Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
49 Cards in this Set
- Front
- Back
|
What local factors affect local species diversity?
(3) |
Competition, Predation & Physical Disturbance
|
|
|
Explain:
Intermediate Predation Hypothesis (What is the shape of it's "prey density vs. pred. intensity" graph?) |
IF the prey community is structured by competition with coexisting dominant and subordinate species
AND predators attack mostly the abundant competitively dominant prey THEN prey species diversity first increases then decreases as the intensity of predation increases. (Bell curve) |
|
|
Define:
Keystone Species |
one that strongly affects the community structure disproportionately to its own abundance.
|
|
|
Explain:
Intermediate Disturbance Hypothesis (What is the shape of its "Diversity vs. Disturbance Intensity" graph?) |
WHEN a community is structured by competition such that dominant species excludes subordinates
AND species diversity first increases then decreases during succession. |
|
|
What are the two hypotheses for understanding speciation on islands?
|
Habitat Variety Hypothesis
& Immigration-Extinction Equilibrium (IEE) Hypothesis |
|
|
Explain:
Habitat Variety Hypothesis |
Large islands have greater variety of internal habitats which allows for greater species diversity.
|
|
|
Explain:
Immigration-Extinction Equilibrium Hypothesis (aka "Theory of Island Biogeography") |
Larger islands support larger populations and therefore have lower extinction rates.
Species richness on islands is an equilibrium between immigration rate (decreases as species accumulate on island) and extinction rate (increases " " " " " ") |
|
|
According to the IEE Hypothesis, what factors control:
Immigration rate & Extinction rate |
Immigration rate varies with the degree of isolation. The closer the island to mainland the more species.
Extinction rate varies with island area. The larger the island the more species can be supported. |
|
|
What 3 hypotheses are used in determining the number of trophic levels in an ecosystem?
|
Energetic Constraint Hypoth.
Disturbance """"""""""""""""""" Evolutionary """"""""""""""""""" |
|
|
Explain:
Energetic Constraint Hypothesis (Bottom-up OR Top-down?) |
Only about 10% of the lower level energy (producers) is incorporated into the next trophic level.
Number of levels is determined by how much biomass the producers can create. (Bottom-up) |
|
|
Explain:
Disturbance Constraint Hypothesis |
Frequent disturbances prevent higher trophic levels from being established
"The animals follow the plants" |
|
|
Explain:
Evolutionary Constraint Hypothesis |
The existence of "super predators" is highly improbable because of morphological and behavioral adaptations.
|
|
|
What two hypotheses are used to determine the abundance of organisms in each trophic level?
|
Hairston, Smith, Slobodkin (HSS) Hypoth.
& Menge and Sutherland (MS) Hypothesis |
|
|
Explain:
Hairston, Smith, Slobodkin (HSS) Hypothesis (Top-down OR Bottom-up?) |
Carnivore abundance is controlled by competition, herbivore by predation, and plant by competition.
Relative abundances are HIGH, LOW, HIGH (Top-down) |
|
|
Explain:
Menge and Sutherland (MS) Hypothesis |
Omnivory occurs and upper predators have direct effects on all levels. Strong competition at highest level, moderate at middle, etc.
Relative abundances are HIGH, MODERATE, LOW |
|
|
Define:
Trophic Cascade |
Situation in which there is a strong top-down effect (predators strongly affect plants)
|
|
|
If a food web has an ODD number of trophic levels, are the primary producers in HIGH or LOW abundance?
|
Primary producers are in HIGH abundance
|
|
|
What are the assumptions, predictions, and examples of the HSS Hypoth and MS Hypoth
|
~Assumptions~
HSS: simple food web MS: omnivory is common ~Predictions~ HSS: high plant abundance (odd # trophic levels) MS: low plant abundance ~Examples~ HSS: otter-urchin-kelp MS: rocky intertidal areas |
|
|
Using ecological concepts summarize Oksanen et al's Hypothesis
|
Energetic Constraint
+ Trophic Cascade = Oksanen et al's Hypoth |
|
|
Explain:
Oksanen et al's Hypothesis (Top-down OR Bottom-up?) |
As the abundance of plants increases the number of trophic levels increases, and the importance of competition & predation at each level will alternate as the length of the cascade increases.
