final Flashcards
(16 cards)
what affects regional species richness
area and distance
area affects extinction
distance affects immigration
what 3 processes control species richness
speciation, extinction, dispersal
why are tropics more diverse? (3 theories)
rate, time, production/carrying capacity
distribution and abundance of species is determined by what?
dispersal and regional species pool
abiotic features
species interaction
what promotes coexistence?
disturbance, stress, predation and positive interactions
3 hypotheses of community diversity and function
complementary = linear redundancy = logistic (plateaus) idiosyncratic = different species more important
difference between NEE and NPP?
NEE takes into account heterotrophic respiration, so it is equal to the net carbon balance of the ecosystem, not just the net carbon fixation by the primary producers.
difference between NEE and NPP?
NEE takes into account heterotrophic respiration, so it is equal to the net carbon balance of the ecosystem, not just the net carbon fixation by the primary producers.
why doesn’t NEE increase with climate?
NEE takes into account the heterotrophic respiration, which increases with temperature
3 types of trophic efficiency?
consumption efficiency, assimilation efficiency, production efficiency
why do herbivores eat so little NPP
carnivores, plant defence, tissues that aren’t nutritious (like wood)
of trophic levels?
Addition of predators, omnivores changing their diets, more energy, frequency of disturbance, size of ecosystem
why does climate affect nutrient cycling?
with increasing climate and moist conditions, detritivores which are responsible for decomposition (which cycles nutrients back into the environment) work faster and have increased respiration rates.
What elements limit succession and when?
N limits succession at first, and then N&P limit succession, and then later, P limits succession
what are the threats to biodiversity?
Habitat loss Overexploitation Pollution Disease Invasive species Climate change
what properties of reserves are best?
Big, connected (sometimes), close, buffer zones, edge effect lessening (with a better shape)
