1. Ch 3.1 Communities Limiting Factors restrict –Existence, –Numbers, –Reproduction, or –Distribution of organisms

2. Ch 3.1 Communities Limiting Factors include –Density-dependent (4.1) Disease, competition/space, predators, parasites, food –Density-independent (4.1) Natural disasters, temperature, chemical pesticides, soil chemistry – Note: ranges of tolerance www.tpwd.state.tx.us

3. Ch 3.1 Communities Limiting factors can be direct or indirect –Lack of water restricts growth of grass effects number of seeds produced, –Mice go hungry, some die –Hawks have less mice to eat, they die www.sphotography.com/images/HAWK%20OWL%20EATI...

4. Ch 3.1 Communities Primary Succession –No living organisms –No soil –Causes: Volcanoes and flowing lava –Pioneer species – the first species to colonize (ex. lichens) –start to form soil

5. Ch 3.1 Communities www.cas.vanderbilt.edu/bioimages/ecoregions/w... Manuka State Park, island of Hawaii

6. Ch 3.1 Communities Eventually community will reach an equilibrium –Climax Community: stable, with little or no change in species. –Does not mean all change stops, it’s just balanced otit.botany.wisc.edu/images/veg/Southern_Mes

7. Ch 3.1 Communities Secondary Succession – –Existing community is severely disrupted Forest fire Still contains soil –Takes less time www.uwgb.edu/.../arbo20020809_19succession_p.jpg farm1.static.flickr.com/76/210237746_726bf0da...

8. Ch 3.1 Communities www.kscience.co.uk/.../images/succession.jpg www.newscientist.com/.../dn10592-2_356.jpg A= 3 yrs B = 15 yrs C= 80 yrs