migration and dispersal are most popular terminology in bio-geographical context. Those processes help us to understand how species spread all over the earth.
Phytogeography, climate, vegetation and botanical zonesEmaSushan
This document discusses the key concepts and principles of phytogeography, which is the study of the geographic distribution of plants. It covers definitions of phytogeography, the major divisions of descriptive and interpretive phytogeography, principles related to plant environment, plant responses, migration of floras and climaxes, and perpetuation and evolution of floras. Factors affecting species distribution include geological history, migration, and ecological amplitude. The distribution of plants is primarily controlled by climate, soils, and biotic interactions, and each species has a defined range of environmental tolerances.
Palynology is the study of spores and pollen, whether living or fossil. It has been used to study plant evolution and identify plant species. There are many subfields of palynology including paleopalynology, which uses fossil spores and pollen to reconstruct past environments. Pollen and spores are prepared for analysis using various chemical treatments to remove cellular contents while preserving morphology. This allows detailed study of size, shape, and ornamentation for identification and classification.
This document discusses ecological succession, which is the process of change in species composition of a community over time. It defines primary and secondary succession, and describes different types of succession including autogenic, allogenic, autotrophic, heterotrophic, progressive, and retrogressive succession. It also discusses Clements' model of succession involving nudation, invasion, ecesis, aggregation, competition, reaction, and stabilization. Finally, it outlines three major theories of climax communities - monoclimax, polyclimax, and climax pattern theory - and three models of succession - facilitation, tolerance, and inhibition.
DPD, Water potential, Plasmolyses & ImbibitionSunita Sangwan
This document discusses diffusion pressure deficit (DPD), water potential, and related concepts in plant cells. It defines DPD as the difference between the diffusion pressure of a pure solvent and a solution. Water moves from areas of low DPD to high DPD. Water potential is the difference in free energy of water between pure water and other systems like plant cells. It depends on matric, solute, and pressure potentials. Plasmolysis occurs when cells are placed in hypertonic solutions, causing water to move out by exosmosis. Deplasmolysis is the reverse process when cells return to hypotonic solutions.
This document summarizes the nomenclature used for naming fossil plants. It discusses the history of naming conventions for plant fossils and how the current Vienna Code provides flexible taxonomic concepts for paleobotanists. Individual plant parts discovered as fossils are often named as form genera to represent detached organs like leaves, stems, or cones. When plant parts can be reconstructed into a whole organism, a binomial name may be assigned. Common plant fossil genera discussed include Lepidodendron and Calamites along with the form genera used to represent their individual parts.
Community ecology is the study of interactions between populations of different species within a defined area. A community consists of producers, consumers, and decomposers at various trophic levels. Species diversity and dominance characterize communities. Dominant species exert more influence over energy flow and physical structure. Communities develop through successional changes over time, eventually reaching a climax community. Stratification describes the vertical layering of communities according to plant height, while horizontal stratification refers to dispersion patterns of individuals across an area. Ecotones are transition zones between two communities that contain characteristics of both.
migration and dispersal are most popular terminology in bio-geographical context. Those processes help us to understand how species spread all over the earth.
Phytogeography, climate, vegetation and botanical zonesEmaSushan
This document discusses the key concepts and principles of phytogeography, which is the study of the geographic distribution of plants. It covers definitions of phytogeography, the major divisions of descriptive and interpretive phytogeography, principles related to plant environment, plant responses, migration of floras and climaxes, and perpetuation and evolution of floras. Factors affecting species distribution include geological history, migration, and ecological amplitude. The distribution of plants is primarily controlled by climate, soils, and biotic interactions, and each species has a defined range of environmental tolerances.
Palynology is the study of spores and pollen, whether living or fossil. It has been used to study plant evolution and identify plant species. There are many subfields of palynology including paleopalynology, which uses fossil spores and pollen to reconstruct past environments. Pollen and spores are prepared for analysis using various chemical treatments to remove cellular contents while preserving morphology. This allows detailed study of size, shape, and ornamentation for identification and classification.
This document discusses ecological succession, which is the process of change in species composition of a community over time. It defines primary and secondary succession, and describes different types of succession including autogenic, allogenic, autotrophic, heterotrophic, progressive, and retrogressive succession. It also discusses Clements' model of succession involving nudation, invasion, ecesis, aggregation, competition, reaction, and stabilization. Finally, it outlines three major theories of climax communities - monoclimax, polyclimax, and climax pattern theory - and three models of succession - facilitation, tolerance, and inhibition.
DPD, Water potential, Plasmolyses & ImbibitionSunita Sangwan
This document discusses diffusion pressure deficit (DPD), water potential, and related concepts in plant cells. It defines DPD as the difference between the diffusion pressure of a pure solvent and a solution. Water moves from areas of low DPD to high DPD. Water potential is the difference in free energy of water between pure water and other systems like plant cells. It depends on matric, solute, and pressure potentials. Plasmolysis occurs when cells are placed in hypertonic solutions, causing water to move out by exosmosis. Deplasmolysis is the reverse process when cells return to hypotonic solutions.
This document summarizes the nomenclature used for naming fossil plants. It discusses the history of naming conventions for plant fossils and how the current Vienna Code provides flexible taxonomic concepts for paleobotanists. Individual plant parts discovered as fossils are often named as form genera to represent detached organs like leaves, stems, or cones. When plant parts can be reconstructed into a whole organism, a binomial name may be assigned. Common plant fossil genera discussed include Lepidodendron and Calamites along with the form genera used to represent their individual parts.
