Ecology final new material

Succession
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Terms in this set (70)
Succession
change in community composition over time following a disturbance
sere
distinct groups of species based on their functional characteristics
monoclimax or organismal concept of community development
Clements-succession proceeds through a series of intermediate stages called seres until a stable endpoint called a climax is reached.
individualistic hypothesis
individual responses to climatic variables
Gleason- more realistic
autogenic and allogenic environmental change
auto- living individuals can affect the successional trajectory (like trees growing taller)
allo- any abiotic factor that can affect successional trajectory (like saltwater inundation)
intermediate disturbance hypothesis
diversity will peak at an intermediate time since last disturbance
How do early and late successional species differ?
early plants- many seeds, small seeds, dispersed by wind, fast growth rate
late plants- few seeds, large seeds, slow growth rate
What are Connell and Slatyer's three models of succession? Give an example of each and use a graph to describe when you think each would occur.
inhibition- initial colonizers further colonization
tolerance- initial colonizers don't affect later species
facilitation- initial colonizers help later colonizers
Explain the difference between the organismal concept of communities and the individualistic continuum concept. Which do you think most accurately describes real communities and why?
individualistic hypothesis is more realistic
edge effect
different environmental conditions found on the border between habitats
species area curvelarger areas=more species, but eventually levels out/asymptotesisland biogeographycloser to mainland, more species. larger the island, more speciesecosystem functioningaggregate output that all individuals contribute togross primary productivitytotal rate of photosynthesisnet primary productivityrate of energy stored as organic matter after respirationsecondary productivityproduction of consumersstanding crop biomassproductivity as modified by herbivorycompensation depthwhere NPP (net primary production) is zeroassimilation efficiencythe proportion of energy ingested that is assimilatedtrophic efficiencysaid to be roughly about 10%. Pn/Pn-1Discuss the major ecological differences between edge species and interior species.edge species prefer the edges of habitats. they are species like shade intolerant trees, shrubs, vines.What are the two main food chains of ecosystems? Which is more dominant in terrestrial ecosystems and why?grazing and detritalExplain why energy is lost as it is transferred from one trophic level to another. What are the effects of energy loss on the biomass of different trophic levels?wasteWhat are the two important demographic variables that vary with the size of an island and its distance from a mainland?What are the two sides of the SLOSS debate, and how does the theory of island biogeography relate to the debate?single large verse several small habitat.Describe the effects of temperature, moisture, length of photosynthetic period, and nutrient availability on net primary productivity in terrestrial ecosystems.tropical rainforests have highest net primary productivityExplain why primary productivity is typically higher in coastal areas of the ocean than far from shore in the open ocean.gyres bring in nutrients, and runoff from land puts out nutrientsbiogeochemical cyclesflow of a substance from nonliving to living componentscarbon cyclenot balanced. atmosphere, oceans, sediments are reservoirs of carbon.retranslocationrecycling nutrients within a plantwater cyclebalanced.nitrogen cyclenot balanced. most nitrogen in the atmosphere is N2 (gas). nitrogen fixation makes N2 into bioavailable forms.ammonificationthe formation of ammonia or ammonium compounds through the bacterial decomposition of organic matternitrificationreduced nitrogen compounds (primarily ammonia) are sequentially oxidized to nitrite and nitratedentitrificationreturning N to the atmosphere by specific denitrifying bacteriaWhat is "missing carbon?" Was it found and where? Use the Gaia hypothesis and concept of tipping points to examine how terrestrial and marine ecosystems might respond to increasing atmospheric CO2.2 billion tons of carbon were missing from budget. found it in the trees in the tropics, that were growing faster than expected. this supports the Gaia hypothesisA relative deficiency in which step of the Nitrogen cycle would cause eutrophiciation? Explain how this can generate hypoxic conditions in a lake. How can it generate the "dead zone" found in the Gulf of Mexico?runoff of fertilizers, causes algae bloomswhy do diffuse effects in food webs occur?indirect effectsA negative indirect effect of one species on another through a shared predator isapparent competitionA decline in plant diversity with increasing resources can be explained byA shift to above ground competitionA decrease in Spartina following the loss of crabs is the result of bottom up processes.falseboth resistance and resilience can contribute tofood web stabilityabrupt changes in community structure or small transition zones between associations along an environmental gradient would provide evidence for theorganismic hypothesisMaximum sustainable yieldthe largest yield (or catch) that can be taken from a species' stock over an indefinite period.bycatchunintended catchhabitat fragmentationreduction total area of the habitat, increases amount of edge, reduces amount of interior. also isolates one habitat fragmentation from anotherinvasive speciesa non-native species that has a negative impactthe intermediate disturbance hypothesis suggests that:diversity peaks at intermediate frequencies, sizes, and time since last disturbanceare early or late successional species able to disperse seeds great distances and maintain a seed bankearlyin restoration, planting patches with more trees can _____________________ rate of succession byincrease, attracting birdsdiffuse effects would most likely be foundwhen disturbances do not occur too frequently or too infrequently (intermediate disturbance frequency)following the loss of vegetation due to a disturbance in a salt marsh, succession is facilitated by the invasion of salt tolerant fugitivestrueas patch size increases....species richness increaseswhy is energy lost as it is transferred from one trophic level to anotherrespiration, not all of it is consumed, generation of waste productsNPP refers tothe rate of energy storage as organic matter by autotrophs after respiration is deductedthe sloss debatewhether efforst should focus on conserving fewer but larger areas of land or oceanassimilation efficiencythe proportion of energy ingested that is assimilatedgross primary production, stability through time, and disease resistance can all measureecosystem functioningNH4 can be converted to atmospheric N2 bydenitrifiersthe water cycle consists mainly ofprecipitation and evaporationhow is the dead zone createdeutrophicationthe carbon reservoir that is increasing in acidity due to increased atmospheric CO2the oceanspecies accumulation curvecan be used to describe richness and evenesssince 600 million years ago, earths diversity has..increased (but shown several mass extinctions)3 main causes for modern species extinctionsoverexploitation, habitat fragmentation, invasive speciesscallop fisheries have collapsed in NC due tofishing down the food web, decline of sharks, top down controlapparent competitionone predator, 2 prey, both prey have positive affect on predator, and indirect negative affect on eachotherexploitative competition2 species using the same resource, therefore both have indirect negative affect on eachothercarbon fertilizationtrees grow faster in elevated CO2where do you see the fastest population growthhalf carrying capacity, K/2