting. After approximately 60 years of exponential growth, the large number of elephants had caused enough damage to the park vegetation that a collapse in the elephant food supply was likely, leading to an end to population growth through starvation. To protect other species and the park ecosystem before that happened, park managers began limiting the elephant population by using birth control and exporting elephants to other countries.
Decrease rate of growth as N reaches K
The population doubled to 1 billion within the next two centuries, doubled again to 2 billion between 1850 and 1930, and doubled still again by 1975 to more than 4 billion. The global population now numbers over 6 billion people and is increasing by about 73 million each year. The population grows by approximately 201,000 people each day, the equivalent of adding a city the size of Amarillo, Texas, or Madison, Wisconsin. Every week the population increases by the size of San Antonio, Milwaukee, or Indianapolis. It takes only four years for world population growth to add the equivalent of another United States. Population ecologists predict a population of 7.3–8.4 billion people on Earth by the year 2025.
A more comprehensive approach to estimating the carrying capacity of Earth is to recognize that humans have multiple constraints: We need food, water, fuel, building materials, and other requisites, such as clothing and transportation. The ecological footprint concept summarizes the aggregate land and water area appropriated by each nation to produce all the resources it consumes and to absorb all the waste it generates. Six types of ecologically productive areas are distinguished in calculating the ecological footprint: arable land (land suitable for crops), pasture, forest, ocean, built–up land, and fossil energy land. (Fossil energy land is calculated on the basis of the land required for vegetation to absorb the CO2 produced by burning fossil fuels.) All measures are converted to land area as hectares (ha) per person (1 ha = 2.47 acres). Adding up all the ecologically productive land on the planet yields about 2 ha per person. Reserving some land for parks and conservation means reducing this allotment to 1.7 ha per person—the benchmark for comparing actual ecological footprints. The graph is the ecological footprints for 13 countries and for the whole world as of 1997. We can draw two key conclusions from the graph. First, countries vary greatly in their individual footprint size and in their available ecological capacity (the actual resource base of each country). The United States has an ecological footprint of 8.4 ha per person but has only 6.2 ha per person of available ecological capacity. In other words, the U.S. population is already above carrying capacity. By contrast, New Zealand has a larger ecological footprint of 9.8 ha per person but an available capacity of 14.3 ha per person, so it is below its carrying capacity. The second conclusion is that, in general, the world was already in ecological deficit when the study was conducted. The overall analysis suggests that the world is now at or slightly above its carrying capacity.
A more comprehensive approach to estimating the carrying capacity of Earth is to recognize that humans have multiple constraints: We need food, water, fuel, building materials, and other requisites, such as clothing and transportation. The ecological footprint concept summarizes the aggregate land and water area appropriated by each nation to produce all the resources it consumes and to absorb all the waste it generates. Six types of ecologically productive areas are distinguished in calculating the ecological footprint: arable land (land suitable for crops), pasture, forest, ocean, built–up land, and fossil energy land. (Fossil energy land is calculated on the basis of the land required for vegetation to absorb the CO2 produced by burning fossil fuels.) All measures are converted to land area as hectares (ha) per person (1 ha = 2.47 acres). Adding up all the ecologically productive land on the planet yields about 2 ha per person. Reserving some land for parks and conservation means reducing this allotment to 1.7 ha per person—the benchmark for comparing actual ecological footprints. The graph is the ecological footprints for 13 countries and for the whole world as of 1997. We can draw two key conclusions from the graph. First, countries vary greatly in their individual footprint size and in their available ecological capacity (the actual resource base of each country). The United States has an ecological footprint of 8.4 ha per person but has only 6.2 ha per person of available ecological capacity. In other words, the U.S. population is already above carrying capacity. By contrast, New Zealand has a larger ecological footprint of 9.8 ha per person but an available capacity of 14.3 ha per person, so it is below its carrying capacity. The second conclusion is that, in general, the world was already in ecological deficit when the study was conducted. The overall analysis suggests that the world is now at or slightly above its carrying capacity.