APES Unit 2 Vocab

biodiversity

the variety of life in an ecosystem, and includes genetic diversity, species diversity, and ecosystem diversity

environmental stressor

a factor that negatively affects an organism

Generalist species

species that can survive in a variety of environmental conditions and tend to not be affected by changing habitats

genetic diversity

the variety of genes present in a single species within an ecosystem

habitat diversity

the variety and availability of habitats

population bottleneck

a significant reduction in a species population size and genetic diversity due to an environmental disruption

specialist species

species that require specific environmental conditions to survive and tend to primarily thrive in stable, unchanging habitats

species diversity

the variety of species within an ecosystem, measured by species richness and species evenness

species richness

the number of different species in an ecosystem

cultural services

non-material benefits produced by ecosystems that contribute to ideas, customs, and social behavior of human society

ecosystem services

natural processes provided by ecosystems that benefit human society and economies

provisioning services

any material good produced by ecosystems that can be used by people

regulating services

processes in ecosystems that maintain environmental conditions favorable for life

supporting services

processes in ecosystems that enable all other ecosystem services

island biogeography

the study of how factors, such as island size and distance from the mainland, affect the distribution of species on islands and their community structures

ecological tolerance

the range of abiotic conditions that an organism or species can tolerate and survive

optimum range of tolerance

the zone within the tolerance range where environmental conditions are ideal for most organisms to survive, grow, and reproduce

zone of intolerance

the zone within the tolerance range where environmental conditions are extreme with few organisms surviving and most are unable to reproduce

zone of physiological stress

the zone within the tolerance range where environmental conditions are outside the optimum range. the increased stress alters an organism’s homeostasis, which decreases its ability to survive and reproduce

earth system processes

chemical, physical, and biological processes that connect Earth’s land, atmosphere, oceans, and living organisms

episodic Earth system processes

natural events that occur at irregular but predictable intervals

periodic Earth system processes

natural events that occur regularly at predictable intervals

random Earth system processes

natural events that occur at unpredictable intervals

thermal expansion

increase in water volume due to an increase in temperature

adaptations

biological traits that improve a species’ ability to survive and reproduce in a given environment

evolution

the change in genetic traits of a population over many generations

fitness

ability of an organism to survive and reproduce

natural selection

the selection by environmental factors or selective pressures for traits the increase an organism’s ability to survive and reproduce

selective pressures

also known as environmental pressures, these are factors, such as predation or disease, that impact a species ability to survive and reproduce

climax community

a stable community structure formed in the final stage or ecological succession

ecological succession

the process in which an ecosystem’s biotic and abiotic factors gradually change over time

indicator species

organisms whose presence, abundance, or scarcity provides information on the health of an ecosystem

keystone species

organisms whose activities impact other organisms and play significant roles in community structure

pioneer species

organisms that first colonize an ecosystem and alter the conditions for the establishment of new species

primary succession

ecological succession that begins in a lifeless area without soil or sediment

secondary succession

ecological succession that occurs after a disruption causes a previously established ecosystem to be destroyed and leaves only soil