48.  What is a practice in which farmers often follow loggers access roads, cut down the trees, burn the area, and plant crops immediately?

35.  What environment is characterized by high nutrient inputs and by relatively great fluctuations in salinity and temperature?

22.  A linear depiction of energy flow in an ecosystem is a?

26.  Transpiration is most closely associated with:

50.  Stratospheric ozone is important because it:

37.  The most productive region of a lake is the ____ zone.

29.  The primary reason that Earth experiences seasons is because of the:

13.  Habitat is best described as:  

44.  Today, the major danger to species is:

41.  Building roads, parking lots, building and bridges all contribute to: