Lecture 29: Community Ecology Flashcards
(24 cards)
- An assemblage of populations of various species living close enough for potential interactions is a:
A) Community
B) Supra-Population
C) Sub-Population
D) Niche
A) Community
- Approximately how many KG of carnivore biomass can be supported by a field plot containing 1000 KG of plant material?
A) 1000
B) 100
C) 10
D) 1
B) 100
- What interactions exist between mycorrhizae and evergreen tree roots?
A. +/0
B. -/-
C. -/+
D. +/+
D. +/+
- Which of the following terms is used by ecologists to describe the community interactions where one organism makes the environment more suitable for another organism? Without direct contact
A) Mutualism
B) Parasitism
C) Facilitation
D) Commensalism
C) Facilitation
- How has the trophic cascade mode helped explain the historic transitions in pacific help forest communities?
A) The longer days of summer increase the kelp forest size,
B) When sea otter numbers are abundant, they control the sea urchin populations that feeds on the kelp forest
C) the loss of sea otter populations leads to an increase in sea urchins and kelp forest populations.
D. The introduction of beavers greatly reduces the sea urchin populations that feeds on the kelp forest.
B) When sea otter numbers are abundant, they control the sea urchin populations that feeds on the kelp forest
An assemblage of populations of various species living close enough for potential interactions would be an example of?
A Biological Community
How a organism fits into it’s ecosystem or the specific set of biotic and abiotic resources and organism uses in its environment would be an example of?
An Ecological Niche
Differentiation of ecological niches that enable similar species to coexist would in a single community would be an example of?
Resource Partitioning
A niche that could potentially occupy a area but is unable to because of another species is called a….
Fundamental niche
If a species is actually occupies a niche spot it is called a……
Realized niche
Something that examines the number and variety of organisms would be an example of?
Species composition
The absolute number of a species is the?
Richness
The proportional representation of each species would be called the?
Relative abundance (evenness)
in regards to trophic levels, roughly how much energy stored as organic matter at one level will be converted to biomass at the next level?
~10%
in regard to trophic levels and stability, what level would impact the other the most?
Fluctuations at lower tropic levels are magnified at higher levels.
what caused the rapid decline of the sea otter populations in Alaska from 1990 - current
Killer whales learned how to hunt and kill Sea otters.
a species that exert a strong control on a community by their ecological roles but not necessarily their abundance would be a…
Keystone Species
How did Dr. Estes test the hypothesis that killer whales were hunting Sea otters?
- They looked at sea otter population ranges where killer whales were present and absent.
- in particular, two areas. 1 where otters were protected from predators and 1 where they weren’t.
The ____ _____ _____ of community organization proposes unidirectional influence from lower to higher trophic levels.
Bottom-up model
The presence or absence of mineral nutrients determines community structure, including the abundance of primary producers.
A) Bottom-up model
B) Top down model
Bottom-up model
The ____ ______ ______ (or trophic cascade model) proposes that control comes from the trophic level above.
Top-down model
In the case that predators limit herbivores, herbivores limit plants and plants limit nutrient levels.
A) Bottom-up model
B) Top down model
B) Top down model
What is the most realistic Trophic structure?
A) The food chain
B) the food web
B) the food web
A metric that is used to quantify species diversity within a community would be an example of which index? Consider that this model considers both species richness and the relative abundance.
Hint: (H)
The Shannon Diversity Index.
