Test 2 Flashcards

Question

2 "sources of slowing" for the growth of species 1

Answer 1

1. its own density 2. The density of the second species weighted by the second species relative impact

Answer 2

Biological invasions should be influenced by the degree of similarity between exotic and native species 1. Novel genera would be more successful invading than genera with native representatives. Prediction: greater differences, less competition, more success 2. Invaders that are more closely related to natives should be more likely to succeed, owing to similarities based on common ancestry. Prediction: greater similarities, greater competition, less success Test: Match the ancestral elatedness of the invader with those in the native community Trait over-dispersion: The presence of greater variability than would be expected based on a random model Supports H1 (novel hypothesis), with species more distantly related to the native community are most likely to invade Why: Less competition = easier invasion

Answer 3

The directional replacement in community composition through time, initially in response to disturbance but then regulated by autogenic processes (species influencing other species, and themselves).

Answer 4

- Communities altered by humans; characterized by new combinations of species and environmental conditions Message: outcomes of successions are not always predictable - Especially in terms of species composition and species richness - Predictability declines as scale gets smaller

Answer 5

A major agent of natural selection Kills or damages, affecting fitness - Tolerance traits - Avoidance traits - Prevention traits Catastrophic: Where all species are eliminated Non-catastrophic: some species persist

Answer 6

Not all disturbance are the same - Environmental Stochasticity - How predictable is the occurrence of disturbances - Intensity: Disturbance vary in their magnitude, duration, frequency, and interval

Answer 7

- Too much is too bad, too little is too bad - Predicts species diversity will be greatest when disturbances like fires, tornados, or hurricanes are of intermediate amount of time has passed after disturbance Predictability Matters - Anthropogenic change typically involves significant shifts in the intensity of disturbances, that are so frequent that they homogenize landscapes and thus highly predictable (lowering species diversity)

Answer 8

1. Follows the same rules as the ecological niche and environmental carrying capacity. - Environment acting on species (disturbance) - Species acting on the environment (autogenic processes affecting resource supply) 2. Follows the same rules as diversity regulation, with the blending on Type I and Type II diversity regulation - Dispersal: who gets there first - Competition: how the early colonists affect those that follow

Answer 9

Whatever shows up first stays - Ex. invasive “ice plant” colonizes disturbed coastal area of california. It has such high saline leaves that soil becomes too salty for anything else to grow.

Answer 10

The oak, to gain its present most northerly position in Northern Britain after being driven out by the cold probably had to travel fully six hundred miles, and this without external aid would take something like a million years - Based on average dispersal distance (janzen-conell) - How did it travel so far in so little time

Answer 11

- Rare long distance dispersal events, that tend to initiate primary succession - Colonization of Krakatoa - Empty space is quickly filled

Answer 12

1. How abiotic foctors shape the environment 2. How species shape the environment 3. Dispersal constraint on who get there first and in what abundance

Answer 13

Key problem: Rare events rarely seen or measured; requires indirect testing

Answer 14

Holocene tree migration from fossil pollen data - Spruce - Eastern north america - Date of first pollen appearance in lake sediments vs. closest previous appearance to the south Findings: 1. mean = -100 m/yr 2. Rare events > 1 km

Answer 15

- Northward expansion for forbs much slower than trees Hypothesis: unoccupied suitable (births>deaths) habitat remains Test: Transplant plant slow dispersers where they’re absent Outcome: 1. High success of transplants - growth and reproduction 2. 1000s of km2 of unoccupied by suitable habitat in northeastern North America for many species

Answer 16

Succession describes on-going transition, not progression towards a climax

Answer 17

1. Limiting environmental factors 2. Constraints on colonization

Answer 18

Any species can potentially colonize an area (as long ad they can disperse there) but the early colonists modify the location making it unsuitable for species arriving later

Answer 19

Resource control (exploitation competition)

Answer 20

Direct interaction (interference competition)

Answer 21

There can be multiple endpoints of succession at a given location not just one deterministic outcome Shaped by Three Factors 1. Environmental Change 2. Species Impacts 3. Dispersal

Answer 22

- Succession aways results in the same highly predictable outcome - Succession involves the orderly and highly predictable transition from one group of species ( r-type) to the next (K-type)

Answer 23

Lack of change over time

Answer 24

Remaining unchanged following disturbance

Answer 25

Returning to the reference state, after a temporary disturbance

Answer 26

An abrupt change in the functioning of a community often brought about by environmental change or the arrival of new species

Answer 27

Reversing the change may require different actions than what drove the change in the first place - Tough to go back to where you were

Answer 28

Kill prey during attack

Answer 29

Remove parts of many prey, rarely lethal

Answer 30

Consume parts of one or few prey, rarely lethal

Answer 31

Kill one prey during prolonged attack

Answer 32

Specialist - Consumes only one prey type Generalist - Consumes many prey types

Answer 33

non-linear

Answer 34

population processes

Answer 35

As the number of prey items increases, the number killed by the predator increases - Type I

Answer 36

As the density of rodents increases, the percentage of the population killed by weasels declines in a curvilinear fashion - Type II

Answer 37

As orey availability increases, the number of those found in the gut of the predator increases up to some threshold - Type II

Answer 38

As a previously rare prey species increases, predators slowly increase their consumption with prey density,

Answer 39

When more resources lead to less species and less production. - Initial growth then crash

Answer 40

Time spent foraging must be balances against other facests of growth and survival

Answer 41

1. Ease of capture 2. Handling time 3. Frequency within the prey population 4. Energy pay-off

Answer 42

Describes strategy that maximizes gain per unit time in systems where resources decrease with time

Answer 43

- Driven by the growth rate, size and nutritional quality of produces - Aquatic primary producers achieve faster growth rates and are more nutritious