110lectcommunitiesandecosystemsstudyguidefall02

EVPP 110 Lecture

COMMUNITIES AND ECOSYSTEMS STUDY GUIDE

Fall 2002

A community is all the organisms inhabiting a particular place

what is a community?
how does a community differ from a population?
what are the four main characteristics that define a community?
explain what is meant by the "diversity" of a community and why it is important
what are the two components of community diversity?
explain what is meant by "species richness" of a community
exaplin what is meant by "relative abundance of different species" in a community
explain what is meant by the "prevalent form of vegetation" of a community and why it is important
explain what is meant by the "stability" of a community and why it is important
explain what is meant by the "trophic structure" of a community and why it is important
how could a community appear to have relatively little diversity even though it is rich in species?

Competition may occur when a shared resource is limited

what is interspecific competition?
under what circumstances does interspecific competition occur?
what concept forms the basis of the competitive exclusion principle?
what is a niche?
distinguish between the term "niche" and "habitat"
what are the two types of niches discussed in class and how are they different?
what is the relationship between a population's niche and the competitive exclusion principle?
can two species that are so similar that they compete for the same limiting resource coexist?

Predation leads to diverse adaptations in both predator and prey

what is predation?
what is a predator?
what is a prey?
can animals and plants be involved in predator-prey interactions?
why do organisms evolve mechanisms to defend against predation?
what is coevolution?
what are the two categories of defenses plants have evolved against herbivores?
what are the four types of defensive mechanisms that animals have evolved to protect against predation?
what is camouflage?
what is mimicry?
what are the two types of mimicry?
describe the difference between the two types of mimicry

Predation can maintain diversity in a community

what are some of the reasons that predators rarely drive their prey to extinction in the wild?
how can predator-prey relationships help maintain community diversity?
what is a keystone predator?
what can happen to community diversity when a keystone predator is removed?

Symbiotic relationships help structure communities

Disturbance is a prominent feature of most communities

Energy flow and chemical cycling are the two fundamental processes of ecosystems

what is an ecosystem?
what are the two fundamental processes of ecosystems?
what is energy flow?
what is chemical cycling?
why is the transfer of energy in an ecosystem referred to as energy flow instead of energy cycling?

Trophic structure determines ecosystem dynamics

what is a trophic structure?
what is the significance of the trophic structure relative to energy flow and chemical cycling in an ecosystem?
what is a food chain?
what are producers (autotrophs) and what role do they play in a ecosystems?
what type of organism is the main producer in terrestrial ecosystems?
what are consumers (heterotrophs) and what role do they play in ecosystems?
describe the relationships between producers and primary, secondary, tertiary and quaternary consumers?
what are detritivores and are they considered producers or consumers?
what is detritus?
where do producers get their energy?
where to consumers get their energy?
what is decomposition, who carries it out and what is its importance in an ecosystem?

Food chains interconnect, forming food webs

Energy supply limits the length of food chains

what is biomass?
what is primary productivity?
what is and energy pyramid?
what is the basic trend of energy flow in an ecosystem as it moves to each next higher trophic level?
energy can't be created or destroyed so what happens to the energy that doesn't make it from one trophic level to the next higher trophic level?
how does the amount of energy available to top-level consumers compare with the amount of energy available to lower-level consumers?
why are most food chains limited to 3 -5 levels?

An energy pyramid explains why meat is a luxury for humans

explain the statement "meat is a luxury for humans" in terms of an energy pyramid and the availability of energy at different trophic levels in a food chain

Chemicals are recycled between organic matter and abiotic reservoirs