ch 3.1 communities limiting factors restrict –existence, –numbers, –reproduction, or...
TRANSCRIPT
Ch 3.1 Communities
• Limiting Factors restrict– Existence, – Numbers,– Reproduction, or – Distribution of organisms
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
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...
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
Ch 3.1 Communities
www.cas.vanderbilt.edu/bioimages/ecoregions/w... Manuka State Park, island of Hawaii
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
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...
Ch 3.1 Communities
www.kscience.co.uk/.../images/succession.jpg
www.newscientist.com/.../dn10592-2_356.jpg
A= 3 yrsB = 15 yrsC= 80 yrs