22 Flashcards
If you merge many Gaussian distributions, you start to get?
Higher frequencies among the tails with the same standard deviation and mean squared displacement.
Directed flights vs foray search?
•Higher mean
•Higher variance
•Higher standard deviation
All in directed flights compared to foray search.
Does directed flights or foray search have longer step lengths and turning angles more concentrated around 0?
Directed flights
If animals move by directed flight as its dispersal mode, what distribution will they converge to
Fat tailed kernels
What is the big problem proposed by Hutchinson?
How can you have a high diversity of phytoplankton that feed on the same recourses that coexist without competitive exclusion?
Selection, dispersal, drift, and speciation as potential reasons to Hutchinson’s problem? 4•
•Selection: Differences in fitness between individuals of different species. Diversity is maintained by density dependence that gives a rare species a positive population growth rate.
•Dispersal: Movement of organisms between locations in which species persist in a community because of processes at regional scale. Species diversity here is largely due to processes happening somewhere else. Persist here but niche somewhere else.
•Drift: Accidental changes in species relative abundance, unrelated to differences between species.
•Speciation
If interspecific competition is weak and intraspecific competition is strong, then rare species?
Have a higher chance of survival and persistence.
Selection hypothesis: If species 2 become really rare, then species 2 will?
Rebound (go up) since species 1 goes near carrying capacity and we are below species 2’s nullcline because interspecific competition is weak.
Do species strongly or weakly respond when weakly interacting competitors are removed?
Strongly
Hutchinson’s multidimensional niche space?
Each species occupies its own niche, so interspecific competition is much weaker than intraspecific competition. This stabilizing mechanism allows coexistence. The model is diagramed like this: when niches depend on temperature (length), food size (width), and branch density (height).
Dominance tolerance tradeoff?
That are good places and bad places, and everyone agrees which places are better and worse. Every species does better at a specific place.
Water use efficiency?
When there are a lot of water, you can take it up quickly
Three fundamental Tradeoffs in hydrologic niches in plants?
•Between water use efficiency (WUE) and nitrogen use efficiency (NUE)
•CO2 uptake vs water loss
•Safety vs efficiency in water transport (xylem architecture)
Selection in coexistence?
Coexistence occurs when stabilized mechanisms give an advantage to whichever species is rare.
At a global scale, plant diversity increases/decreases with increasing negative density dependence?
Increases