Community ecology is the study of interactions between populations of different species within a defined area. A community consists of producers, consumers, and decomposers at various trophic levels. Species diversity and dominance characterize communities. Dominant species exert more influence over energy flow and physical structure. Communities develop through successional changes over time, eventually reaching a climax community. Stratification describes the vertical layering of communities according to plant height, while horizontal stratification refers to dispersion patterns of individuals across an area. Ecotones are transition zones between two communities that contain characteristics of both.
Ecological succession is the gradual replacement of one community by another until a stable climax community is established. The document describes the process of ecological succession, including primary and secondary succession. It provides examples of hydrosere succession, which begins in a body of water and progresses through stages from phytoplankton to forest. The stages include submerged plants, floating plants, reed swamp, sedge meadow, woodland, and climax forest community as the habitat becomes increasingly dry over time due to soil accumulation.
This document discusses speciation and the evolution of new species. It defines different types of speciation, including allopatric, parapatric, and sympatric speciation. Reproductive isolation is a key factor in speciation, with both prezygotic barriers that prevent interbreeding and postzygotic barriers affecting the viability of hybrid offspring. Speciation occurs over long periods of time through either gradual evolution or punctuated equilibrium. The document also covers taxonomy, phylogeny, cladistics, extinction, and adaptive radiation.
Industrial melanism refers to an increase in dark pigmentation in species caused by pollution. Peppered moths in the UK were originally pale gray but after the Industrial Revolution, habitats became darkened by soot, causing the rise of melanic black phenotypes that matched the sooty backgrounds for camouflage from predators. Experiments showed that bird predation was the driving force behind natural selection that caused populations to shift from pale to dark moths and back again as air pollution levels changed over time.
This document discusses ecological speciation, which is when divergent natural selection between different environments leads to reproductive barriers between populations. Ecological speciation can occur in allopatry, sympatry, or parapatry. Parallel speciation is a form of ecological speciation where reproductive isolation repeatedly evolves between independent populations adapting to contrasting environments. The key difference between ecological speciation and other types is that it is triggered by divergent selection between habitats, rather than processes like genetic drift or sexual selection.
Community ecology, study of the organization and functioning of communities, which are assemblages of interacting populations of the species living within a particular area or habitat.
Paleontological techniques are important for accurately studying fossils and reconstructing Earth's history. Key techniques include careful excavation using specialized tools to remove fossils from the surrounding rock matrix without damage. Fossils are also prepared, preserved, and sometimes restored in the lab. Relative and absolute dating methods are used to determine the age of fossils based on the geological layers and radioactive decay. Reconstructing fossils aids in understanding ancient life and environments.
This document discusses Zhou Yan's research interests in plant physiology, specifically stress physiology. It provides an overview of stress types in plants, including biotic, abiotic, chilling, freezing, heat, and drought stresses. It also discusses resistance mechanisms in plants, such as stress avoidance and stress tolerance. Zhou Yan's current research focuses on the effects of saline and alkaline stresses on soybean seedlings. The research examines impacts on growth factors and ionic balance, as well as the mechanisms plants use to adapt, such as osmotic regulation and ion regionalization.
Ecological niche refers to an organism's role and position in its environment, including where it finds food and shelter and what environmental conditions it requires. An organism's niche is influenced by biotic factors like availability of food and predators as well as abiotic factors like temperature, soil nutrients, and light levels. Earthworms are an example of niche construction, as they physically and chemically modify soil in a way that allows them to survive on land. Niches can be fundamental, representing all possible resources an organism could use, or realized, reflecting the niche an organism actually occupies due to competition. The competitive exclusion principle states that two species with identical niches cannot coexist long-term. Resource partitioning allows similar species to co
An ecological niche describes how a species interacts with and fits into its environment, including obtaining resources like food and shelter, and reproducing. A niche encompasses all biotic (living) and abiotic (non-living) factors. The fundamental niche is the full range of environmental conditions a species can tolerate without competition from other species. Species niches depend on factors like temperature, resources, and predators. Niches can overlap if species partition resources in non-competing ways, like dolphins and seals eating different types of fish.
This presentation describes the nutrient uptake in plants. it explains the passive and active uptake of nutrient uptake. which are further explained as diffusion, facilitated diffusion, carrier proteins, channel proteins, ion exchange & contact exchange.
Speciation is the formation of new biological species. The document provides three key points about speciation and its relationship to natural selection:
1. Speciation can occur when a single population becomes separated into two isolated groups. Over time, each group evolves differently through genetic variation and natural selection, resulting in reproductively isolated species.
2. Evidence for evolution includes the fossil record, which shows organisms changing over time and new species arising as others become extinct.
3. Natural selection plays a role in speciation when environmental changes cause isolated populations to evolve adaptations better suited to their local conditions, leading to reproductive isolation and the formation of new species over prolonged periods of separation.
This document discusses several theories on the evolutionary origins of angiosperms (flowering plants):
1. The Isoetes-Monocotyledon theory proposes that monocotyledons evolved from various groups of pteridophytes through a hypothetical intermediate called Proangiosperms. However, modern views consider the similarities between Isoetes and monocots to be superficial.
2. The Conifer-Amentiferae theory suggests that angiosperms evolved from conifers like Cordaites. While amentiferous plants like willows share some features with conifers, they are now seen as specialized, not primitive.
3. The Gnetales-Ang
Speciation is the process by which new biological species develop. It occurs through reproductive isolation, which can develop due to geographic barriers separating populations or behavioral/ecological factors preventing interbreeding. There are several types of speciation including allopatric, where populations are isolated geographically; parapatric, involving isolation in adjacent habitats; and sympatric, occurring without geographic separation through mechanisms like habitat differentiation. Reproductive barriers that maintain species include prezygotic barriers preventing fertilization and postzygotic barriers hindering viable offspring.
This presentation intends to give a bird's eye view of different abiotic ecological factors with special reference to light, temperature, fire and wind and their impact on ecosystem.
