Community Ecology FINAL WOOOOOO

This will essentially be just an accumulation of all quizzes, as that's basically all it was last time

What are the three types of niche we discussed in class?

Abiotic, biotic, n-dimensional niche

Abiotic niche definition

Niche dictated by environmental factors

Biotic niche definition

Niche dictated by interactions

N-dimensional niche definition

Niche dictated by environment and interaction

What is the principle of limiting similarity in ecology

Species that are too ecologically similar will compete strongly and one may be driven to extinction

Describe the latitudinal diversity gradient

Diversity increases towards the equator, decreases towards the poles

Another diversity gradient we discussed?

Altitude

Three types of quantifying diversity: Taxonomic, _____, and ______

Phylogenetic, functional

Draw a species-area relationship, what is on the X and Y axis?

Increasing and flattens, area on x and species on y

What do we mean by alpha diversity?

Local diversity

What do we mean by gamma diversity?

Regional diversity

What do we mean by beta diversity?

Turnover, typically

Where is alpha diversity on an SAR?

Bottom left

Where is gamma diversity on an SAR?

Top right

Where is beta diversity on an SAR?

Circle in the middle

Which explanations have been proposed to account for why larger areas tend to support more species?

More habitats, chance, higher colonization rate, lower extinction rate

Which of the following are common explanations for why species diversity is higher in the tropics?

More stable climate over time, higher primary productivity, fewer glaciations

Closely related species are ____ likely to share diseases?

More

The theory of island biogeography is focused on the impacts of island distance and area on which two rates

Immigration and extinction

Supporting ecosystem service definition and example

Maintain fundamental processes - water purification, soil formation, pollination

Provisioning ecosystem services definition and examples

products that people get from ecosystems, raw materials, food production

Regulating ecosystem services definition and examples

Control natural phenomena - nutrient cycling, climate regulation, flood control

Cultural ecosystem services definition and examples

Non-material benefits people get, aesthetics, recreation and tourism

Two ways in which diversity may drive increases in productivity

Sampling effect, niche complementarity

Sampling effect definition

by chance, highly productive individuals are selected, individuals work better separately

Niche complementarity

two organisms’ niches work better than separate, provides overall increase in productivity

Diversity is generally thought to ___ productivity

increase

Diversity is generally thought to ____ nutrient uptake rates

increase

Diversity is generally thought to ____ ecosystem stability

Increase

Diversity is thought to generally _____ invasibility

decrease

How is it that you can have a constant (or increasing) species richness despite extirpations from a community?

Same factors that increase species richness also increase invasive species, invasives fill gaps left behind by extirpations

Do biodiversity experiments, theory, and observational studies agree

Sometimes

According to the study we discussed in class, is biodiversity per se usually the most important factor in driving ecosystem functioning in natural systems

No

Why is the exponential/Malthusian model of population growth unrealistic in most situations

Doesn’t account for carrying capacity, quickly overshoots feasibility

List factors that cause population growth rates to decline

Predation, competition, aggression, disease, accumulation of waste

Which of these might cause an Alllee effect

Shared predator defense, cooperative foraging, environmental modification

What does carrying capacity tell us about a population

Maximum number of individuals

Draw the typical shape of a Type 1 and Type 2 functional response curve

T1: diagonal line, T2: diagonal curve and flattens

Using this equation, explain two ways in which a species can increase its energy intake rate

Decrease handling time, increase energy gain from prey

In order for two species to coexist, aii __ aji

>

in order for two species to coexist, ajj ___ aij

>

Explain what the mathematical relations mean in biological terms

In order for two species to coexist, a species must limit itself more than it limits its competitor

In apparent competition with a single predator, the species that can tolerate the ___ predation will win

most

In competition for a single resource, the species that requires the ____ of that resource will win

least

Coexistence requires ____

a tradeoff, interspecific comp exceeds intraspecific

Briefly describe one of the tradeoffs we discussed in regard to coexistence

Temporal variation - organisms have to vary in their use of resources or reproduction over time

In the sonoroan desert, there are winter annual plants that preferentially germinate when a certain amount of rain is received, otherwise remaining dormant for years (decades in some cases)> Which type of coexistence mechanism is most likely?

