WILEY ECOLOGY EXAM 3 QUESTIONS
AND ANSWERS WITH VERIFIED
SOLUTIONS 100% CORRECT (GRADED
A+)
Succession - ANSWER✔✔ change in a community (and ecosystem) over time,
often with a predictable progression of species composition
Primary succession - ANSWER✔✔ starting off from bare substrate (no soil) on
newly formed habitat (ex. After volcanic eruption, humans-responsible disturbance
like mining)
Secondary succession - ANSWER✔✔ starting off with soil, following disturbance
that doesn't remove the soil layer (ex. Forest fires, harvesting or cutting down trees
(above ground biomass), or abandoned crop field that eventually becomes natural
again)
pioneer species - ANSWER✔✔ first species to arrive after a disturbance (lichen,
moss, weed-like species are common)
Once pioneer species are established, _____ _____ start to establish.
Next, as the site gets older, ______ _______ arrive and eventually are replaced by
_____ _____ - ANSWER✔✔ woody shrubs; small trees; bigger trees
Climax community - ANSWER✔✔ the final community that tends to perpetuate
itself; considered relatively stable
,Secondary succession steps - ANSWER✔✔ event>pioneer species>intermediate
species>climax community
Primary succession steps - ANSWER✔✔ soil regions form>simple
organisms>horizons form>well-developed soil
The organisms that die in primary succession help... - ANSWER✔✔ provide
nutrients to the building soil layer
Organic matter builds up as... - ANSWER✔✔ species who live longer build up
Organic matter holds on to moisture well so moisture uptake... - ANSWER✔✔
increases as site progresses
Total biomass increases as a disturbed site becomes - ANSWER✔✔ established
(starts very low after disturbance)
light becomes limited as more ______ form - ANSWER✔✔ plants
In climax community, if you look at species above you they will be the same as
species seedlings below you but in early development... - ANSWER✔✔ it is the
opposite - species above you are not the same as species below you and that
indicates that change is going to occur
Many species can't tolerate low light conditions, so what keeps them around? -
ANSWER✔✔ forest fires
, Many pine are mid-successional species and are not part of climax community but
the fire resets or delays process of succession. Without fires, they will... -
ANSWER✔✔ be replaced by species that are a part of the climax community
Frequent fires kill off invading woody shrubs and tree seedlings which helps _____
or ______ stay established - ANSWER✔✔ grasslands; prairies
Pioneer community is at _______ of succession;
Climax community __________ of succession - ANSWER✔✔ beginning; end
point
Facilitation - ANSWER✔✔ earlier successional species modifies environment,
making it more suitable for late successional species; they increase the probability
that later successional species can become established (often by altering the
environmental conditions)
3 mechanisms of succession: - ANSWER✔✔ facilitation, inhibition, tolerance
facilitation example - ANSWER✔✔ Small plants dying provides fertilization for
soil and helps aid in establishing later successional species and giving them more
nutrient availability
inhibition - ANSWER✔✔ - presence of one species decreases the probability that a
second species will become established (negative effects on a species from
another)
- Competition, predation, parasitism
- Can prevent movement toward a climax community OR can prevent
recolonization by early successional species (promotes stability of climax
community)
AND ANSWERS WITH VERIFIED
SOLUTIONS 100% CORRECT (GRADED
A+)
Succession - ANSWER✔✔ change in a community (and ecosystem) over time,
often with a predictable progression of species composition
Primary succession - ANSWER✔✔ starting off from bare substrate (no soil) on
newly formed habitat (ex. After volcanic eruption, humans-responsible disturbance
like mining)
Secondary succession - ANSWER✔✔ starting off with soil, following disturbance
that doesn't remove the soil layer (ex. Forest fires, harvesting or cutting down trees
(above ground biomass), or abandoned crop field that eventually becomes natural
again)
pioneer species - ANSWER✔✔ first species to arrive after a disturbance (lichen,
moss, weed-like species are common)
Once pioneer species are established, _____ _____ start to establish.
Next, as the site gets older, ______ _______ arrive and eventually are replaced by
_____ _____ - ANSWER✔✔ woody shrubs; small trees; bigger trees
Climax community - ANSWER✔✔ the final community that tends to perpetuate
itself; considered relatively stable
,Secondary succession steps - ANSWER✔✔ event>pioneer species>intermediate
species>climax community
Primary succession steps - ANSWER✔✔ soil regions form>simple
organisms>horizons form>well-developed soil
The organisms that die in primary succession help... - ANSWER✔✔ provide
nutrients to the building soil layer
Organic matter builds up as... - ANSWER✔✔ species who live longer build up
Organic matter holds on to moisture well so moisture uptake... - ANSWER✔✔
increases as site progresses
Total biomass increases as a disturbed site becomes - ANSWER✔✔ established
(starts very low after disturbance)
light becomes limited as more ______ form - ANSWER✔✔ plants
In climax community, if you look at species above you they will be the same as
species seedlings below you but in early development... - ANSWER✔✔ it is the
opposite - species above you are not the same as species below you and that
indicates that change is going to occur
Many species can't tolerate low light conditions, so what keeps them around? -
ANSWER✔✔ forest fires
, Many pine are mid-successional species and are not part of climax community but
the fire resets or delays process of succession. Without fires, they will... -
ANSWER✔✔ be replaced by species that are a part of the climax community
Frequent fires kill off invading woody shrubs and tree seedlings which helps _____
or ______ stay established - ANSWER✔✔ grasslands; prairies
Pioneer community is at _______ of succession;
Climax community __________ of succession - ANSWER✔✔ beginning; end
point
Facilitation - ANSWER✔✔ earlier successional species modifies environment,
making it more suitable for late successional species; they increase the probability
that later successional species can become established (often by altering the
environmental conditions)
3 mechanisms of succession: - ANSWER✔✔ facilitation, inhibition, tolerance
facilitation example - ANSWER✔✔ Small plants dying provides fertilization for
soil and helps aid in establishing later successional species and giving them more
nutrient availability
inhibition - ANSWER✔✔ - presence of one species decreases the probability that a
second species will become established (negative effects on a species from
another)
- Competition, predation, parasitism
- Can prevent movement toward a climax community OR can prevent
recolonization by early successional species (promotes stability of climax
community)
