Community Ecology Mr. Clark Bethpage HS

Key Concepts  Community structure  Roles of species  Species interactions  Changes in ecosystems  Stability of ecosystems

Community Structure  Appearance  Species diversity  Species richness  Niche structure  Edge effects

Species Diversity Species richness Species evenness Shannon- Weiner Index

Biodiversity  Latitude  Depth  Pollution  Theory of island biogeography Ants Birds

Ants Birds

Click to view animation. Types of two species interactions animation. Species Diversity 1, Latitude 80ºN ºN ºS 60 Latitude (a) Ants (b) Breeding birds

Number of individuals per diatom species Number of diatom species Unpolluted stream Polluted stream

High Low Rate of immigration or extinction Equilibrium number Immigration and extinction rates Number of species on island (a) © 2004 Brooks/Cole – Thomson Learning

High Low Rate of immigration or extinction Small island Effect of island size Number of species on island (b) Large island © 2004 Brooks/Cole – Thomson Learning

High Low Rate of immigration or extinction Far island Effect of distance from mainland Number of species on island (c) Near island © 2004 Brooks/Cole – Thomson Learning Immigration (near island) Immigration (far island) Extinction

Click to view animation. Area and distance effects interaction.

General Types of Species  Native  Non-native (exotic or alien)  Indicator  Keystone  Foundation

Keystone Species

sperm Eggs Sexual reproduction Fertilized egg development Organ formation Egg hatches Tadpole develops Into frog Young frog Adult frog (3 years)

Span worm Bombardier beetle Viceroy butterfly mimics monarch butterfly Foul-tasting monarch butterfly Poison dart frog When touched, the snake caterpillar changes shape to look like the head of a snake Wandering leaf insect Hind wings of io moth resemble eyes of a much larger animal

Predator Camouflage

Species Interactions: Competition  Interspecific competition  Predation  Parasitism  Mutualism  Commensalism  Resource partitioning

Predators

Defense Strategies Sharp Edges Poison Ivy Spines

Animal Defenses Bright Color Warning

Click to view animation. Gause's competition experiment interaction.

Resource Partitioning and Niche Specialization

Species Interactions: Predation  Predator  Prey  Prey acquisition  Predator avoidance

Symbiotic Species Interactions: Parasitism  Parasite  Host  Important ecological roles of parasites

Symbiotic Species Interactions: Mutualism  Pollination mutualism  Nutritional mutualism  Gut inhabitant mutualism

Oxpeckers and black rhinocerosClown fish and sea anemone Mycorrhizae fungi on juniper seedlings in normal soil Lack of Mycorrhizae fungi on juniper seedlings in sterilized soil

Click to view animation. Types of two species interactions animation.

Symbiotic Species Interactions: Commensalism  Species interaction that benefits one and has little or no effect on the other  Example: Small plants growing in shade of larger plants

Ecological Succession: Communities in Transition  Primary succession  Secondary succession  Pioneer species  Successional species

Click to view animation. Two types of ecological succession animation.

Primary Succession

Secondary Succession

The Rate of Succession  Facilitation  Inhibition  Tolerance

Ecological Stability and Sustainability  Disturbance  Climax community  Inertia  Constancy  Resilience  Precautionary principle

Table 8-1 Page 158 Table 8-1 Ecosystem Characteristics at Immature and Mature Stages of Ecological Succession Characteristic Ecosystem Structure Plant size Species diversity Trophic structure Ecological niches Community organization (number of interconnecting links) Ecosystem Function Biomass Net primary productivity Food chains and webs Efficiency of nutrient recycling Efficiency of energy use Immature Ecosystem (Early Successional Stage) Small Low Mostly producers, few decomposers Few, mostly generalized Low High Simple, mostly plant herbivore with few decomposers Low Immature Ecosystem (Late Successional Stage) Large High Mixture of producers, consumers, and decomposers Many, mostly specialized High Low Complex, dominated by decomposers High

Click to view animation. Resources depletion and degradation interaction