ENVS 200 – Final Exam Study Guide with Core
Environmental Science Concepts and Practice
Questions
1. metapopulation a population consisting of a collection of subpopulations, each one of which
has a realistic chance both of going extinct and of appearing again through
recolonization.
2. habitat patches Areas of suitable habitat for a species that are separated by areas of unsuitable
habitat.
3. disturbance Event that opens up a Gap
4. Gap patches within which many species su�er local extinction simultaneously. (In
forests, high winds, elephants, or simply the death of a tree through old age)
5. founder-con- community where species are approximately equivalent in their ability to invade
trolled gaps and can hold the gaps against all comers during their lifetime. On each
communities occasion that a population goes locally extinct a gap is opened up for invasion.
6. Priority E�ect e�ect between competing species in which the species that arrives rst at a site
is able to hold it against competing invades, whatever the outcome would be if
they competed as simultaneously arriving equals.
7. dominance-con- communities where some species are competitively superior to others and an
trolled initial colonizer of a patch cannot necessarily maintain its presence there.
communities
8. community suc- disturbances that open up gaps lead to reasonable predictable sequences of
cessions species, because di�erent species have di�erent strategies for exploiting re-
sources - early species are good colonizers and fast growers, whereas later
species can tolerate lower resource levels and grow to maturity in the presence
of early species, eventually out-competing them.
9. climax stage community reaches a point when the most e cient competitors oust there
neighbors. In this sequence, if it runs its full course, then number of species rst
increases (because of colonization) then decreases (because of competition).
,10. primary succes- sequence of species, where an opened-up gaps has not previously been in u-
sion enced by a community
11. secondary succes- subsequent sequence of species where the species of an area has been partially
sion or completely removed but seeds and spores remain.
12. Chronosequence a sequence of communities that exist over time at a given location (as a glacier
retreats, the rst stage of the succession may be observed just beyond its tip, with
later stages strung out further down the glacial valley, this series of communities
currently in existence can be used to infer what the succession must have been.
13. food web complex web of interactions between an organism, and other predators, para-
sites, food sources, and competitors within its community.
14. Tropic level each of several hierarchical levels in an ecosystem, comprising organisms that
share the same function in the food chain and the same nutritional relationship
to the primary sources of energy.
15. direct e�ects the direct impact of one individual on another when not mediated or transmitted
through a third individual (cheetah captures a gazelle or a bee pollinate a ower,
then you have observed a direct e�ect in action). Separated into categories such
as predation, competition, mutualism, etc.
16. indirect e�ects the impact of one organism or species on another that is mediated or transmitted
by a third. In other words, A (donor) has an e�ect on B (transmitter), which then
a�ects C (recipient).
17. super predator a predator at the top of a food chain, with no natural predators.
18. trophic cascade occurs when a predator reduces the abundance of its prey, and this cascades
down to the tropic level below, such as that prey's own resources increase in
abundance.
19. top-down control
, when a consumer limits a prey population. Typically the predators controlling the
abundance of the herbivores, so called top-down control.
20. bottom-up con- The abundance of predator populations at higher trophic levels is regulated by
trol the abundance of prey populations at lower trophic levels
21. meta-analysis structured analyses of large numbers of of data sets with a view to discerning
consistent trends
22. Why is the world the world is green because top-down control predominates: green plant bio-
green? mass accumulates because predators keep herbivores in check.
23. typical sequence annual weeds > herbaceous perrenials > shrubs > early successional trees > late
of dominant vege- successional trees
tation
24. species richness the number of di�erent species in a community
25. diversity indices measures that combine both species richness and the evenness or equitability
of the distribution of individuals among these species
26. purpose of diver- a community of 10 species with equal numbers in each seems more diverse
sity indicies than another with 10 species in which 91% of the individuals belong to the most
common species and just 1% to the other nine, although species diversity would
deem both equally diverse.
27. Evenness relative abundance of each species
28. niche breadth The portion of resources that a species uses (n) out of the resources available
to the community (R). The variation among individuals in a population in their
resource use.
29. niche overlap the extent of common use of a resource by two or more species denoted by o.