1. Cladistics is a method of classifying organisms based on shared derived characteristics and evolutionary relationships rather than physical similarity. It uses characteristics inherited from common ancestors to construct branching cladograms depicting evolutionary descent.
2. Determining whether a characteristic is ancestral or derived is important in cladistics. Ancestral characteristics predate the last common ancestor, while derived traits evolved more recently. Outgroup comparison is used to determine polarity.
3. A cladogram depicts nested clades of organisms sharing synapomorphies not found in outgroups. It shows the pattern of common ancestry and branching of life over time based on inheritance of characteristics from ancestors.
The document discusses disjunct distribution of plants, which refers to a pattern where the ranges of a species are separated into disconnected areas. It defines different types of disjunct distributions, including bipolar, altitudinal, and amphitropical. Factors that can lead to disjunction are discussed, such as evolution, long distance dispersal, climatic changes, and continental drift. Specific examples of disjunct distributions are given, such as Arctic-Alpine, North Atlantic, Mediterranean, and South Pacific types. Diagrams and maps are provided to illustrate different disjunct distribution patterns.
The document defines niche as the range of conditions a species lives in and how it obtains resources to survive and reproduce. A niche explains how a species fits into an ecosystem. Habitat is a species' location while niche includes location and occupation. The document also defines competition as occurring when organisms seek the same limited resources in the same place and time, and can be intraspecific or interspecific. The competitive exclusion principle states that no two species can occupy the exact same niche, while niche partitioning allows species to divide resources and coexist by each occupying a different niche.
Plant Community- definition, concept and structureEmaSushan
This document defines community as populations of species living and interacting in an area over time. It discusses the concept of a community, which comprises multiple interacting populations sharing a common habitat. The composition of a biotic community is determined by environmental conditions and the ecological tolerance of species populations. Communities exhibit characteristics like diversity, density, and stratification. They can be categorized based on habitat features like water availability or light exposure. Communities are dynamic systems that change over time through succession as they interact with a also changing environment.
The document discusses invasive species and their impacts. It defines native, non-native, and invasive species. Many species have been introduced intentionally or accidentally through human activities like transportation. Invasive species can negatively impact ecosystems by outcompeting native species for resources, preying on native species, introducing diseases, altering habitats, and through hybridization. Their introduction has driven many plant and animal species extinct. Characteristics like rapid reproduction and lack of natural predators allow some introduced species to become invasive.
This document discusses the principles and importance of plant geography and the phytogeographic regions of India. It provides definitions of key terms like phytogeography, flora, and biogeography. It then outlines 13 principles of phytogeography related to the environment, plant responses, migration of floras, and perpetuation/evolution of floras. The document divides India into 9 main phytogeographic regions based on climate and vegetation types. It provides details on the characteristic vegetation found in each region. Understanding plant distributions and the factors influencing them is important for fields like ecology, evolution, and conservation biogeography.
This document provides an introduction to biodiversity and discusses it at multiple levels - genetic, species, ecosystem, and landscape. It defines biodiversity as the variety of living organisms, including diversity within and between species. Genetic diversity refers to variation within species and between populations, and is important for plant and animal breeding. Species diversity is the number of species within an area or ecosystem. Ecosystem diversity looks at the variety of habitats and biological communities within a region. The document examines these concepts and provides examples like genetic diversity in maize and major ecosystem types around the world.
Ecological succession is the gradual replacement of one community by another until a stable climax community is established. The document describes the process of ecological succession, including primary and secondary succession. It provides examples of hydrosere succession, which begins in a body of water and progresses through stages from phytoplankton to forest. The stages include submerged plants, floating plants, reed swamp, sedge meadow, woodland, and climax forest community as the habitat becomes increasingly dry over time due to soil accumulation.
This document discusses speciation and the evolution of new species. It defines different types of speciation, including allopatric, parapatric, and sympatric speciation. Reproductive isolation is a key factor in speciation, with both prezygotic barriers that prevent interbreeding and postzygotic barriers affecting the viability of hybrid offspring. Speciation occurs over long periods of time through either gradual evolution or punctuated equilibrium. The document also covers taxonomy, phylogeny, cladistics, extinction, and adaptive radiation.
Industrial melanism refers to an increase in dark pigmentation in species caused by pollution. Peppered moths in the UK were originally pale gray but after the Industrial Revolution, habitats became darkened by soot, causing the rise of melanic black phenotypes that matched the sooty backgrounds for camouflage from predators. Experiments showed that bird predation was the driving force behind natural selection that caused populations to shift from pale to dark moths and back again as air pollution levels changed over time.
This document discusses ecological speciation, which is when divergent natural selection between different environments leads to reproductive barriers between populations. Ecological speciation can occur in allopatry, sympatry, or parapatry. Parallel speciation is a form of ecological speciation where reproductive isolation repeatedly evolves between independent populations adapting to contrasting environments. The key difference between ecological speciation and other types is that it is triggered by divergent selection between habitats, rather than processes like genetic drift or sexual selection.
Community ecology, study of the organization and functioning of communities, which are assemblages of interacting populations of the species living within a particular area or habitat.
Paleontological techniques are important for accurately studying fossils and reconstructing Earth's history. Key techniques include careful excavation using specialized tools to remove fossils from the surrounding rock matrix without damage. Fossils are also prepared, preserved, and sometimes restored in the lab. Relative and absolute dating methods are used to determine the age of fossils based on the geological layers and radioactive decay. Reconstructing fossils aids in understanding ancient life and environments.
