CHAPTER 26: COMMUNITY ECOLOGY
Interconnectedness of Species: Food Chains and Food Webs
Diversity
Beneficial Interactions Between Species
Concepts
Metapopulations in Patchy Environments
Predator-Prey Interactions
Community
boundaries
space
time
communities exist next to or within each other
some communities end and new ones begin
succession
climax community
human interaction
community restoration
mimic succession
damage
habitat fragmentation
habitat loss
corridors #
quantifying
species richness
species checklist
diversity of growth forms
diversity of trophic levels
diversity of alleles
Diversity and Scale
scale matters
larger areas are more diverse than smaller ones
more variation in habitats
larger populations
species-area relationship
S = cA^z
species abundance distribution
Diversity and Latitude
areas near equator have greater diversities
high-latitude areas have harsher conditions
less land is available in extreme latitudes
evolutionary differences
climate change over millions of years
temperate conditions are more recent
Predator Selection Among Multiple Prey
Competition Between Species
One Predator, One Prey
Apparent Competition
simplest system
paths
populations cycle
predator follows prey
predator over consumes prey
prey species disappears in area
both species stay at low, stable population sizes
predator's functional response
prey-dependent
consists of
feeding rate
time to find new individual
handling time
time to consume individual
zero growth isocline
population stability
models
Lotka-Volterra model
Rosenzeig-MacArthur model
more realistic
simplistic
straight isocline
curved isocline
paradox of enrichment
human interactions
maximum sustained yield
improving environment for one may result in loss of both
eutrophication
fixed effort harvesting
fixed quota harvesting
most animals eat a variety of plants and animals
factors
probability of encounter
decision to attack
probability that attacked prey will be successfully eaten
Optimal Foraging Theory
optimal diet model
botanists vs zoologists
zoologists put more focus on energy
exploitation competition
consume a shared resource
interference competition
restricts another's access to resources
leaf debris in winter
leafs blocking and using sunlight
invasive species
mutualism
both benefit
pollination
facilitation
one benefits while other is "unaffected"
not free
leads to cheaters
nurse plants
primary succession #
metapopulations
several populations interconnected by migration and gene flow
hard to model #
source habitat
sink habitat
migration corridors
fugitive species
assisted dispersal
food chain
simple
direct line of consumption
food web
more complex
shows multiple lines of consumption
energy flow web
keystone species
sea otters