Environmental Science Concepts and Practice
Questions
1. metapopulation a population consisting of a collection of subpopulations, each one of which
has a realistic chance both of going extinct and of appearing again through
recolonization.
2. habitat patches Areas of suitable habitat for a species that are separated by areas of unsuitable
habitat.
3. disturbance Event that opens up a Gap
4. Gap patches within which many species su�er local extinction simultaneously. (In
forests, high winds, elephants, or simply the death of a tree through old age)
5. founder-con- community where species are approximately equivalent in their ability to invade
trolled gaps and can hold the gaps against all comers during their lifetime. On each
communities occasion that a population goes locally extinct a gap is opened up for invasion.
6. Priority E�ect e�ect between competing species in which the species that arrives rst at a site
is able to hold it against competing invades, whatever the outcome would be if
they competed as simultaneously arriving equals.
7. dominance-con- communities where some species are competitively superior to others and an
trolled initial colonizer of a patch cannot necessarily maintain its presence there.
communities
8. community suc- disturbances that open up gaps lead to reasonable predictable sequences of
cessions species, because di�erent species have di�erent strategies for exploiting re-
sources - early species are good colonizers and fast growers, whereas later
species can tolerate lower resource levels and grow to maturity in the presence
of early species, eventually out-competing them.
9. climax stage community reaches a point when the most e cient competitors oust there
neighbors. In this sequence, if it runs its full course, then number of species rst
increases (because of colonization) then decreases (because of competition).
,10. primary succes- sequence of species, where an opened-up gaps has not previously been in u-
sion enced by a community
11. secondary succes- subsequent sequence of species where the species of an area has been partially
sion or completely removed but seeds and spores remain.
12. Chronosequence a sequence of communities that exist over time at a given location (as a glacier
retreats, the rst stage of the succession may be observed just beyond its tip, with
later stages strung out further down the glacial valley, this series of communities
currently in existence can be used to infer what the succession must have been.
13. food web complex web of interactions between an organism, and other predators, para-
sites, food sources, and competitors within its community.
14. Tropic level each of several hierarchical levels in an ecosystem, comprising organisms that
share the same function in the food chain and the same nutritional relationship
to the primary sources of energy.
15. direct e�ects the direct impact of one individual on another when not mediated or transmitted
through a third individual (cheetah captures a gazelle or a bee pollinate a ower,
then you have observed a direct e�ect in action). Separated into categories such
as predation, competition, mutualism, etc.
16. indirect e�ects the impact of one organism or species on another that is mediated or transmitted
by a third. In other words, A (donor) has an e�ect on B (transmitter), which then
a�ects C (recipient).
17. super predator a predator at the top of a food chain, with no natural predators.
18. trophic cascade occurs when a predator reduces the abundance of its prey, and this cascades
down to the tropic level below, such as that prey's own resources increase in
abundance.
19. top-down control
, when a consumer limits a prey population. Typically the predators controlling the
abundance of the herbivores, so called top-down control.
20. bottom-up con- The abundance of predator populations at higher trophic levels is regulated by
trol the abundance of prey populations at lower trophic levels
21. meta-analysis structured analyses of large numbers of of data sets with a view to discerning
consistent trends
22. Why is the world the world is green because top-down control predominates: green plant bio-
green? mass accumulates because predators keep herbivores in check.
23. typical sequence annual weeds > herbaceous perrenials > shrubs > early successional trees > late
of dominant vege- successional trees
tation
24. species richness the number of di�erent species in a community
25. diversity indices measures that combine both species richness and the evenness or equitability
of the distribution of individuals among these species
26. purpose of diver- a community of 10 species with equal numbers in each seems more diverse
sity indicies than another with 10 species in which 91% of the individuals belong to the most
common species and just 1% to the other nine, although species diversity would
deem both equally diverse.
27. Evenness relative abundance of each species
28. niche breadth The portion of resources that a species uses (n) out of the resources available
to the community (R). The variation among individuals in a population in their
resource use.
29. niche overlap the extent of common use of a resource by two or more species denoted by o.
