• There are 26 possible points so far
• if your grade as of today is 70%, you have done 18 out of 26
• 13 reading responses have been assigned, there will be 29 more for a total of 84 points (and perhaps a few more)
  
• reading responses and other participation assignments are 20% of your grade
• participation points can also be earned by participating in class discussion (up to 20 points, moderate class participation will earn you 10)
• I also promised other ways to earn up to 30 points and will work on getting some of those up
• absences above 6 result in a deduction from your participation point total
  

• botanists identified plant species and which grew together
• the term ecology was first used in 1869 but did not catch on
  
• ecological succession was studied starting in 1900
• if you start with bare land, one grouping of plants will grow up first
• maybe 10 years later trees will start to grow tall enough to shade the area under them leading to a different grouping of plants
• later on different trees will replace them
• eventually the forest reaches a mature state (as understood at the time) called a climax forest)
  
• the concept of food chains was introduced in 1927
• Ruth Patrick began to measure the health of streams by their diversity of species in the 1940s
• Eugene Odum published the first textbook in ecology in 1953
• increasingly thinking in terms of an interconnected ecosystem rather than individual species
• ecologists in the 1960s emphasized the balance of nature but since then research has shown that ecosystems are always changing
  

• sandy soils that dry very quickly

• how low is the water table?
  
• many different adaptations: leaves that reduce water loss, water storing leaves or roots
• slightly different plants in soils that retain more moisture
• the longleaf forests in richer soils disappeared when trees were cut down and fire suppressed
  

How do you measure diversity?

• the Amazon rain forest has a high number of tree species
• Longleaf pine savannas have a high number of species per square meter (high species packing)
• many plants in the longleaf pine ecosystem are endemic, found only there
• this makes it an important ecosystem to protect if the goal is to avoid extinctions

• the southeast was a refuge for species from farther north and also had more time to evolve
• relative isolation led to adaption to local conditions
• for the role of isolation in evolution see the Galapagos