This document discusses Zhou Yan's research interests in plant physiology, specifically stress physiology. It provides an overview of stress types in plants, including biotic, abiotic, chilling, freezing, heat, and drought stresses. It also discusses resistance mechanisms in plants, such as stress avoidance and stress tolerance. Zhou Yan's current research focuses on the effects of saline and alkaline stresses on soybean seedlings. The research examines impacts on growth factors and ionic balance, as well as the mechanisms plants use to adapt, such as osmotic regulation and ion regionalization.
Ecological niche refers to an organism's role and position in its environment, including where it finds food and shelter and what environmental conditions it requires. An organism's niche is influenced by biotic factors like availability of food and predators as well as abiotic factors like temperature, soil nutrients, and light levels. Earthworms are an example of niche construction, as they physically and chemically modify soil in a way that allows them to survive on land. Niches can be fundamental, representing all possible resources an organism could use, or realized, reflecting the niche an organism actually occupies due to competition. The competitive exclusion principle states that two species with identical niches cannot coexist long-term. Resource partitioning allows similar species to co
An ecological niche describes how a species interacts with and fits into its environment, including obtaining resources like food and shelter, and reproducing. A niche encompasses all biotic (living) and abiotic (non-living) factors. The fundamental niche is the full range of environmental conditions a species can tolerate without competition from other species. Species niches depend on factors like temperature, resources, and predators. Niches can overlap if species partition resources in non-competing ways, like dolphins and seals eating different types of fish.
This presentation describes the nutrient uptake in plants. it explains the passive and active uptake of nutrient uptake. which are further explained as diffusion, facilitated diffusion, carrier proteins, channel proteins, ion exchange & contact exchange.
Speciation is the formation of new biological species. The document provides three key points about speciation and its relationship to natural selection:
1. Speciation can occur when a single population becomes separated into two isolated groups. Over time, each group evolves differently through genetic variation and natural selection, resulting in reproductively isolated species.
2. Evidence for evolution includes the fossil record, which shows organisms changing over time and new species arising as others become extinct.
3. Natural selection plays a role in speciation when environmental changes cause isolated populations to evolve adaptations better suited to their local conditions, leading to reproductive isolation and the formation of new species over prolonged periods of separation.
This document discusses several theories on the evolutionary origins of angiosperms (flowering plants):
1. The Isoetes-Monocotyledon theory proposes that monocotyledons evolved from various groups of pteridophytes through a hypothetical intermediate called Proangiosperms. However, modern views consider the similarities between Isoetes and monocots to be superficial.
2. The Conifer-Amentiferae theory suggests that angiosperms evolved from conifers like Cordaites. While amentiferous plants like willows share some features with conifers, they are now seen as specialized, not primitive.
3. The Gnetales-Ang
Speciation is the process by which new biological species develop. It occurs through reproductive isolation, which can develop due to geographic barriers separating populations or behavioral/ecological factors preventing interbreeding. There are several types of speciation including allopatric, where populations are isolated geographically; parapatric, involving isolation in adjacent habitats; and sympatric, occurring without geographic separation through mechanisms like habitat differentiation. Reproductive barriers that maintain species include prezygotic barriers preventing fertilization and postzygotic barriers hindering viable offspring.
This presentation intends to give a bird's eye view of different abiotic ecological factors with special reference to light, temperature, fire and wind and their impact on ecosystem.
1. Cladistics is a method of classifying organisms based on shared derived characteristics and evolutionary relationships rather than physical similarity. It uses characteristics inherited from common ancestors to construct branching cladograms depicting evolutionary descent.
2. Determining whether a characteristic is ancestral or derived is important in cladistics. Ancestral characteristics predate the last common ancestor, while derived traits evolved more recently. Outgroup comparison is used to determine polarity.
3. A cladogram depicts nested clades of organisms sharing synapomorphies not found in outgroups. It shows the pattern of common ancestry and branching of life over time based on inheritance of characteristics from ancestors.
The document discusses disjunct distribution of plants, which refers to a pattern where the ranges of a species are separated into disconnected areas. It defines different types of disjunct distributions, including bipolar, altitudinal, and amphitropical. Factors that can lead to disjunction are discussed, such as evolution, long distance dispersal, climatic changes, and continental drift. Specific examples of disjunct distributions are given, such as Arctic-Alpine, North Atlantic, Mediterranean, and South Pacific types. Diagrams and maps are provided to illustrate different disjunct distribution patterns.
The document defines niche as the range of conditions a species lives in and how it obtains resources to survive and reproduce. A niche explains how a species fits into an ecosystem. Habitat is a species' location while niche includes location and occupation. The document also defines competition as occurring when organisms seek the same limited resources in the same place and time, and can be intraspecific or interspecific. The competitive exclusion principle states that no two species can occupy the exact same niche, while niche partitioning allows species to divide resources and coexist by each occupying a different niche.
Plant Community- definition, concept and structureEmaSushan
This document defines community as populations of species living and interacting in an area over time. It discusses the concept of a community, which comprises multiple interacting populations sharing a common habitat. The composition of a biotic community is determined by environmental conditions and the ecological tolerance of species populations. Communities exhibit characteristics like diversity, density, and stratification. They can be categorized based on habitat features like water availability or light exposure. Communities are dynamic systems that change over time through succession as they interact with a also changing environment.
The document discusses invasive species and their impacts. It defines native, non-native, and invasive species. Many species have been introduced intentionally or accidentally through human activities like transportation. Invasive species can negatively impact ecosystems by outcompeting native species for resources, preying on native species, introducing diseases, altering habitats, and through hybridization. Their introduction has driven many plant and animal species extinct. Characteristics like rapid reproduction and lack of natural predators allow some introduced species to become invasive.
