Metacommunities

Question 1

Lotka-Volterra equations

Answer 1

Equations that describe the relationships between prey and predators

Question 2

Issues with conventional stud of communities

Answer 2

Conventional views assume that communities are closed and isolated, however additonal ecological processes occur at larger scales.

Question 3

Metacommunity

Answer 3

Set of local communities linked by dispersal

Question 4

Metacommunity theory

Answer 4

Describes processes that occur at the metacomunity scale

Question 5

The importance of dispersal in coexistence

Answer 5

Strongly competing species can coexist regionally through constant interpatch dispersal, and a tradeoff between competitiveness and dispersal capabilities

Question 6

Mass effects

Answer 6

The occurrence of a species in local communities depend on an influx at a larger, regional scale

Question 7

Population

Answer 7

Individuals of a single spcies in a habitat patch

Question 8

Metapopulation

Answer 8

Set of local populations of a species linked by dispersal

Question 9

Community

Answer 9

Individuals of different species that interact in a defined spatial unit

Question 10

Metacommunity

Answer 10

A set of of communities in a region, which are linked by dispersal

Question 11

Microsite

Answer 11

A site capable of holding a single individual

Question 12

Locality

Answer 12

A spatial unit holding a community

Question 13

Types of patches (aka localities) and examples

Answer 13

1) Permanent patches (e.g., islands)
2) Temporary patches (e.g., fruiting bodies)
3) Permanent patches with indistinct boundaries and corridors (e.g., ocean currents)

Question 14

Region

Answer 14

A large spatial unit encompassing multiple localities

Question 15

Mass effect

Answer 15

A metapopulation dynamic involving a flow of individuals, which is affected by difference in population densities among patches

Question 16

Rescue effect

Answer 16

Constant recolonization reduces the chance of local extinctions

Question 17

Source-sink effects

Answer 17

Metacommunity dynamic in which immigration enhances populations size emigration decreases population size

Question 18

Colonization

Answer 18

Dynaiumc in which species become established in areas in which they were absent

Question 19

Dispersal

Answer 19

Movement of individuals: Immigration vs emigration

Question 20

Stochastic extinctions

Answer 20

Extinction events caused by disturbances beyond interacitons with other species

Question 21

Deterministic extincions

Answer 21

Mechanism in which populations become extinct due to biotic or abiotic interactions

Question 22

Metacommunity dynamics

Answer 22

Involve interaction of spatial and community mechanics

Question 23

Classic metapopulation (Levin)

Answer 23

Identical local populations with equal chance of colonization and extincion

Question 24

Mainland-island system

Answer 24

A system composed of extinction-resistant mainland populations and extinction-prone island populations

Question 25

Open community

Answer 25

A community that is open to immigration and emigration

Question 26

Closed comunity

Answer 26

An isolated community in which there is no immigration or emigration

Question 27

Patch occupancy model

Answer 27

Community model in which local populations are not modeled

Question 28

Spatially explicit model

Answer 28

Metacommunity model in which movement is influenced by arrangement and distance between patches

Question 29

Spatially implicit model

Answer 29

Metacommunity model in which arrangement and distance between patches do not influence movement

Question 30

The four paradigmal approaches to study metacommunities

Answer 30

1) Patch dynamic paradigm
2) Species sorting paradigm
3) Mass effect paradigm
4) Neutral paradigm

Question 31

Patch dynamic perspective to metacommunity dynamics

Answer 31

Metacommunity paradigm assuming all patches are identical and local species are modeled only by a tradeoff between dispersal and competitiveness

Empirically supported by butterfly metapopulations

Question 32

Species sorting perspective

Answer 32

Paradigm that explaines metacommunity patterns through environmental gradients, dispersal, and specialization to different patch types instead of dispersal/competitiveness

In this perspective, environmental gradients dictate the local demographies;

Empirically supported by plankton communties

Question 33

Mass effect perspective

Answer 33

A metacommunity paradigm that proposes species are rescued by immigrations, and that immigration enhance population sizes, while emigrations reduce population sizes.

Empirically supported by bacteria and protist communities, where they added corridors

Question 34

Neutral perspective

Answer 34

A metacommunity paradigm that assumes all species have equal competitive ability and attributes species patterns to random movement between communities; regarded as a null hypothesis against other community paradigms

Question 35

Problem with defining communities

Answer 35

Often don’t have discrete boundaries

Question 36

Problems with describing community processes with paradigms

Answer 36

1) Real ecological communties subject to both habitat ariability and stochastic dynamics
2) metacommunity behaviour depends on how species evolved

Question 37

Community-wide character displacement

Answer 37

States that locally existing species should be less similar to each other;

Tis view is controversial because communities with species that are more similar are less prone to invasions.

In nature, there’s evidence for both cases.