terms Flashcards
carrying capacity
number of individuals/biomass of a species that an ecosystem can support
Ecologically functional
species that is sufficiently abundant to have a significant impact on other species in a ecosystem
succession
gradual process of change in species composition, vegetation structure, and ecosystem traits following a disturbance
guild
group of species at the same trophic level, eg. PP, secondary consumers, carnivores, omnivores, detrivores
Food chain
feeding relationships between species at different trophic levels
food web
network of feeding relationships between species at different trophic levels
keystone species
species with disproportionate impact (relative to biomass/numbers) on ecosystem
Keystone resources
crucial resource in ecosystem (eg. waterhole)
Niche
visualized as an n-dimensional hypervolume where the dimensions are environmental conditions and the resources that define the requirements of an individual, or a species to practice its way of life
ecosystem integrity
the state of an ecosystem when it is complete, fully functional and has not been damaged by human activity
ecosystem resistance
the ability of an ecosystem to remain at the same state despite ongoing disturbance
ecosystem resilience
the ability of an ecosystem to return to its original state following disturbance
redundant species
removal of this species has minimal impact on ecosystem structure/function (functional redundancy)
species richness
number of species in an area
relative/absolute abundance
patterns in the number of individuals of each species
species diversity
some amalgamation of species number and their relative abundances (richness and diversity are often synonymous)
alpha diversity
a local measure of diversity, often # of species per unit area in a given habitat/ecosystem (eg. # of mussels in a 2X2 mussel bed)
beta diversity
the difference in species composition between habitat types or ecosystems (eg. 2 species shared between habitats, high when there is a low overlap in species composition)
gamma diversity
total regional diversity made up by alpha and beta diversity components (gamma = alpha*beta)
Eveness
similar abundances among species
dominance
uneven distribution of abundances
island biogeography theory
higher extinction rates on small islands, extinction rates increase with more species, higher rate of immigration on islands close to mainland, immigration rate declines with more species
biodiversity
variety of life in all manifestations
variation among living organisms across habitats and taxonomic scales, as well as the ecological complexes of which they are a part
genotype
unique combination of alleles possessed by an organism