This document discusses the principles and importance of plant geography and the phytogeographic regions of India. It provides definitions of key terms like phytogeography, flora, and biogeography. It then outlines 13 principles of phytogeography related to the environment, plant responses, migration of floras, and perpetuation/evolution of floras. The document divides India into 9 main phytogeographic regions based on climate and vegetation types. It provides details on the characteristic vegetation found in each region. Understanding plant distributions and the factors influencing them is important for fields like ecology, evolution, and conservation biogeography.
This document provides an introduction to biodiversity and discusses it at multiple levels - genetic, species, ecosystem, and landscape. It defines biodiversity as the variety of living organisms, including diversity within and between species. Genetic diversity refers to variation within species and between populations, and is important for plant and animal breeding. Species diversity is the number of species within an area or ecosystem. Ecosystem diversity looks at the variety of habitats and biological communities within a region. The document examines these concepts and provides examples like genetic diversity in maize and major ecosystem types around the world.
The document discusses biodiversity and its conservation. It defines biodiversity as the diversity among biological organisms, including genes, species, and ecosystems in a region. It then describes the three main types of biodiversity: genetic diversity, species diversity, and ecological diversity. The document outlines some of the major threats to biodiversity, such as habitat loss, climate change, overexploitation, pollution, and invasive species. It also discusses patterns of biodiversity like latitudinal gradients and species-area relationships. Finally, it covers the importance of conserving biodiversity and different conservation methods like in-situ and ex-situ conservation.
This document provides an overview of community ecology, including definitions, characteristics, structures, and classifications of biological communities. The key points are:
1) A biological community is an assemblage of interacting plant and animal species that coexist in a particular area. Characteristics include species diversity, growth forms, dominance by certain species, successional changes over time, and trophic levels.
2) Communities vary in size from small microbe groups to large forests spanning thousands of square kilometers. Structurally, communities can be open or closed.
3) Communities are classified and analyzed using various quantitative and qualitative characters such as frequency, density, abundance, cover, stratification, and life forms. Classification systems include
Ch 15 - Biodiversity and Conservation || Class 12 ||SAQIB AHMED
Biodiversity refers to the variety of plant and animal life on Earth. It includes genetic diversity within species, diversity of species, and diversity of ecosystems. Maintaining biodiversity is important because all species are interconnected and play vital roles in ecosystems. The major threats to biodiversity are habitat loss, overexploitation, invasive species, and coextinctions. At current extinction rates, half of all species may be lost within 100 years, constituting a human-caused sixth mass extinction.
This document discusses biodiversity, defining it as the variety of life on Earth, including diversity of ecosystems, species, and genes. It notes that biodiversity is highest in tropical regions and concentrated in biodiversity hotspots. While biodiversity provides numerous benefits, it faces threats such as habitat loss, pollution, and climate change. Some scientists estimate that thousands of species are going extinct each year, threatening both biodiversity and human survival in the long run. Conservation of biodiversity across entire ecosystems is needed to protect life on Earth.
best ever ppt on ecological succession by nageshNagesh sadili
This document discusses ecological succession. It begins by defining succession as the process of change in species structure over time within a community. Succession can be initiated by disturbances like lava flows or landslides. There are two main types - primary succession, which occurs on new sites without soil like volcanic areas, and secondary succession, which occurs on sites that were previously inhabited but have been disturbed, like areas after forest fires. The document outlines the key stages and processes in both primary and secondary succession, from colonization by pioneer species to the development of a climax community. Examples of primary succession include the formation of soils and ecosystems on Surtsey island after volcanic eruptions.
Community ecology is the study of the interactions between species within a biological community. A community is defined as an assemblage of plant and animal species that occur together in a specific habitat. Characteristics of a community include species diversity, dominance by one or a few species, trophic structure consisting of producers, consumers, and decomposers, and successional changes over time. Communities can be classified and analyzed based on quantitative characteristics like frequency, density, and cover, and qualitative characteristics like physiognomy, phenology, and stratification. Ecotones form transitional zones between two adjacent communities, and the biological spectrum indicates the distribution of life forms in a community.
This document defines biodiversity and discusses its importance. It begins by defining biodiversity as the variety of life on Earth, including diversity within and between species. It then discusses how biodiversity is being lost due to human activities, referring to the current extinction crisis as the 6th mass extinction. The document outlines the different levels of biodiversity, including genetic, species, and ecosystem diversity. It emphasizes the importance of conserving biodiversity through both legal protections and non-legal efforts.
This document discusses different types of endemism and theories of endemism. It defines endemism as species that live only in a particular location. There are two main types discussed - relic endemics which are ancient species restricted to few areas due to past climate changes, and neo-endemics which are recently formed species, often through hybridization. The age and area hypothesis proposes that older species have larger distributions while younger neo-endemic species have smaller ranges. Factors like isolation, mutations, and natural crosses can lead to the formation of new endemic species. Some examples of endemic plants in India are provided.
This document provides an overview of alien species and evolutionary ecology. It defines key terms and outlines the history of the field. It discusses the large number and impacts of alien species introductions in North America, particularly their ecological and economic costs. It explores how the introduction of alien species can lead to rapid evolution in both alien and native species through processes like dispersal adaptation, establishment in new environments, and interactions with climate change. The document also notes conservation challenges around defining alien species in a changing climate.
This document provides an overview of alien species and evolutionary ecology. It defines key terms and outlines the history of the field. It discusses the large number and widespread distribution of alien species in North America, and their significant ecological and economic impacts. It explores how the introduction of alien species can lead to rapid evolution in both alien and native species through processes like dispersal adaptation, and adaptation to new environments. It also discusses factors like time lags, climate change, and their implications for conservation concerns regarding what is considered native or alien.
