Ecology Exam 2 Study

The Levins model describes growth of a metapopulation: dp/dt = cp(1-p) - ep What part of this equation describes the availability of empty patches? (1-p) c e p

(1-p)

When a population is at carrying capacity... Birth rates are lower and/or death rates are higher than when the population is smaller. Competition is expected to be at its highest. Population size is stable. All of the above.

All of the above

A sky island animal species lives in oak woodlands on the mountains. This species cannot cross the desert in the valleys between mountains, however, it can use riverbeds to get between mountains. For this species, riverbeds are: A matrix A corridor A suitable patch

a corridor

Which is a proximate reason for the limit of a distribution? Lack of dispersal beyond the edge Extinction of edge populations before they can adapt Gene flow from the core

lack of dispersal beyond the edge

Match the following equations to the statements below. Not all equations must be used, and an equation may be used more than once. _____(3)Vital rates are changing as the population grows_____(3)The equation for density-dependent population growth_____(3)The logistic equation_____(1)A discrete time equation_____(2)Vital rates are constant; births and deaths are happening continuously

1.Nt+1 = λ Nt 2.dN/dt = rN 3.dN/dt = rN [(K-N)/ K]

Below are different examples of methods used to quantify dispersal distances. Match each one to whether it is a direct or indirect method for observing dispersal: _____(2) Allele for black coat color in wolves _____(1) Traps to collect seeds at different distances from a known mother tree _____(1) Radio collars on jaguars _____(1) Leg bands on birds _____(2) Fluorescent powder on insects

1. Direct 2. Indirect

Match the descriptions to the types of survivorship shown. _____(1) Most individuals survive to old age _____(2) Individuals die at a constant rate _____(3) Most individuals die at an early age

1. Type I 2. Type II 3. Type III

Match the definitions with the correct terms: _____(4)Movement of an entire population_____(5)The environments in which a species occurs_____(3)The locations in space where a species occurs_____(1)Movement of an individual away from other individuals_____(2)Spatial distribution of individuals at a small scale

1.Dispersal 2.Dispersion 3.Distribution 4.Migration 5.Niche

Match the following to their type of introduction: _____(2)Ballast water for ships_____(1)Landscaping plants_____(1)Fish introduced to ponds for recreational fishing

1.Intentional2.Accidental

Match the following terms to the descriptions below: _____(3)A species that grows to high abundance and becomes dominant in a community_____(1)A species that humans move beyond its natural dispersal abilities_____(2)A species that is unwanted / causes harm

1.Introduced species2.Invasive species: popular/legal definition3.Invasive species: ecological definition

Match the following terms to the descriptions below: _____(2)Introduced species has access to different ways of resisting enemies_____(1)Introduced species has access to different resources_____(3)Introduced species does not need to invest in resisting enemies

1.Novel niche2.Novel weapons3.Enemy escape

Demographic stochasticity... is variability introduced into realized vital rates because organisms must be born and die in whole numbers has a larger impact on small populations increases the probability of extinction all of the above

All of the above

The 'K' in the logistic equation... refers to carrying capacity indicates the size at which the population will stop growing is associated with the 'K' life history strategy all of the above

All of the above

Which of the following is an example of an invasive species according to the ECOLOGICAL definition? An introduced species of butterfly has become highly abundant in meadows An introduced weed gives people hay fever An introduced disease is decimating bird populations

An introduced species of butterfly has become highly abundant in meadows

Which of the following is NOT typically part of the process of making a climatic niche model? Collecting observations of the locations where a species is found, e.g. from museum data Determining the range of climate variables that occur where the species is found Collecting observations of dispersal distances for the species Identifying geographic locations with environments within the observed acceptable range of climatic variables

Collecting observations of dispersal distances for the species

There are many reasons small introduced populations might go extinct, and several of these reasons are related to population size. Which of the reasons below is NOT related to small population sizes: Stochastic extinction Environment outside the niche Positive density-dependence (Allee effects) Genetic drift

Environment outside the niche

The concept of Maximum Sustainable Yield (MSY) in fisheries assumes a particular type of population model. What is a reason that the model itself might be an incorrect model for the population? Environmental stochasticity Compliance with regulations Supply and demand

Environmental stochasticity

Which is a reason why our local Sky Islands harbor such high species diversity? Long distances between habitat patches, relative to dispersal High genetic diversity within species Gene flow among islands Adaptive plasticity

Long distances between habitat patches, relative to dispersal

If a fishery harvests mostly the largest fish in a population, what is a consequence that we should expect? Selection for smaller size Increased dispersal Demographic stochasticity All of the above

Selection for smaller size

You are studying a population and you wonder if birth rates are density-dependent. How would you test for that? Test whether birth rates are stable Test for environmental variation in birth rates Test for a relationship between birth rate in a year and population size in that year

Test for a relationship between birth rate in a year and population size in that year

How does a realized niche differ from the fundamental niche? The realized niche includes the effects of species interactions. The realized niche is based on climate variables. The realized niche is based on museum collections. The realized niche does NOT include the effects of species interactions.

The realized niche includes the effects of species interactions.

What does it mean when we say that a dispersal distribution has a 'fat tail'? Most dispersal happens at long distances There are rare, long-distance dispersal events Most dispersal is near the source Species never disperse very far

There are rare, long-distance dispersal events

For a population to be a metapopulation and to persist over time, it must include: extinction colonization open patches all of the above

all of the above

Marine reserves are a recent strategy for managing fisheries. Marine reserves involve which of the following? Areas set aside for no fishing Increases in population sizes within the reserve Dispersal from the reserve to areas outside of the reserve All of the above

all of the above

There are a number of problems with implementing the idea of Maximum Sustainable Yield (MSY) in fisheries. What is a practical problem? Bycatch (catching non-target species) Enforcement (preventing illegal fishing) Economics (supply and demand) All of the above

all of the above

We discussed how, during the last glacial maximum, much of North America was covered by glaciers and even non-glaciated areas were very different than they are today. Pollen deposits have revealed how tree distributions have changed in response. From this we can learn: That average dispersal distance can't explain the rate at which trees dispersed into newly suitable areas That long distance dispersal events are very important for explaining changes in distributions That distributions have changed over time and have not always been where we see them today All of the above

all of the above

Stochastic variation (environmental or demographic) in vital rates... happens only to small populations is density dependent always leads to a lower population growth rate than expected from the average vital rates always leads to extinction

always leads to a lower population growth rate than expected from the average vital rates

Density-INDEPENDENT population regulation is predicted to be associated with: A low resource environment A high competition environment An 'r-strategy' life history

an R-strategy life history

Is exponential growth discrete or continuous? Continuous Discrete Neither

continuous

If a population has a λ of 1.2 this year, and then λ of 0.8 the following year, the population is... growing declining stable unknown; there is not enough information to determine the population trajectory

declining

Which is an ultimate reason for the limit of a distribution? Lack of dispersal beyond the edge Genetic drift in small edge populations Low fitness beyond the edge All of the above

genetic drift in small edge populations

What does the "r" in this equation refer to? Nt = Noert

intrinsic growth rate

Maximum Sustainable Yield... is the maximum biomass of fish that it is possible to harvest changes with demand for a species of fish takes into account selection for small fish occurs at 1/2K in the logistic model

occurs at 1/2K in the logistic model

A sensitivity analysis... quantifies the change in population growth rate as a result of a change in a vital rate identifies the maximum sustainable harvest calculates the probability that a population will go extinct

quantifies the change in population growth rate as a result of a change in a vital rate