Law of tolerance
most spp perform best w/ a narrow environmental conditions
matric forces
water tendency to adhere to walls
negative pressure
decrease plant water potential, created by water evaporation from leaves
Optimal foraging
predicts what/when/where animals eat
selection of energy based on minimal loss
hermaphadite
share male and female costs, low mobility, overlap in resource demands
distribution limits
geographical area restricting a spp distribution due to biotic and abiotic factors
3 patterns od survival tables
survivorship curves
type 1
graph = high mortality among older gen
- large invertebrates
type 2
graph = linear (-)
- birds, snakes
type 3
graph = die young
- seaturtle, invertebraes
Dispersal
increase or decrease in ppn density b/c of immigration/emmigration
impacted by:
- climate change
- food supply/dispersal range
dispersal down river/stream
Dispersal down river
colonization cycle = ppn maintain w/ interplay between up/down shifting
metapopulation
ppn of subppn that are connected w/ habitat requirements
BIDE dynamics
Birth Immigration Death Emmigration
biotic factors = density dependent
abiotic = density independent`
geometric and exponential ppn growth
geometric
- successive gen differ in size by constant ratio
- single gen per year
- gens no overlap
exponential
- overlapping ppn
- continuous
- instinsic rate of increase = per capita rate under idea conditions
logistic ppn growth
intravariation of spp
variation within spp
r selection
ppn growth rate, large value, fast
r spp
large ppn, fast growth, habitiat disturbance
k spp
small ppn, large, habitat near carrying cap (k)
ammensalism
spp1 negatively affected
spp2 neutral
neutralism
both spp neurtrally affected
forms of competition
competition evidence
ppn slow at increased density (k maxed)
density lowers faster than biomass increases (for plants)
Lotka-Volterra model
coexistence
- interspecific must be less than intra in both spp
coexistance factors
1 spatial heterogeniety in strength of competition
2 variation in spp competitive ability
3 competitive equivalence
4 non-equalibrium conditions (unstable)