The document provides an overview of ecosystems, including definitions, components, and classifications. It defines an ecosystem as a system where biotic and abiotic factors interact. It describes trophic structures and food chains, with producers, primary consumers, secondary consumers, and decomposers. It also discusses gradients, ecotones, and the importance of diversity at the genetic, species, and ecosystem levels. Ecosystems are classified as either natural or artificial, with natural ecosystems further divided into aquatic (marine and freshwater) and terrestrial systems. Examples of different ecosystem types are provided.
This document defines key terms related to ecology, wildlife management, habitats, and species biology. It discusses the relationships between soils, plant growth, and wildlife. Soil fertility influences the productivity of plants and wildlife populations. While wildlife can adapt to less fertile soils, the most productive habitats for wildlife are generally those with more fertile soils that support a diversity of food and cover resources. Land use practices can negatively impact soil fertility and wildlife habitat if not implemented carefully.
This is the 6th lesson of the course - Foundation of Environmental Management taught at the Faculty of Social Sciences and Humanities, Rajarata University of Sri Lanka
1. Many factors influence the geographic distribution of species, including barriers, dispersal abilities, climate, competition and vicariance events.
2. Vicariance, such as continental drift, can split a once continuous population into isolated groups, leading to independent evolution and discontinuous distributions.
3. Climate is a major limiting factor for species distributions, and climate change is projected to profoundly impact the Earth's biota by altering temperature and moisture conditions within species' ranges.
This document discusses ecological succession, including primary and secondary succession. It provides examples of primary succession on new landscapes like volcanic islands or glacial retreat. Secondary succession is examined using a case study of an old field recovering from agriculture. The document also discusses how disturbances can impact succession, creating ecotones and edge effects. The intermediate disturbance hypothesis is presented, suggesting peak diversity at moderate disturbance levels. Island biogeography theories are summarized, relating them to habitat fragmentation. The solution of wildlife corridors is proposed to address fragmentation effects.
Similar to Phytogeography........................pptx (20)
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
2. CONTENT
• Introduction
• Principles governing plant distribution
• Different types of distribution
• Theories of distribution
• Factors affecting plant distribution
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3. INTRODUCTION
• It is the branch of biogeography that is concerned with the geographic distribution of
plant species and their influence on the earths surface .
• The term is derived from two words ‘phyto’ meaning plant and ‘geography’ meaning
distribution
• It covers all the aspects of plant distribution including the individual species and the
factors that regulate the composition of communities and flora.
• Phytogeography encompasses various fields such as environment, flora(taxa),
vegetation(plant community) and origin.
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4. ASPECTS
• Phytogeography has two basic aspects
1. Ecological phytogeography:- It deals with the role of biotic and abiotic
interactions on plant distribution
2. Historical phytogeography :- It is related to historical reconstruction of the origin,
dispersal and extinction of taxa .
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5. PHYTOGEOGRAPHY
• According to Campbell 1926 the main theme of plant geography is to discover the
similarities and diversities in the plants and floras of the present and past found in widely
separated parts of the earth
• Wulff 1943 states that phytogeography is the study of distribution of plant species in
their habitats and elucidation of origin and history of development of floras .
• According to Croizat 1952 phytogeography is the study of migration and evolution of
plants in time and space .
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6. FATHER OF PHYTOGEOGRAHY
• One of the subjects earliest proponents was Prussian
naturalist Alexander von Humboldt who is often referred to
as the father of phytogeography .
• Humboldt advocated a quantitative approach to
phytogeography that has characterized modern plant
geography
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7. Major Divisions of Phytogeography
• There are two major divisions of Phytogeography:
• (i) Descriptive or Static Phytogeography
• (ii) Interpretive or Dynamic Phytogeography
• Descriptive Phytogeography: This deals with the actual description of floristic or
vegetational groups found in different parts of the world.
• Early plant geographers described floras and attempted to divide earth into floristic and
botanical zones.
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8. Major Divisions of Phytogeography
• Interpretive or Dynamic Phytogeography :This deals with the dynamics of migration and
evolution of plants and floras.
• It explains the reasons for varied distribution of plant species in different parts of the world.
• It is a borderline science involving synthesis and integration of data and concepts from
several specialized disciplines like ecology, physiology, genetics, taxonomy, evolution,
paleontology and geology.
• Good (1931I), Mason (1936), Cain (1944) and some others have pointed out the factors
involved in the distribution of plants
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9. • Lowerence (1951) has suggested the modern principles of Phytogeography which
are classified into four groups:
• I. Principles concerning environment
• II. Principles concerning plant responses
• III. Principles concerning the migration of floras and climaxes
• IV. Principles concerning the perpetuation and evolution of floras and climaxes
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10. PRINCIPLES CONCERNING ENVIRONMENT
• The distribution of plants is primarily controlled by climatic conditions.
• There has been variation in climate during geological history in the past which affected
migration of plants.
• The relations between land masses and seas have varied in the past. The large land
masses split up to form new land masses or continents which separated and reoriented.
Land bridges between continents acted as probable routes for migration of plant and
animal species.
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11. • The land bridges became submerged in sea with the passage of time and the
possibility for migration of plants and animals from one continent to another
disappeared for ever.
• Soil conditions on plains and mountains of different land masses show secondary
control on distribution of vegetation. Halophytes, psammophytes, calcicols etc. have
developed because of edaphic conditions.
• Biotic factors also play important role in distribution and establishment of plant
species.
• The environment is holocentric, i.e., all environmental factors have combined effects
on the vegetation of a place.
PRINCIPLES CONCERNING ENVIRONMENT
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12. PRINCIPLES CONCERNING
PLANT RESPONSES
• Range of distribution of plants is limited by their tolerances. Each plant species has a range
of climatic and edaphic conditions. Therefore, tolerance of a large taxon is the sum of
tolerances of its constituent species.
