Chapter 54 Community Ecology Community structure Community group
- Slides: 25
Chapter 54 ~ Community Ecology
Community structure Community = group of populations of different species living close enough to interact Richness (number of different species) and Abundance (each species numbers in a community) determine the Species Diversity of a community
Interactions Interspecific = interactions between populations of different species within a community Intraspecific = interactions within the same species
Interactions Competition = (-/-) interactions that occurs when individuals of different species compete for a resource that limits the growth and survival of each species
Competition Competitive Exclusion Principle = 2 species with similar needs for the same limiting resources cannot coexist in the same place Gause experiment
Competition evidence Resource partitioning sympatric (same location) species consume slightly different foods or use other resources in slightly different ways Ex: 7 Anolis lizard species perching sites in the Dominican Republic Character displacement sympatric species tend to diverge in those characteristics that overlap Ex: Darwin’s finch beak size on the Galapagos Islands
Niche Ecological niche = the sum of an organism’s use of biotic and abiotic resources in its environment; its “ecological role” Fundamental = the set of resources a population is theoretically capable of using under ideal conditions Realized = the resources a population actually uses Thus, 2 species cannot coexist in a community if their niches are identical Ex: Barnacle sp. on the coast of Scotland
Interactions Predation = (+/-) interaction between species in which one species, the predator, kills and eats the other, the prey May involve a keystone species/predator
Predation defense Cryptic coloration (camouflage) Aposematic coloration - (warning) Mimicry- superficial resemblance to another species
Mimicry Batesian= palatable/ harmless species mimics an unpalatable/ harmful model Mullerian= 2 or more unpalatable, aposematically colored species resemble each other
Interactions Herbivory = (+/-) interaction in which an organism eats parts of a plant or algae. Plants can’t run away to avoid being eaten, so they have adaptations that help: toxins, spines, thorns
Interactions Symbiotic Relationships Parasitism = (+/-) interaction in which one organism, the parasite, derives it nourishment from another organism, its host, which is harmed in the process
Symbioitic Relationships Mutualism = (+/+) interactions in which both species benefit Commensalism
Symbioitic Relationships Commensalism = (+/0) interaction between species that benefits one of the species but neither harms nor helps the other
Species Impact on Community Structure �Dominant species = highest amount of biomass (sum weight of all the members of a population) and most abundant �Keystone species = exert control on community structure; if removed, they have a large impact on food web and might even cause the collapse of the ecosystem � Effects on the ecosystem are disproportionate relative to their abundance � Examples: sea otter, dragonfly, gray wolf, elk, starfish
How the Wolves Changed Rivers Video
Species Impact on Community Structure �Species diversity – number of different species in a community and relative abundance of each �Trophic structure – feeding relationships of organisms � Food chains and webs
Evapotranspiration relates to the amount of water evaporation from soil and plants What relationship can you conclude from this graph about the water availability in an area compared to species richness?
Species Impact on Community Structure Invasive species = organisms (typically introduced by humans) that take hold outside their native range May not face the natural predators and agents of disease that would otherwise hold their populations at check ▪ Ex: Kudzu
Succession �Ecological succession = transition in species composition over ecological time �Process of predictable and sequential rebuilding of the ecosystem
Succession Video �Primary = begun in lifeless area where soil is not present �Ex: volcanic activity, retreating glacier, sand dune formation, forest on Stone Mountain �Secondary= an existing community has been cleared by some disturbance that leaves the soil intact �Forest fires, flooding
Succession �Primary succession Pioneer species – first organisms to inhabit a barren area ▪ Ex: mosses and lichen Climax community – final stable community �Secondary succession Ex: fires in Yellowstone National Park in 1988
Blowout after a storm and dunes will be rebuilt
Biogeographic factors Community diversity dependent on: Latitude of community: plant and animal life generally more abundant in the tropics, becoming less so moving toward poles Area of community: the larger the geographic area, the more species the community has Islands – isolation and limited size contributes to community diversity Rates of immigration and extinction influenced by size of island distance from mainland
- Chapter 3 section 1 community ecology
- Chapter 54: community ecology answer key
- 5 evolution and community ecology
- Chapter 54 community ecology
- Chapter 5 evolution and community ecology
- Ecosystems interactions
- Chapter 54 community ecology
- Chapter 4 section 1 population dynamics answer key
- Population vs community ecology
- Population vs community ecology
- Community ecology
- Definition of community ecology
- The definition of community
- Community ecology
- Levels of organization ecosystem
- Marine ecology
- Chapter 56 conservation biology and restoration ecology
- Phosphorus cycle pearson education
- Chapter 53 population ecology
- Chapter 52 an introduction to ecology and the biosphere
- Equilibrial life history
- Section 1 organisms and their relationships
- Chapter 2 principles of ecology test answers
- Principles of ecology chapter 2 section 1 answer key
- Chapter 4 population ecology answer key
- Chapter 53 population ecology