(BOTH Top-down & Bottom-up) |
|
|
What are the 3 forms of competition?
|
Interference Competition (direct)
A <- -> B Exploitation Competition (indirect) A <-........................-> B <+ -> Resource <- +> Apparent Competition ("Pseudo" or "False" comp.) <- +> Predator <+ -> Prey 1 <-.......................-> Prey 2 |
|
|
In terms of web stability, define:
- Persistence - Constancy - Resilience - Resistance |
Persistence: existence through time (YES or NO)
Constancy: variation through time (HIGH or LOW) Resilience: rate of return to original state after disturbance (functional) Resistance: capacity to remain undisturbed despite an environmental change (functional) |
|
|
Define:
- Resilience - Threshold - Regime |
Resilience:
capacity of an ecological community to absorb disturbance & environmental change, thereby remaining in the same regime and NOT crossing a threshold into a new, less desirable regime. Regime: a "stable state" community whose structure and function persists until a threshold is crossed. Threshold: level of disturbance or environmental change beyond which a rapid "phase shift" to a new regime occurs |
|
|
In terms of community ecology, define:
- Structure - Function |
Structure:
species composition Function: overall productivity |
|
|
Explain:
Rolling Ball Analogy (use the context of human influence on corals for an example) |
It's difficult to return to an initial regime if displaced by a disturbance.
Coral example.... Healthy state > macro algae state > sea urchin/barren state > ROCK |
|
|
Explain:
Complexity-Causes-Ecology-Stability Hypothesis |
More complex webs have more pathways therefore the ecosystem is much more stable.
Stability decreases with increased species richness and number of linkages, and increases as most linkages are near the top of the food web. TRUE for comparisons WITHIN the same community type |
|
|
Explain:
Environmental-Stability-Allows-Complexity Hypothesis |
Low levels of disturvance allows the evolution of complex but fragile webs.
Stable environments result in high persistence and high constancy. Following a disturbance there is low resilience. TRUE for comparisons BETWEEN different community types |
|
|
Define:
- Primary Productivity (PP) - Gross PP - Net PP |
PP:
rate of energy or carbon fixed by photosynthesis per unit area over time Gross PP: before plant respiration (Ps) Net PP: after plant respiration (Ps - R) also known as biomass in food web. |
|
|
What are the most limiting factors in each ecosystem:
- on land - in freshwater - in oceans |
Land:
water & temperature (also known as evapotranspiration) Freshwater: phosphorous concentration Ocean: light & nutrients (most productive in shallow coastal areas where upwelling or river deposits increase nutrients) |
|
|
What are the residence times of carbon in plant biomass on land & at sea?
|
Land: about 10 years (in large immobile vascular plants)
Sea: about 15 days (in small drifting phytoplankton) |
|
|
Define:
Secondary Production |
Rate of biomass accumulation of consumers (animals) per unit area over time
|
|
|
What two things limit secondary productivity?
|
Primary productivity
& Ecological efficiency |
|
|
What are the two equations for determining ecological efficiency?
|
= (net production of consumers)/
. (net production of consumed) = (Consumption efficiency) x (Assimilation efficiency) x (Production efficiency) |
|
|
What are the average, minimum, and maximum values for ecological efficiency?
|
Average = 10%
Minimum = 1% (endotherms, i.e. humans) Maximum > 30% (some zooplankton) |
|
|
What are the 3 transfer efficiencies that make up ecological efficiency?