• Tolerances have a Genetic basis. The response of plants to environment is governed by
their genetic makeup.
• Many of the crops through breeding and genetic changes have been made to grow in
wider range of environmental conditions. In nature, hybrid plants have been found to have
wider range of tolerances than their parents.
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13. PRINCIPLES CONCERNING
PLANT RESPONSES
• Different ontogenetic phases have different tolerances.
• Different developmental stages of plants show different degree of tolerances, as for
example seeds and mature plants are more tolerant to temperature and moisture
variations than their seedlings.
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14. PRINCIPLES CONCERNINGTHE
MIGRATION OF FLORAS AND CLIMAXES
• Large scale migrations have taken place. The fossils and palaeoecological evidences reveal
that large scale migrations of plants and animals have taken place during Mesozoic era
andTertiary periods.
• Migration resulted from transport and establishment. In the process of migration plants
are dispersed to new habitats through their propagules such as spores, seeds, bulbils etc.,
and there they are established if environmental conditions are favourable. Plants grow
and reproduce there and progeny perpetuates through ecological adjustments
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15. PRINCIPLESCONCERNINGTHE
PERPUTATION AND EVOLUTION OF
FLORAS AND CLIMAXES
• Perpetuation depends first upon migration and secondly upon the ability of species to
transmit the favorable variations to the progenies.
• Evolution of floras and climaxes depends upon migration, evolution of species and
environmental selections.
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16. Distribution
• On the basis of area of the earth surface occupied by the plants, the various taxa are
categorized as under:
1.Continous distribution
2. Wides
3.Endemics
4. Discontinuous species
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17. CONTINOUS DISTRIBUTION
• Some taxa are uniformly distributed in the area and give rise to continuous distribution .
• Four main types :
• 1. the cosmopolitan
• 2. the circumpolar
• 3. the circumboreal
• 4. the pantropic
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18. • Cosmopolitan
• These taxa are distributed all over the globe.They occur in all six widely inhabited continents.
• eg:- many weeds and lower groups of cryptograms
• Circumpolar
• Taxa distributed around the north or south pole
• eg:- Saxifraga oppositifolia
• Circumboreal
• Taxa distributed around the boreal zone .
• eg:- Ribes (gooseberries)
• Pantropic
• Taxa occurring practically throughout the tropics or at least widespread in the tropical region in
Asia ,Africa and America.
• eg :- Palm family
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19. WIDES
• Plants widely distributed over the earth in definite climatic zones and the different
continents are referred to as wides.
• Cosmopolitan is applied for wides but in fact, no plant is cosmopolitan in real sense of
the term.
• Taraxacum officinale and Chaenopodium album are the common examples of the
wides. Plants of tropical regions are called Pantropical.
• The plants of very cold climate may not only be found in the arctic regions but also in
alpine zone of mountains in tropical and subtropical regions. These are called arctic-
alpine plants.
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20. ENDEMICS
• A taxon whose distribution is confined to a given area is said to be endemic to that
area
• The taxon may be of any rank, although it is usually at a family level or below, and its
range of distribution may be wide, spanning an entire continent, or very narrow
covering only a few square meters.
• The concept of endemism is important because in the past the formulation of
biogeographic regions was based on it.
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21. • Now the endemic species have been grouped into the following categories:
• (i) Relics or Paleoendemics: They are the survivors of once widely distributed ancestral
forms, for example, Ginkgo biloba (restricted to China and Japan), Sequoia sempervirens
(confined to coastal valleys of California, U.S.A.).
• These species are called Paleoendemics or epibionts. A great majority of the endemic
species belonging to this type have many fossil relatives.
• They are also called living fossils. Because of little variability the endemics are adapted
only to a particular environment and even if they reach new areas, they fail to establish
themselves in new environment.
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22. • (ii) Neo endemics:
• The other endemics may be modern species which have had not enough time for
occupying a large area through migration.They are called neo endemics.
• There are several such genera which are widely endemic or few species of which are
endemic.
• Neo endemics show good variability and have many biotypes, grow in diverse
habitats and have wide tolerance for habitats.
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23. • (iii) Pseudo endemics:
• These endemics arise due to mutation in existing population at a particular place.
• These pseudo endemics or mutants may or may not persist for long in the particular
area where they originate.
• Endemism results from the failure on the part of species to disseminate its seeds fruits
spores or propagules because of existence of great barriers like mountains, oceans and
large deserts.
• The oceanic islands which are isolated from rest of the world by large expanses of
water abound in endemic species and water barrier checks the migration of those
species outside their original habitat.
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24. DISCONTINOUS DISTRIBUTION
• When plants occur at two or more distant places of the world which are separated by
overland’s or oceans hundreds or thousands of kilometers apart. Such a distribution is
called discontinuous or disjunct distribution.
• Familiar discontinuous ranges are:-
1. Artic-Alpine 6. Mediterranean 11. Gondwana type
2.North Atlantic 7. Tropical
3.North Pacific 8. South- Pacific
4.North-South American 9. South – Atlantic
5.Europe-Asian 10. Antarctic
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25. • Artic-Alpine :
• Taxa distributed in arctic region and in mountainous system of temperate zone.
• North Atlantic:
• Taxa distributed in North America and Europe and also some times locally in Asia .
• North Pacific:
• Taxa distributed chiefly in North America and Eastern Asia
• North-South American :
• Taxa distributed in North- South America but lacking continuity in between
• Europe-Asian :
• Taxa distributed in Europe and Asia but lacking continuity in between
• Mediterranean :
• Taxa distributed at European and African shore of Mediterranean sea
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26. • Tropical:
• Taxa distributed in two or more separate tropical regions.