Storage effect

Describe one coexistence mechanism that we discussed in class that might be important in your study system

Spatial variation - epibionts have to be acutely different in how they use the space available to colonize surfaces appropriately and still survive

In class we discussed the Lotka-Volterra models of competition were initially modified to instead model mutualisms. What unrealistic results did this lead to

Shoots to infinity, overshoots viable mutualisms

Why are L-V models of mutualisms incorrect?

Actual mutualisms have a limit to how much they can benefit another organism/population

In a network, what do nodes represent

Can represent an individual, species, etc

In a network, what do edges represent?

Linkages between species/individuals

What is the difference between a metaweb and a realized web

Metaweb is all possible interactions, realized webs are what species actually do/have been shown to do

What do we use a topological web for

Does food web interactions in space

Most data we have from networks comes from the _____ hemisphere

Northern

What happens to a network is one species is removed?

Depends on size of network, usually organism fills gap, but similar organisms in similar niches might be overexploited

What might happen to a network if a species is added

Increased competition between added and existing species, increased food availability for predators.

What is one context in which understanding networks could be important for decision making and why

Endangered species- specific interactions can dictate land and resource management scale

List two ways to decide which species are in the species pool in a given location

Fixed distance, dispersal ability

Why are dispersal kernels so hard to accurately measure

They reach a point of high risk/high reward, organisms hard to track and low data availability

List two ways we might infer environmental filtering

Dessication, frozen plants

List one way we might infer biotic filtering

Distance from competitor, grouping of solitary organisms, starving

Briefly describe three areas of research where you think community assembly theory might be useful

human resource use, ants, corals

write a haiku about community assembly theory

make something up

Draw a figure that shows the key ideas related to community assembly theory

Pop, abiotic filter, biotic filter, final pop

Indicate three areas on the figure that might be related to global change issues

Abiotic filter - increased temp

Biotic filter- less diversity

Final community - increased disease risk of meager pops

Explain two reasons why a focus on traits is more useful than a purely taxonomic approach

Can classify by larger groups or lifestyles, can more accurately predict impacts on communities

What makes something a “functional trait”

impacts growth, survival, or reproduction

What is an example of a trait that would be measured on the organ level

Digestion rate

What is an example of a trait that would be measured at an individual organism level

Calories consumed per day

What is an example of a trait that would be measured at a population level

Meat eaten per year

What are two of the ecosystem services the system you’ve been studying provide

Sea turtles = ecotourism, epibionts = water filtration

For each of the services you describe above, list two traits of the organisms in your system you think might underlie these services

Turtles = body size, macrofauna = cuter, internesting time = rarer to see

What is a metapopulation

Collection of connected populations

If we assume that the extinction risk of a species is negatively correlated with the number of patches occupied, list two ways we can reduce extinction risk

Decrease habitat destruction, more wildlife corridors

List two reasons why assisted migration may be necessary

Organisms move too slow, habitat change outpaces adaptation

List one trade-off that operates in patchy environments that can promote coexistence

Seed size vs plant size, dispersal vs fecundity, more seeds = more dispersal capability, lower fecundity

Propose one way of testing whether the tradeoff you listed is operating in a given system

Sample seeds from disturbed vs undisturbed patches, compare seed size vs plant height vs fecundity

Describe 4 traits (measurable at the individual level or below) that may be important for identifying how species may be impacted by one or more global change drivers (e.g., climate change, land use change, hunting, etc.). For each trait, explain why it is useful for understanding that particular driver

Body size, dispersal ability, generation time, food per day consumed

Briefly explain what we mean by “source” and “sink” populations.

source is births>deaths, exporter : sink is deaths > births, poor quality so doesn’t inherit overflow

Briefly explain the key ideas of neutral theory

Organisms are equal in birth rate, death rate, and dispersal. Space limiting, space occupied, number of individuals constant

Briefly explain one use-case in which neutral theory might be useful and one use-case where it might not be useful. (Bullet points or incomplete sentences are fine).

Comparing to species-area distribution, gives a null model/constant for dispersal comparison. Wouldn’t be helpful for analyzing long-term dispersal or species-level analyses