ENVS 110 Lecture Notes - Lecture 5: Control Character, Sea Urchin, Keystone Species

• School: SJSU
• Department: Environmental Studies, Department of
• Course: ENVS 110
• Professor: Professor

Document Summary

Domains of life: we can trace similarities and make a family tree of all organisms, can change with new knowledge. Population ecology: study of populations and why their numbers change over time. Indirect indicators: rodent burrows, bird nests, dispersal, age structure, growth rate. One species will always be better and win. 1960 robert paine (american ecologist) said lets test this: removal of sea star (pistaster ochraeceus, mussels increased overall diversity decreased. Sea otters: at one time, they ranged in a continuous arc from japan to baja california. In us, wolves were hunted to extinction, people feared and gov. paid citizens for removal: 1996, wolves were reintroduced to yellowstone national park, caught in canada, flown in crated and then released. Mountain lions, wolves, elk, beavers, bison, song birds: the aspen trees stopped regenerating in the 1930"s and haven"t regenerated since that time. Yellowstone"s last wolf dead: what was the possible cause of the aspen trees" disappearance from yellowstone.