Term
-Breaks down cellulose efficiently, before cell contents pass through site of absorption
-Ruminants can synthesize their own proteins
-Cellulose breakdown is slow -> animal must be selective and choose high-N foods |
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Definition
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Term
-breakdown of cellulose not as complete, happens after site of absorption-digestion less efficient
-All amino acids must come from plants
-Faster digestion -> less efficient but animal can choose lower-quality foods |
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Definition
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Term
| Plants may reduce/escape herbivory through various strategies: |
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Definition
-Avoidance, e.g., masting to
overwhelm seed predators
-Tolerance: compensation
and over-compensation
-Defense |
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Term
| constantly produced. Tend to be C-based (e.g., condensed tannins in oaks) |
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Definition
| Constitutive or quantitative plant defense |
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Term
| upregulated during herbivore attack. Often N-rich (e.g., nicotine in tobacco and other alkaloids) |
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Definition
| Induced or qualitative plant defense |
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Term
| Plant apparency hypothesis (Feeny 1976): |
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Definition
-Defense depends on “apparency” – apparent plants are “bound to be found” by herbivores
-Non-apparent plants are rare or ephemeral
-Apparent plants have more defenses
-Apparent plants (e.g., oaks) tend to have quantitative defenses, non-apparent plants tend to have qualitative defenses |
|
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Term
| 2- Resource availability and plant antiherbivore defense hypothesis (Coley et al. 2005) |
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Definition
-Plants adapted to resource-poor environments are inherently slow-growing, resources are hard to replace, and tissues are worth hanging on to (long leaf life span) and worth defending
-Plants that have leaves with long life-spans should invest in quantitative compounds, whereas plants with short-lived leaves should favor qualitative compounds. |
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Term
| Ultimately, species richness at global scales is a function of three processes: |
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Definition
Speciation
Extinction
Dispersal |
|
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Term
| Diversification rate hypothesis |
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Definition
| there is more land area in the tropics, and it is more thermally stable Terborgh (1973), Rosensweig (1992) |
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Term
| Area and distance (=isolation) influence rates of immigration (recolonization) and extinction |
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Definition
| Theory of Island Biogeography |
|
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Term
| represents the change in species composition or turnover across the landscape, as one moves from one local community to another |
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Definition
|
|
Term
| Scaling down from γ (regional) to α (local) diversity: what drives local species richness? |
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Definition
The rate of supply of species from the regional pool (dispersal)
Abiotic factors (disturbance, temperature, etc.)
Biotic interactions (competition, predation) |
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Term
| The ability of a species to maintain itself in a community is determined by the..... that results in... zero net population growth (ZNPG). |
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Definition
| R*(limiting resource variable). |
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Term
| We’ve identified two sets of mechanisms to explain local species richness: |
|
Definition
-Resource ratios
-Spatial heterogeneity in resource ratios |
|
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Term
| “Unified theory of biogeography and relative species abundance “ |
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Definition
|
|
Term
| Local (α) diversity can be explained through various niche-based mechanisms: |
|
Definition
-Multiple limiting resources
-Spatial heterogeneity in resource ratios
-Resource partitioning |
|
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Term
| So why does predation enhance diversity in some cases and diminish it in others? |
|
Definition
| dispersal limitation and spatial heterogeneity |
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