Lecture 21-22 Flashcards
primary production
the chemical energy generated by autotrophs during photosynthesis and chemosynthesis
gross primary production
total amount of carbon fixed by autotrophs. controlled by climate as it its influenced by photosynthetic rates.
net primary production
the amount of energy captured by autotrophs that result in an increase in biomass
t/f NPP energy left over for plant growth and for consumption by detritivores and herbivores
true
leaf area index
leaf area per unit ground area
grassland and desert plants allocate more npp to roots because soil nutrients and water are scarce
true
NPP can not be estimate from GPP and respiration measurements
false it can
net ecosystem energy
the net change in co2 is gpp
NPP increases as precipiation increases
true
Npp increases with average annual temperature
true
secondary production
energy derived from consuming organic compounds produced by other organisms
1st trophic level
primary producers autotrophs produce the most organic matter in an ecosystem
2nd trophic level
herbivores that consume the autotrophs
3rd or higher trophic level
carnivores that consume animals from the level below
primary producers
autotrops
primary consumers
herbivores
secondary consumers
carnivores
tertiary consumers
carnivores
interaction webs
describe tropic and non trophic interactions.
t/f terrestrial ecosystems, only a small portion of the biomass is consumed, and most of the energy flow passes through the detritus
true
trophic pyramid
displays the amounts of energy or biomass in each trophic level
t/f
in aquatic ecosystems the biomass pyramid is inverted
bottom up view
resources that limit NPP determine energy flow through an ecosystem
top down view
energy flow is controlled by rates of consumption at the highest trophic levels
trophic cascades
trophic interactions that result in changes in biomass and species composition.
what may control the number of trophic levels
amount of energy entering primary production
frequency of disturbance
ecosytem size
community structure
the set of characteristics that shape communities
species richness
the number of species in a community
species evenness
relative abundance compared with one another
taxonomic affinity
all bird species in a community
guild
a group of species that use the same resources
functional group
species that function in similar ways
species accumulation curves help determine what?
when most or all of the species in a community have been observed
species composition
identity of a species in a community
trophic facilitation
a consumer is indirectly facilitated by a positive interaction between its prey and another species
competitive networks
interactions among species where every species has a negative effect on every other species
foundation species
dominant species
ecosystem engineers
organisms that create, modify, or maintain physical habitat for themselves and other species
interaction strength
measure of the effect of one species on the population size of another species
keystone can be top predators but are not always
true
redundant
having the same function as other species within a larger functional group
disturbance
events that injure or kill individuals
stress
abiotic factors that reduce growth, reproduction, or survival
subtle change
gradual turnover of dominant species due to competition
catastrophic change
large scale changes
succession
change in species composition over time
climax stage
the stable end point in succession that changes little.
primary succession
slow progression initial conditions are inhospitable colonization of habitats that have no life
secondary succesion
reestablishment of a community where some organisms have been destroyed occurs after fires/ storms
facilitation model of succession
early species change the environment in ways that benefit later species.
tolerance model
early species change the environment in ways that do not benefit nor harm later species
inhibition model
early species change conditions in negative ways that hinder later species
