Ecology: Species And Their Interactions (Community Succession And Biogeography)

Front 1

Define succession.

Back 1

The process by which species composition of a community changes over time.

Front 2

Define seral stage.

Back 2

Each stage of community change during succession.

Front 3

Define pioneer species.

Back 3

The earliest species to arrive at a site; typically are able to disperse long distance and arrive quickly at disturbed sites.

Front 4

Define climax community.

Back 4

The final seral stage in the process of succession; generally composed of organisms that dominate in a given biome.

Front 5

Define a chronosequence.

Back 5

A sequence of communities that exist over time and a given location.

Front 6

Define primary succession.

Back 6

The development of communities in habitats that are initially devoid of plants and organic soil such as dunes, lava flows and bare rock.

Front 7

Define secondary succession.

Back 7

The development of communities in disturbed habitats that contain no plants but still contain organic soil e.g., ploughed fields or forests uprooted by a hurricane.

Front 8

Define priority effect.

Back 8

When the arrival of species at a site affects the colonization of other species; often occurs through inhibition.

Front 9

Define tolerance.

Back 9

A mechanism of succession in which the probability that a species can become established depends on its dispersal ability and its ability to persist under the physical conditions of the environment.

Front 10

What are transient climax communities?

Back 10

A climax community that is not persistent; occurs when a site is frequently disturbed so a climax community cannot persist.

Front 11

What is a fire-maintained climax community?

Back 11

A successional stage that persists as the final seral stage due to periodic fires.

Front 12

What is grazer-maintained climax community?

Back 12

When a successional stage persists as the final seral stage due to intense grazing.

Front 13

What is landscape ecology?

Back 13

The field of study that considers the spatial arrangement of habitats at different scales and examines how they influence individuals, populations, communities and ecosystems.

Front 14

What are legacy effects?

Back 14

The long lasting influences of historical processes that affect the ecology of an area.

Front 15

What is a species-area curve?

Back 15

A graphical relationship in which increases in area (A) are associated with increases in the number of species (S).

S = cA>z

Front 16

What are stepping stones?

Back 16

Small intervening habitat patches that dispersing organisms can use to move between large areas of favourable habitat, useful for flying organisms that do not need continuous corridors to disperse.

Front 17

What is equilibrium theory of island biogeography?

Back 17

A theory stating that the number of species on an island reflects a balance between the colonization of new species and the extinction of existing species.

Front 18

What is the theory of island biogeography?

Back 18

Smaller islands should have higher extinction rates; islands nearer to a source of habitat should have higher colonization rates.

Front 19

Where do oceans have increased species richness?

Back 19

At lower latitudes.

Front 20

What are the hypothesises for patterns of diversity?

Back 20

1) Species are continually created over time and without limit; because tropical regions have not experienced glaciation therefore these areas have had more time to accumulate species.

2) The number of species in an area reflects an equilibrium between the processes of speciation and extinction.

Front 21

What is the energy-diversity hypothesis?

Back 21

Sites with higher amounts of energy are able to support more species and higher abundances of individual species.

Front 22

What is Laurasia?

Back 22

The northern landmass that separated from Pangaea 150 Mya and split into North America, Europe and Asia.

Front 23

What is Gondwana?

Back 23

The southern landmass that separated from Pangaea and split into South America, Africa, Antarctica and India.