Survey
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
Download Raven_ppt_ch04
Document related concepts
no text concepts found
Transcript
Chapter 4 Ecosystems and Living Organisms Evolution • Genetic changes in a population through time. • Occurs through natural selection Overproduction Variation Struggle for existence Differential reproductive success Evolution Darwin’s Finches Evolution Kingdoms of Life Biological Communities Rotting Log Community Biological Communities Succession: How Communities Change over Time Primary succession – Rocks Lichens Mosses Biological Communities Succession: How Communities Change over Time Primary succession – Rocks Lichens Mosses Grasses Shrubs Biological Communities Succession: How Communities Change over Time Primary succession – Rocks Lichens Mosses Grasses Shrubs Trees Biological Communities Secondary Succession Interactions Among Organisms Symbiosis – • one species living in or on another species • results from coevolution Interactions Among Organisms Symbiosis – Three types 1) Mutualism Without mycorrhizae With mycorrhizae Interactions Among Organisms Symbiosis – Three types 2) Commensalism Epiphytes Interactions Among Organisms Symbiosis – Three types 3) Parasitism Tracheal mites Interactions Among Organisms Predation – predators consuming prey Most common method: Pursuit and Ambush Interactions Among Organisms Animals that consume plants = herbivores Animals that consume animals = carnivores (can be further subdivided based on prey type, such as an insectivore) Interactions Among Organisms Defenses against predators: Plant defenses – • spines, thorns • leathery leaves • toxic chemicals Interactions Among Organisms Defenses against predators: Animal defenses – • armor, spines • toxic chemicals Interactions Among Organisms Defenses against predators: Animal defenses – • armor, spines • toxic chemicals • camouflage Interactions Among Organisms Competition – individuals attempting to utilize common resources • Intraspecific competition • Interspecific competition The Ecological Niche • An organism’s adaptations, use of resources, lifestyle, and habitat. Fundamental vs. Realized Niche Example: Tale of Two Anoles Green Anole Brown Anole The Ecological Niche Fundamental Niche of Green Anole Overlap Fundamental vs. Realized Niche Fundamental Niche of Brown Anole Brown anole out-competes green anole, therefore . . . The Ecological Niche Realized Niche of Green Anole Overlap Fundamental vs. Realized Niche Realized Niche of Brown Anole The Ecological Niche Limiting Resources The Ecological Niche Competitive Exclusion The Ecological Niche Competitive Exclusion The Ecological Niche Competitive Exclusion The Ecological Niche Resource partitioning Keystone Species • Single species that strongly influences an entire community. • Example: figs - frugivores depend upon fruit - usually avoid figs, but during certain times of the year, figs are only species bearing fruit - if figs were eliminated, many frugivores would die out Species Richness Number of different species in a community Forest ECOTONE Species Richness Grassland Where edge effect occurs Typically greater species richness Species Richness Species Richness and Ecosystem Services Ecosystem Forests, Grasslands Ecosystem services Purify air / water Produce / maintain soil Absorb CO2 Wildlife habitat Freshwater systems Moderate water flow Mitigate flooding Dilute / remove pollutants Drinking water Recreation Species Richness Species Richness and Community Stability Greater the richness = Greater the stability
Related documents