EE BIOL 151A Midterm - Gorlitsky

ecology

the study of how organism exist, adapt, and interact within their environments

evolution

interactions of population dynamics, genetics, and natural selection

community

interactions between species and their influence on abundance and distribution

theoretical

using math, physics, and economics to answer ecology questions

conservation biology

ways to maintain diversity

restoration

restoration and management of ecosystems

landscape

features of landscapes, structures, and processes

ecosystem management

ecological, economic, and social goals to create a systems approach

environmental studies

multidisciplinary study of humans and the environment

theory of evolution

organisms better adapted to their environment will more likely survive and pass on traits to next generation

life zone

an area defined by climatic variables such as temperature, precipitation, and evapotranspiration

life zone variables

mean annual temperature, total annual precipitation, and ration of mean potential evapotranspiration

evapotranspiration

movement of water through plants; transpiration + evaporation

hadley cell

large-scale atmospheric convection cell

endemic

a species whose range is confined within a limited geographic area

biodiversity hotspot

biogeographic region that is both a significant reservoir of biodiversity and is threatened with destruction

savanna

open areas dominated by grasses and scattered trees

cloud forests

dense, species-rich ecosystems shrouded in clouds

jungle

a disturbed area where an abundance of sunlight results in a dense array of many plant species, often so thick that it is difficult to penetrate without the use of a machete

new world

north and south america

old world

africa and asia

decomposition

multiple organisms break down nutrients, which are released into a nutrient pool that are taken up by plants in the area

biogeochemical cycling

matter is recycled and shared

nutrient pool

amount of nutrients available

litter

fallen leaves, excrement, decomposition, and mineralization

leaching

process in which essential minerals are washed away by water

amazon soil

old, clay, poor, and oligotrophic

indonesian, hawaiian, and costa rican soil

young, volcanic, rich, and eutrophic

ultisols

well weathered

oxisols

deeply weathered, old, acidic, well drained

alfisols

sub-humid, sub-arid, neutral pH

inceptisols

young, rich, ~neutral pH, volcanic

entisols

young, rich, alluvial planes

npk

nitrogen, phosphorus, and potassium (macronutrients)

arrested litter

palms, epiphytes catch litter from canopy, grab nutrients before they hit the ground

nutrient scavengers

algae, lichens absorb nutrients from rainfall, leach from plants

apogeotropic roots

grow upward onto neighbor tree to absorb nutrients

rate of decomposition

X(t)/X(o)=e^-kt

X(o)=original litter

X=litter(t)

k=decomposition rate

endo-mychorrhizae

create vesicular-arbuscular, most common in tropics

ecto-mycorrhizae

associated with monodominance tree species, common in temperate regions

white rot

lignin is left over

brown rot

cellulose is left over

legumes

nodules in root system where bacteria live and convert N2 to NO3-

successional forests

originally, N is limiting, but as succession continues, P becomes limiting

nutrient use efficiency (nue)

amount of carbon fixed per unit of nutrient taken up

top down effects

large consumers alter the characteristics of a landscape

primary producer

takes solar radiation and converts it into carbohydrates

biomass

what is available to consumers

energy flow

movement of these organic compounds through the ecosystem

gross primary productivity (gpp)

total amount of photosynthesis accomplished (gpp=npp+r)

net primary productivity (npp)

amount of carbon fixed in excess of respiration (npp=gpp-r)

net ecosystem productivity (nep)

amount of carbon added to the system after respiration from plants, animals, and decomposers (nep=gpp-r(p)-r(a)-r(d))

respiration energy

metabolic need of the plant that radiates back to atmosphere as heat

carbon flux

rate at which carbon enters and exits an ecosystem

sink

greater amount of photosynthesis produced

source

greater amount of respiration produced

carbon sequestration

the process in which carbon is removed from the atmosphere and stored in reservoirs

leaf area index

one side of green leaf area per unit of ground surface

carbon fertilization hypothesis

suggests that forests act as sinks in response to the increase of carbon dioxide in the atmosphere

lianas

woody vines

geological changes to climate change

shrinking glaciers, melting permafrost, earlier snow melts, lakes and rivers warming, increase in coastal erosion

biological changes to climate change

shifts in leaf-out patterns, blooming dates, avian migration arrival, reproduction times, species distribution, ecological communities changes

biome

ecosystem that is distinctive with characteristic flora and fauna that is largely determined by climate

rainforest

dominated by broad leaf evergreens, with abundant rain

deciduous tropical forest

pronounced dry season and new growth at the beginning of new rain

forest gap

open area caused by disturbance that allows for abundant light to create fast growing, aggressive species

convergent evolution

organisms not closely related will evolve similar traits in response to similar conditions

emergent

towers over the rest of the canopy

buttresses

root that flares out from the trunk

lenticels

raised pores found in the stem of a woody plant that allows gas exchange between the atmosphere and the internal tissues

leaf flushing

when trees periodically drop a significant amount of leaves to reduce insect herbivory

seed dispersal

mechanism that allows offspring to escape the immediate environment of the parent

seed predators

destroy the seed when it is eaten

cauliflory

flowers and fruit produced from wooden trunks to facilitate dispersal

whorled

when two or more leaves are arranged at the node of a plant

latex

a milky liquid that coagulates in air

species richness

measure of how many species inhabit a particular area

species diversity

species richness and relative abundance

interaction diversity

complexity of interactions

latitudinal diversity gradient (ldg)

how diversity changes at different latitudes

evenness

measure of how equal populations are

alpha richness

number of species in a given area

beta richness

rate at which species change from one habitat to another within a region or along a gradient (ratio between alpha and gamma)

gamma diversity

total species diversity of a taxon in a broadly defined biogeographic region

cradle

tropics are uniquely suited to speciation, species generation is high, many young species

museum

speciation rates are not high but extinction rates are low, thus whatever evolves sticks around

productivity hypothesis

higher productivity areas have higher diversity because more species can obtain sufficient resources to maintain a viable population

climatic niche conservatism hypothesis

its harder to live in the extra tropics and fewer species can cope with the abiotic stresses and the earth has been tropical for most of its history

dobzhansky-macarthur phenomenon

the equatorial limits of species geographical ranges are usually due to biotic interactions

interspecific competition hypothesis

niches are narrower in the tropics because competition compresses them

predation hypothesis

predators are often generalist switching prey which permits the existence of competing similar species

top down theory - predators prevent prey species from becoming mono-dominate by switching prey based on abundance, hence rarity is safer

kinetic hypothesis

temperatures are greater in the tropics so metabolic processes are happening faster

red queen hypothesis

coevolution is like an arms race, evolution happens faster in the tropics because of coevolution

competitive exclusion

two or more species with identical ecological requirements cannot indefinitely coexist

niche partitioning

process by which natural selection drives competing species into different patterns of resource use, different niches

niche partitioning hypothesis

interspecific competition forces a species into increasingly narrower niches such that it is no longer at risk of competitive exclusion

storage effect hypothesis

seeds may be stored in the ground for prolonged time periods and thus have ample opportunity to reproduce years after the parent is no longer very productive

seed dormancy

seed that is unable to germinate in a specified period of time under a combination of environmental factors normally suitable for germination

negative density dependence

seed shadow effects likelihood of successful germination and growth increase with distance from the parent tree

intermediate disturbance hypothesis

if a disturbance is severe and frequent, few species will survive; if disturbance is rare and conditions are constant, then competitive exclusion will prevail; if disturbance is intermediate in intensity and frequency, many species may be supported and compete