Give the ranges for each |
Consumption efficiency:
biomass consumed by consumer ~1% defended prey to >50% undefended Assimilation efficiency: physiological rate; most biomass is either not eaten or becomes feces. ~15% herbivores to 80% carnivores Production efficiency: respirated carbon & heat loss; the % gross production. ~1% endotherms to >50% invertebrates |
|
|
Define:
Biomagnification |
The increase in concentration of lipid-soluble materials (i.e. Hg) from lower trophic levels to higher levels.
|
|
|
In terms of matter cycling, what two organisms are involved in decomposition?
|
Detritovores:
feed on detritus and excrete feces Decomposers: eat all organics and excrete raw nutrients |
|
|
Briefly explain the P, N, and S cycles...
What are their relative speeds? |
Phosphorous: SLOW
Nitrogen: FAST - Dead zones are caused around river deltas due to fertilizer run-off causing exponential phytoplankton growth/death, and the decomposers consume the oxygen in the water. Sulfur: MODERATE - volcanic emissions and fossil fuels lead to acid rain |
|
|
What are the 3 major causes for the recent climate disruption (specifically regarding CO2)?
|
1) More CO2 means warmer climate and a more acidic ocean
2) CO2 levels are the highest now than the last 800,000 years. Acceleration since the 1950s 3) Extra CO2 is from burning fossil fuels & defoestation |
|
|
Briefly explain the Carbon cycle...
(Including origins of fossil fuels) |
- Photosynthesis & respiration
- Fossil fuels = ancient photosynthesis - Coal = partially decomposed land plants - Oil = partially decomposed marine phytoplankton |
|
|
What was the annual carbon dioxide emissions between 2000 and 2009?
(Break that up between ocean, land, and atmospheric carbon) |
8.8 petagrams (1 Pg = 1 billion metric tons)
= 2.3 Pg in oceans (acidification!) + 2.4 Pg in land/plants + 4.1 Pg in atmosphere (warming of atmosphere & ocean!) |
|
|
Define:
Biomagnification |
The increase in concentration of lipid-soluble materials (i.e. Hg) from lower trophic levels to higher levels.
|
|
|
What are the 5 primary consequences of the increased carbon dioxide?
|
1) Melting of glaciers & ice caps (habitat & water loss)
2) Sea level rise & acidification (thermal expansion) 3) Extreme weather events (heat waves and hurricanes) 4) Altered plant & animal distributions (crop relocation, disease spreading, etc.) 5) Methane release from arctic ice and sea floor |
|
|
In terms of matter cycling, what two organisms are involved in decomposition?
|
Detritovores:
feed on detritus and excrete feces Decomposers: eat all organics and excrete raw nutrients |
|
|
Briefly explain the P, N, and S cycles...
What are their relative speeds? |
Phosphorous: SLOW
Nitrogen: FAST - Dead zones are caused around river deltas due to fertilizer run-off causing exponential phytoplankton growth/death, and the decomposers consume the oxygen in the water. Sulfur: MODERATE - volcanic emissions and fossil fuels lead to acid rain |
|
|
What are the 3 major causes for the recent climate disruption (specifically regarding CO2)?
|
1) More CO2 means warmer climate and a more acidic ocean
2) CO2 levels are the highest now than the last 800,000 years. Acceleration since the 1950s 3) Extra CO2 is from burning fossil fuels & defoestation |
|
|
Briefly explain the Carbon cycle...
(Including origins of fossil fuels) |
- Photosynthesis & respiration
- Fossil fuels = ancient photosynthesis - Coal = partially decomposed land plants - Oil = partially decomposed marine phytoplankton |
|
|
What was the annual carbon dioxide emissions between 2000 and 2009?
(Break that up between ocean, land, and atmospheric carbon) |
8.8 petagrams (1 Pg = 1 billion metric tons)
= 2.3 Pg in oceans (acidification!) + 2.4 Pg in land/plants + 4.1 Pg in atmosphere (warming of atmosphere & ocean!) |
|
|
What are the 5 primary consequences of increased carbon dioxide concentration?
|
1) Melting of glaciers & ice caps (habitat & water loss)
2) Sea level rise & acidification (thermal expansion) 3) Extreme weather events (heat waves and hurricanes) 4) Altered plant & animal distributions (crop relocation, disease spreading, etc.) 5) Methane release from arctic ice and sea floor |
