Biology 12000, Ecology Ii, Wall

Front 1

Is k-value a number of mortality of proportion?

Back 1

Proportion.

Front 2

What is mortality factor?

Back 2

Reason for mortality, eg weather, predation, etc.

Front 3

Which factors can affect the abundance?

Back 3

Secondary factors (weather, food, breeding sites, shelter, biotic factors) affect primary factors (BR, DR, immigration, emigration), and they affect population abundance.

Front 4

What are biotic factors?

Back 4

Interactions with other organisms: predation, parasitism, competition, disease.

Front 5

What are abiotic factors?

Back 5

Factors not connected with other organisms: affected by weather, direct (frost, flood, storms - directly kill the individuals) and indirect (weather affecting food supply and quality).

Front 6

Name two regulation forces of abundance.

Back 6

Biotic and abiotic factors.

Front 7

Regulation forces (biotic/abiotic) can affect an organism in two ways. Which ones?

Back 7

Density-dependent and density-independent ways.

Front 8

What is density dependent way of regulating abundance?

Back 8

Factors that act in a density-dependent manner have an effect on births and deaths which is directly related to population size.
Population size change -> BR/DR changes.

Front 9

What is density independent way of regulating abundance?

Back 9

Factors that act in a density-independent manner have an effect on births and deaths which is not related to the size of the population.

Front 10

In ideal world without predators, competitors, etc., what would be the relationship of Ro and r? And how would ploted growth curve look like?

Back 10

Ro =r.

Front 11

How does an exponential growth curve look like?

Back 11

Front 12

What is 'K' (not 'k')?

Back 12

Carrying capacity of species in an environment. It is maximum population size that the env. can sustain indefinitely. So that is a N of individuals that an env. can support without significant impacts to the given organism.

Front 13

Which type of limitation there has to be to allow the population to stabilise at its K?

Back 13

Density dependent.

Front 14

What is absolutely essential for a stability in a population?

Back 14

Density dependent regulation. In this graph the population would grow to infinite number. If DR higher than BR, go extinct.

Front 15

Describe 'big bang' reproductive strategy. r strategists.

Back 15

Front 16

Describe K strategists.

Back 16

Front 17

It is important to distinguish clearly between the determination a population’s characteristic (average) abundance and its regulation. Give an examples of these factors.

Back 17

Frost kills a lot of individuals, but it is not a regulating density dependent factor. Starvation would be, because more individuals available for limited amount of food, more will be starving.

Front 18

Describe exact compensation.

Back 18

BR, DR change precisely in relation to the change in density. We get smooth approach to the K and describe that as exact compensation.

Front 19

Describe overcompensation.

Back 19

BR reduce more than it needs to, DR increase more than it needs to for getting to the K, so we get a slope that is larger than 1.

Front 20

What is monotonic damping?

Back 20

A population that is damped monotonically will exhibit a smooth approach to its carrying capacity. This will happen if the population is either above or below its carrying capacity.

Front 21

What is damped oscillations?

Back 21

A population that is characterized by damped oscillations will overshoot and then undershoot the carrying capacity in sequence. The degree to which it undershoots or overshoots, however, will lessen with each timestep, until the population eventually settles on the carrying capacity.

Front 22

Describe stable limit cycle.

Back 22

A population that is characerized by a limit cycle will alternate between 2, 4, or possibly 8 population sizes in succession. The larger population size is above the hypothetical carrying capacity of the population. Density effects are strong. Resulting in a population far below carrying capacity during the next timestep. Under these circumstances density effects are low and the population size increases to above the carrying capacity once again. The population continues to overshoot and undershoot the carrying capacity in succession.

Front 23

What will happen if density dependence becomes too intense?

Back 23

Fluctuations of abundance become chaotic and may lead to extinction.

Front 24

In stable limit cycles what are the fluctuations driven by?

Back 24

Natural result of density dependence within a population (competition), not any extrinsic force (not parasitism, predation, etc.).

Front 25

What is undercompensation?

Back 25

When the BR decrease, DR increase, but not enough to reach K. In this case it wouldn't stabilize the population, but it would slow it down, without reaching K.

Front 26

What is resilience?

Back 26

The ability of the population to bounce back to its density dependent regulated characteristic level of abundance.

Front 27

What is the only way we can change the characteristic average level of abundance of the population?

Back 27

By reducing the intensity of density dependence. If we just increase N of indiv., they will soon die because population is under density dependent regulation.

Front 28

What are coupled oscillations?

Back 28

Linked oscillations in the abundance of predators and prey or host/parasitoids. Time delayed cycles.

Front 29

Name types of interactions between organisms.

Back 29

Mutualistim,
Commensalism,
Competition,
Parasitism, predation, herbivory.

Front 30

What is commensalism?

Back 30

Type of interaction between organisms, where one species benefit, one is unaffected.

Front 31

What are metapopulations?

Back 31

Metapopulations consists of a group of spatially separated populations of the same species which interact at some level. Some populations of species extinct, decrease, some increase, and there is migration between these populations.

Front 32

How do some animals maintain a constancy of abundance despite fluctuations in the numbers of prey?

Back 32

Prey switching.

Front 33

What is interspecific competition?

Back 33

Competition between the species.

Front 34

What is intraspecific competition?

