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Flashcards in Diversity and Abundance Deck (30)
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1

Machia Seal Island

tons of different types of warblers landed here because they were exhausted from migration and the diversity was insane

2

Species abundance curve

-most species are moderately abundant
-very few are super rare or super common

3

Relative abundance

-proportion each species represents of all individuals in the community
-consistent between habitats and taxonomic groups

4

Species diversity (definition and parts)

-variety of organisms that make up a community
-determined by species richness and relative abundance

5

species richness

# of different species in a community

6

What happens to diversity if your sample size is too small? What happens to diversity when you increase the sample size area?

-you underrepresent rare species and overrepresent common ones
-you find more species so diversity goes up

7

Shannon-Weaver Index

H = sum of pilnpi
where pi is the relative abundance

8

Abundance

how many individuals of a certain species

9

density

number of individuals per unit area

10

Relationship between nutrients and plant/algae diversity

-negative relationship
-reduces number of limiting nutrients
-causes competitive exclusion

11

Soons et al. experiments

-adding nitrogen reduced plant richness by 16%
-adding phosphorus did nothing

12

Two major biogeographical factors that affect species diversity

-lattitude (tropics are more diverse than poles)
-area (bigger area means more diversity)

13

Tree species per hactre

-Michigan = 10-15
-S.E. U.S. = 30
-Tropical Peru = 300

14

hot spots

-very diverse due to high number of endemic species
-Tropical areas near equator
-islands
-Mediterranean ecosystems

15

Why does latitude affect diversity (weather)

-dif latitudes have dif levels of sunlight and precipitation
-higher levels of evapotranspiration = more diversity

16

evapotranspiration

-evaporation of water from soil plus the transpiration of water from plants
-potential evaoptranspiration = potential water loss, assuming the presence of water

17

Why does latitude affect diversity (time)

-Tropical areas have had more time for speciation to occur (also more extinction)
-polar regions have had to restart due to glaciation

18

What kind of environments are good for diversity and how do phytoplankton/algae/diatoms reject this?

-complex environments = high diversity
-algae can live in simple communities if they have different trophic niches and have different ratios of nutritional needs

19

open ocean hot spots

-usually close to land
-only kinda follow the equator rule

20

What forms of life contribute the most to diversity?

-arthropods (especially insects)
-flowering plants
(prokaryote diversity is mostly unknown)

21

Biogeography

the study of the geographical distribution of species
-provides evidence for evolution
-an understanding of continental movement and modern species helps us know when and where these species evolved

22

Species Area Effect

- all other factors being equal, bigger area = more species
- S = cA^z
-S = # of species
-c = constant
-A = area
-z = how many species should be found as area increases

-in log-log plot of S vs A, z is the slope of the line through the data

23

Island equilibrium model

- richness = balance of immigration and extinction
- more S = less I + more E
- less A = less I + more E
- close to land = more I + less E

24

Wilson and Simberlof experiment

-Tested diversity of mangrove tree islands in Florida keys
-counted species
-fumigated island
-tracked increase of species over time
-equilibrium number returns to normal

25

Clements climax community

-thought that most communities were in a state of equilibrium and were governed by cliamate

26

Nonequilibrium model

-describes commuities as constantly changing after disturbance
-ex: Yellowstone forest (fire)

27

Intermediate disturbance hypothesis

-low and high levels of disturbance reduce diversity
-medium disturbance increases diversity
-high disturbance excludes slow-growing species
-low disturbance allows dominant species to exclude less competitive ones

28

Examples of intermediate disturbance hypothesis

-Townsend stream experiment
-diversity on boulders in intertidal zone
-prairie dogs open areas for colonization

29

Primary production and species richness

-PP increases with more species
-grazers increase PP (serangetti)
-increased growth rate due to low biomass (from being eater=n), don't need to self-shade, and smaller leaf size

30

Disturbance

-event that changes community, removes organisms, and alters resource availability