• South Pacific :
• Taxa distributed at least in South America and New Zealand
• South Atlantic :
• Taxa distributed at least in South America andAfrica
• Antarctic :
• Taxa distributed on Antarctic mainland and parts of South America , New Zealand and Australia
islands
• Gondwana type:
• Taxa distributed in more than one continent which tends to embrace Africa, Madagascar , India,
Australia
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27. • The significant phytogeographical causes for discontinuous distribution are as
follows:
• (i) The species might have evolved at more than one place and they failed to migrate
outside their original habitats because of barriers.
• (ii) The species which were once widely distributed in the past disappeared from certain
areas and are now surviving in some distant pockets.
• (iii) The climate may also be a factor for discontinuity in distribution of species. Plants
having specific climatic requirements are found in widely separated areas with similar
environmental conditions.
• For example, plants of arctic regions are also found in alpine zone of high mountains in
tropics and subtropics.
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28. Theories of Discontinuous Distribution:
• Theory of Land Bridge:
• According to this theory, land bridges occurring in between the separated continents
are believed to have helped in the migration of various taxa from one continent to the
other.
• Uniform distribution of plants and animals in different parts of the world during
Paleozoic era is believed to have been due to those land bridges.
• With the passage of time the land bridges became submerged in sea and the
connections between the various continents snapped beyond the dispersal capacity of
organisms resulting thereby the discontinuity in the distribution
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29. • Theory of Continental drift:
• The theory of continental drift was propounded by Wegner (1912 1924) According to
him the whole land- mass of the world was a single super continent during Paleozoic
era. He named it as Pangaea.
• That super continent was surrounded by sea on all the sides which was named
Panthalassa. During Mesozoic, Pangaea split up into two large landmasses; Laurasia in
the north and Gondwanaland in south.
• About 135 million years ago reorientation of continents began. The continents were
drifted apart by the oceans.This is called Continental Drift.
• The occurrence of Dinosaurs and many fossil plants lend support to the existence of
Laurasia and Gondwanaland.
• With the separation of continents the distribution areas of several plant and animal
species got separated and gave rise to discontinuous distribution areas.
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30. Factors Affecting Distribution of Species
• Several factors are known to affect the geographical distribution of plant species, some of
which are as follows:
• 1. Geological history and distribution
• 2. Migration
• 3. Ecological amplitude.
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31. Geological history and distribution
• The place where a species first originated is called its centre of origin. Evolution of species is a
slow but continuous process. Some of the species in present day flora are quite old while a great
majority of them are recent in origin.
• The process of species differentiation involves:
• (i) Hybridization between the related species as well as mutation
• (ii)The natural selection of the hybrid and mutant populations.
• In the selection process not all the hybrids and mutants are selected by nature and only the
fittest individuals which find the habitat conditions within their ecological amplitudes are
selected and the individuals least fit are eliminated. Changing climate has also played important
role in the origin of new species. In the course of evolution several old species became extinct,
some of which can be found even today as fossils. The fossils provide direct evidence for the
existence of various taxa in the past.
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32. MIGRATION
• The newly evolved species starts migration to new areas and side by side it undergoes further
evolutionary changes. The dispersal of propagules is brought about by several agencies like wind,
water, glaciers, insects, animals, even man.
• Migration may be adversely affected and sometimes even totally stopped by some factors called
migration barriers. Barriers in the dispersal of species may be classified as ecological or
environmental and geographical.
• The climate, an ecological barrier, plays important role in distribution and establishment of
species. Unsuitable climatic condition or change of climate in particular area forces the species to
migrate from one place to another and the failure of some species to migration leads them to
gradual extinction.
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33. • Besides climate, there are geographical barriers, as for example, high mountains, vast oceans or
deserts.
• The fresh water plants, for example, cannot be dispersed across oceans if their propagules are
suitable only for fresh water dispersal and similarly propagules of land plants from one country
cannot reach other country separated by vast oceans and mountains.
• Species are called natives of the place of occurrence if they originated there. Outside the area
of its origin, the species is referred to as exotic. Exotic species reach new area through
migration. If any species is introduced intentionally in new area by man then it is called
introduced species.
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34. Ecological amplitudes and distribution
• Environmental conditions not only influence the life and development of plants but also
determine the presence or absence, vigor or weakness and relative success or failure of various
plants in a particular habitat.
• Each plant species of a community has a definite range of tolerance towards physical and
biological environment of the habitat.This is referred to as ecological amplitude.
• The ecological amplitude is governed by genetic set up of the species concerned and thus
different species have different ecological amplitudes which may sometimes overlap only in
certain respects.
• Further, some species may occur at different geographical regions as and when the conditions
fall within their ecological amplitudes. As for example, some plants of temperate region say
conifers, may also be found in alpine zone of high mountains in tropical and subtropical regions.
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35. • The other consideration in ecological amplitude as a factor in plant distribution is its change
with time. In sexually reproducing plants the hybridization between related species results in
offspring’s with new genetic composition.
• With the change of environment the plant species also make adjustments with new
environment by shifts in their ecological amplitudes facilitated by changes in the genotype.
• Within a species there may occur several genetically different groups of individuals
(populations) which are adjusted to particular set of ecological conditions.
• These populations are called ecotypes or ecological races or ecological populations.
• In Euphorbia thymifolia, for example, there are two major populations-one is calcium loving or
calcicole and the other type is calcium hating or calcifuge.
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36. REFERENCES
• Amit Pandey , Pandey K., Shukla J. P., “Environmental Biology and Ecology” Narendra Publishing
House- 2009. Page no. 178- 205.
• Arumugam. N., Kumaresan.V., “Plant Ecology and Phytogeography” Saras Publication, 2010
• http://www.biologydiscussion.com/ecology/phytogeography-climate-vegetation-and-botanical-
zones-of-india/6925
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