Term
| What is the definition of communities? |
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Definition
Assemblages of speciesfound in the same area and presumably interacting.
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Term
| What is the term used for the physical structure and growth form of dominant organisms? |
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Definition
| Physiognomy, usually the plant community to describe the biome. |
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Term
| Give examples of physiognomy. |
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Definition
Forest: Trees
Chapparal: Shrubs
Savannas: Grass
Tundra: Lichens and dwarf shrubs |
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Term
| Define abundance and density. How would one solve the total number of individuals in a community? |
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Definition
- The number of individuals of a given species in the community.
- the number of individuals per unit area = ni for species i
- to solve the total number of individuals in a community is to take the sum of density.
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Term
| Define Relative abundance and give the equation. |
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Definition
- proportion of a given species in a community = pi
pi = ni/sum(ni)
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Term
| What is the term for the total number of different species in a community? |
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Definition
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Term
| What is the term for relative abundance and species richness combined into a single parameter? Give an example |
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Definition
species diversity
e.g Shannon-Weaver Index (H') |
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Term
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Definition
| Those species assumed to be most important ecologically. |
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Term
| What are 5 different ways that may determine a dominant species? |
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Definition
- greatest primary producer
- greatest impact on ecosystem
- greatest biomass
- most numerous
- most frequent occurrence across sample
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Term
| In plant communities, what are the three measurements used in combination to measure dominance? |
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Definition
1. Relative Abundance; pi = ni/sum(ni)
2. Relative dominance; total dominance (basal area) / total dominance (basal area) of trees of all species
* basal area= pi(diameter/2)square then take the sum
of each species per unit area = absolute basal area
3. Relative Frequency; record percentage of plots in which the species was found. |
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Term
| What are the 3 measures of the importance values? |
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Definition
- % relative abundance
- % relative dominance
- % relative frequency
The sum of the above which each is based on 100, the value is scaled to 300. |
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Term
| What is community development? |
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Definition
| plant community can be relatively predictable and much reflects the old view that a community, like an individual organism, has it's developmental stages |
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Term
| What is the relationship of plant and animal community over time? |
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Definition
| They are parallel w/ each other as changes occur. |
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Term
Describe some species of animals that can be found in Grass and shrub, shrub tree, opening, low tree, and high tree.
What animal can live in all areas? |
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Definition
Grass and shrub: cotton tail rabbit and meadow mouse
shrub tree: white-tail deered,
opening: red squirrel and robins
low tree: white footed mouse
high tree: red fox
- Short tail shrew |
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Term
| What is primary succession? Give examples |
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Definition
occurs in a habitat that never previously supported a biological community.
e.g lava field, bare rock, sand dune. |
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Term
What is secondary succession?
Give examples. |
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Definition
Take placed on a habitat that have been disturbed, but had previously supported a biological community.
e.g. fire, floor, landslide, human clearing of land. |
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Term
| Does secondary succession or primary succession occur more rapidly and why? |
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Definition
| Secondary succesion occurs more rapidly due to the presence of seeds, undamaged roots and a developed soil. |
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Term
| How long is the range of succesional time in plant communities from colonization to the climax community? |
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Definition
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Term
| How long is the climatic change in a community? |
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Definition
| hundreds of years to tens of thousands of years |
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Term
| What is the time frame of continental drift? |
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Definition
| 100 to several hundreds of millions of years |
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Term
| Typically, there is a predictable pattern of species colonization and replacement, what is it? |
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Definition
| beginning with r-selected species, or pinoeer, than replaced by species that arrive later. |
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Term
| What happens after communities stop replacing one another? |
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Definition
| Community is at it's climax, where it continues to perpetuate itself until the next disturbance or change of climate. |
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Term
| Secondary succession occured in the Carolina Piedmont. The first year crabgrass Horseweed, but what plant was dominating during climax? |
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Definition
| The hardwood oaks dominated. |
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Term
| R-selected species during succession have special properties that enable them to survive. Do they survive during early or late succession and why? |
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Definition
| They survive during early succession, because they are able to disperse quickly and live in severe environments. |
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Term
| What is autogenic succession? What is the process called? |
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Definition
The activities of the pioneer, or r-selected, species enables the community to thrive, therefore, the changes are caused by the activities of the community itself.
The process is called th Facilitation Model |
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Term
| What is the inhibition model? |
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Definition
| The activities of one species may inhibit the colonization of another species. |
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Term
| What is Allogenic Succession? |
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Definition
Driven by changes in the physical environment
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Term
| Lake and pond succession is driven by both allogenic and autogenic forces, why? |
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Definition
| Silt and debris can enter due to the breakdown of rocks, also wind and water errosion of the terrestrial landscape. |
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Term
| What does the deterministic succession model propose? Give an example |
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Definition
There is one final cliax community for a given prevailing environment, the climatic climax.
e.g In a temperate deciduous forest it is dominated b Beech-Maple or Oak-Hickory Forest
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Term
| What other factors besides climate can be a role in succesion? |
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Definition
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Term
| What is the Processes of Succesion? |
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Definition
1. Colonization of an ope habitat
2. Site Modification
3. Continuing colonization by new species
4. Competition between earlier and later colonizers.
5. Community Changes
6. Futher Site Modification
7. further colonization and future community change
8. Climax community |
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Term
According to Clements, it does not matter if you begin as primary or secondary succession, because both will end up with the climatic climax.
Explain how succesion in a hydric community and xeric community should end in a mesic communit using specific examples. |
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Definition
Hydric community: Bog lakes in Michigan
Xeric community: dry dunes in Michican and Indiana
both communities will end up as a
Mesic community: dominated by beech and sugar maple |
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Term
| what are the thhree layers in water? |
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Definition
epilmnion: top surface
Metalimnion: middle surface
Hypolimnion: lower surface |
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Term
| What are the trends typically during succession via reproduction? |
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Definition
| R-selected early than K-selected later |
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Term
| what is competition-colonizatiom trade-off?a |
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Definition
| a life history trade-off btw high reproductive potential and colonizing ability vs. competitive ability |
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Term
| A trend seen is that species richness/diversity increases with succcesion. Why is that? |
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Definition
| Ecosystems become structurally more complex leading to larger numer of species. |
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Term
| When is maximum diversity found during succession? What is the hypothesis called? |
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Definition
| Prior to climax stage of succesion; intermediate disturbance hypothesis |
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