Back 34

Competition inside one species.

Front 35

Finish the sentence:
Generally competitive interactions are:
-
-
-.

Back 35

- symmetrical - have to affect both individuals;
- necessitate spatial and temporal co-occurrence,
- increase in intensity as the density, phylogenetic similarity, and niche overlap of competing species increase.

Front 36

Name two processes of competition.

Back 36

Exploitation competition (for a limiting resource, when competitors do not interact directly) and
Interference competition (directly between competitors, eg for a mate).

Front 37

Name competition outcomes.

Back 37

Contest com. (changes in BR, DR which exactly mirror the change in the population and the population will come up to its K and be stable in it. Eg large pop -> more competition -> proportional change in B/D rates.)
Scramble com. (Individuals all compete for a resource, they exhaust it and massive increase in DR and decline in BR, pop. crushes suddenly.

Front 38

Different types of organisms (r/K life histories) may be associated with a particular types of competition. Give examples.

Back 38

Stable environment:
K-selected organisms – higher competitive ability – specialists – contest outcomes

Unstable environment:
r-selected organisms – lower competitive ability – generalists – scramble outcomes

Front 39

Describe the competitive exclusion principle.

Back 39

A single niche can only carry a single species. Evolution for specialization to particular niches. Over evolutionary time – spp become specialists, niche separation due to competition.

Front 40

What is apparent competition?

Back 40

Front 41

What is Community ecology?

Back 41

Community ecology is the study of the interactions that occur among groups of species coexisting within a region or habitat.

Front 42

Explain holistic approach of community ecology.

Back 42

Holistic concept: the view that communities are superorganisms ; the product is greater than the sum of the parts; unique characteristics that can be understood only as a whole.

Front 43

Explain individualistic concept of community ecology.

Back 43

Individualistic concept: the idea that communities are merely functions of populations, and are not organized in any way.

Front 44

What is stochasiticity?

Back 44

The quality of lacking any predictable order or plan, chance affects, random effects within the communities that we see in patches.

Front 45

What are multi-species community characteristics?

Back 45

Diversity,
Abundance and dominance,
Community stability,
Community structure.

Front 46

Tropical habitats support more species than do temperate and polar areas – why?

Back 46

Ecosystem persistence – a lot of time for adaptation, speciation.
Environmental stability - specialists, no strong seasonal effects.
Spatial heterogeneity (greater structure) – complexity – more niches for diff. organisms to specialise in.
Productivity – greater productivity = greater diversity.

Front 47

We can assemble ecological pyramids in terms of which three things?

Back 47

Energy flow through ecosystems, biomass, numbers of organisms.

Front 48

What is dictating the abundance and diversity in tropical environments?

Back 48

Productivity.

Front 49

Compare diversity and abundance of species in tropical and temperate environments.

Back 49

Tropical areas tend to have more species, but these species also tend to be rarer.
There are fewer species in temperate areas, but those fewer species tend to be more abundant (a relatively few species "dominate" the landscape) and they have larger geographic ranges than those in tropical areas (where species are more numerous, but each one is less abundant and has a smaller average range size).

Front 50

In general, in which habitats the diversity of species will increase?

Back 50

In stable and high productivity habitats.

Front 51

Why stable, high productivity habitats have high diversity of species?

Back 51

In general, species diversity will increase in stable and high productivity habitats.
This will result in increasing potential for competitive, parasitic, and predatory interactions ;
Specialists, narrower niche breadth.

Front 52

What is a keystone species?

Back 52

A keystone species is one whose presence or absence, or substantial increase or decrease in abundance, profoundly affects other species in the community.

Front 53

When a species are considered as keystone species?

Back 53

Keystone species must have a large and consistent impact on the dynamics of other species. Even a disproportionately large impact may be inconsistent if the species is very rare.

Front 54

What is thought when talking about stability of community?

Back 54

The ability of a system to bounce back to its original state after being disturbed
OR
how resistant the system is to change in the first place.

Front 55

Name the effects of a change (in abundance, or presence vs absence) of one species on another.

Back 55

Direct effects,
Indirect effects,
Cascading effects.

Front 56

In the effects of a change (in abundance, or presence vs absence) of one species on another what is thought by cascading effects?

Back 56

Cascading effects are those which extend across three or more trophic levels, and can be top-down (predator --> herbivore --> plant) or bottom-up (plant --> herbivore --> predator).

Front 57

Explain redundancy hypothesis.

Back 57

The Redundancy Hypothesis:
species redundancy enhances ecosystem resilience - assumes that more than one species performs a given role within an ecosystem.

Front 58

Explain the Rivet hypothesis.

Back 58

The Rivet Hypothesis:
Removing species weakens the stability, but if a critical number of species are lost, the system then collapses.

Front 59

What is community structure affected by?

Back 59

Seasonality (important intemperate habitats),
Succession (may be cyclic, eg fire, earthquakes), pushes community down to the beginning.

Front 60

Name applications of community ecology.

Back 60

Conservation biology: how to protect species, and to design, and monitor nature preserves.

Restoration ecology: how to restore or re-create natural communities.
Biomonitoring: determining the degree of pollution or other stress by studying ecological communities.
Landscape ecology: the study of the structure and function of a landscape composed of interacting communities.