2. Community Ecology Structure and Species Interaction Connor McNeil and Daniel Crawford

3. Community Structure (aka Spatial Distribution) Described by:  Physical Appearance: stratification, distribution, and relative sizes of population and species  Species Diversity (Richness): number of different species  Species abundance: number of individuals of each species  Niche Structure: number of ecological niches, how the resemble of differ from each other and how they interact

4. Difference in Physical Appearance  Terrestrial biomes consist of vegetation patches  Difference in size  Leads to boundries:  Sharp edges: distinct  Ecotones: Wider, more gradual transition zones

5. Distribution of Biodiversity Highest Biodiversity in Tropical Rain Forests  However, High Biodiversity and Low Species Abundance  Latitude: Latitude species diversity gradient : greater diversity in tropics, least at poles (terrestrial systems)  Depth: increases to 2,000m, then decreases, until ocean surface, which has high diversity (aquatic systems)

6. Species Interaction Competition and Predation  Intraspecific competition: members of the same species compete for resources  Territoriality: Patrolling, marking, and/or defending home/nest/feeding sight  Interspecific Competition: Competition between two or more species for resources

7. Competition  Interference Competition: one species limits another’s access to resources  Exploitation Competition: species have equal access to resources, but vary in speed and efficiency of exploitation.

8. Predator-Prey Relations  Predator feed directly on Prey  Individually harmful  However, through predation, Prey species limited in abundance and increased access to food and genetic stock improved  Use eyesight, speed, pack-hunting, etc  Pursuit and ambush

10. Prey  Naturally avoid being EATEN!!!  Speed, Detection, Protection, etc.  Camouflage, Mimicry  Chemicals: Poison, Irritation, Smell, Bad Taste  Enlargement

11. Symbiotic Species  Both species helped:  Parasitism*  Lichens, Bacteria, Algae *Can be considered special type of predation

12. Commensalism  One species helped; one unaffected  Ex: Raccoons and human garbage

13. Sources  http://www.bbc.co.uk/schools/gcsebitesize/science/edexce l_pre_2011/environment/populationsandpyramidsrev5.sht ml http://www.bbc.co.uk/schools/gcsebitesize/science/edexce l_pre_2011/environment/populationsandpyramidsrev5.sht ml  http://i2.wp.com/naturalunseenhazards.files.wordpress.co m/2010/09/raccoons.jpg http://i2.wp.com/naturalunseenhazards.files.wordpress.co m/2010/09/raccoons.jpg  http://3.bp.blogspot.com/_Y9- 9pUdrfsQ/TASYkDVUQLI/AAAAAAAAAXE/KStyyjVahy8 /s1600/IMG_3981.JPG http://3.bp.blogspot.com/_Y9- 9pUdrfsQ/TASYkDVUQLI/AAAAAAAAAXE/KStyyjVahy8 /s1600/IMG_3981.JPG  http://read.uconn.edu/PSYC3501/Lecture02/ http://read.uconn.edu/PSYC3501/Lecture02/  http://commons.wikimedia.org/wiki/File:Eucalyptus_forest _and_button_grassland.jpg http://commons.wikimedia.org/wiki/File:Eucalyptus_forest _and_button_grassland.jpg  http://www.life.illinois.edu/ib/453/ http://www.life.illinois.edu/ib/453/