5.2: biogeographic concepts

Question 1

describe migration.

Answer 1

seasonal movement of organisms from one place to another. usually for feeding or breeding.

Question 2

what does migration do to biodiversity?

Answer 2

changes it as animals leave or appear

Question 3

migration results from…

Answer 3

the push from the lack of resources or the pull from an abundance in another area

Question 4

what are the two different types or migration?

Answer 4

• latitudinal migration: migration north or south of a position
• altitudinal migration: migration from one elevation to another

Question 5

what is the concept of island biogeography?

Answer 5

larger islands tend to have more species than smaller ones.

Question 6

define to term “island”

Answer 6

any habitat surrounded by an inhabitable area

Question 7

define speciation.

Answer 7

creation of new species through evolution

Question 8

what are the 2 different types of evolution?

Answer 8

• convergent: 2 or more unrelated species evolve in a similar way due to similar pressures
• divergent: population or one species disperses and evolves differently than the rest

Question 9

what is dispersal?

Answer 9

movement of an organism away from where it originated. decreases competition and allows more resources to be available.

Question 10

what are the different types of dispersal?

Answer 10

• intra-range dispersal: organisms disperses within its current geographic range
• extra-range dispersal: organism disperses outside its current geographic range. (often lethal)
• active dispersers: organisms that disperse under their own power
• passive dispersers: organisms that disperse due to an external force

Question 11

in terms of dispersal, define/describe the following:

• corridor
• biogeographic filter
• colonization
• invasion

Answer 11

• corridor: allow unrestricted movement between habitats
• biogeographic filters: barriers that allow certain types of organisms to disperse across them and other not
  (climatic {deserts and icecaps} and biological {predation and competition)
• colonization: successful establishment of a population in a new geographic region without human intervention
• invasion: successful and unwanted establishment of a population in a new geographic region as a result of human activity

Question 12

what is an ecological disturbance?

Answer 12

sudden event that disrupts an ecosystem

Question 13

what is succession?

Answer 13

the series of changes in an ecosystem that follow a disturbance

Question 14

what are the two different types of succession?

Answer 14

• primary: when life is completely removed form a landscape. soil and plants develop at the same time
• secondary: life survives the disturbance and ecosystems rebuild. (more common)

Question 15

what is a sere?

Answer 15

stage of ecological development

Question 16

what is a niche?

Answer 16

resources and environmental conditions that a species requires from an area.

Question 17

what is a habitat

Answer 17

exists within a niche; physical environment in which a species lives

Question 18

what are limiting factors?

Answer 18

prevent organisms from reaching reproductive or geographic potential; controls species niche.

Question 19

what are the various physical limiting factors?

Answer 19

• light: the amount of light that is needed by plants in order to grow
• temperature: extremes in temperature affect biological processes
• water: required by all organisms on earth

Question 20

what are various biological limiting factors?

Answer 20

• predation: consumption of one organism by another
• competition: interaction between organisms that require the same resources or anything that organisms needs to survive.
• mutualism: relationship between 2 species that benefits both of them

Question 21

what are ecosystems?

Answer 21

unit that includes living and non-living components within an environment.

Question 22

what is biodiversity?

Answer 22

number of living species in a region

Question 23

what is the difference between biomass and phytomass?

Answer 23

total living organic matter produced in a given area versus the total amount of plant matter only.

Question 24

what is the latitudinal gradient in biodiversity?

Answer 24

biodiversity is greatest at equator and smallest at poles

Question 25

what are species?

Answer 25

groups or individuals that naturally interact and can breed and produce fertile offspring

Question 26

what are biogeographic regions?

Answer 26

areas on a global scale in which organisms are isolated to physical barriers.

Question 27

what are the 8 biogeographic regions?

Answer 27

1. nearctic:
2. neotrophic
3. palearctic
4. oceanian
5. Ethiopian
6. oriental
7. australasian
8. antarctic

Question 28

what is the trophic hierarchy and its various tiers?

Answer 28

movement of energy and matter through the biosphere.

• primary producers: produce energy in the form of carbohydrates through photosynthesis.
• consumer: cannot produce its own food, must consume others
• decomposers: break organic material into simple compounds that re-enter the trophic system through plants.

Question 29

what is the food web?

Answer 29

movement of energy and matter through biosphere via ecological interconnection. only 10% of one levels energy will move onto the next level.

Question 30

what is the spatial hierarchy?

Answer 30

dividing biosphere based on spatial relationships.

individual>population>community&ecosystem>biome>biosphere

Question 31

what is a biome?

Answer 31

extensive expanses of vegetation types determined by climate.