Exam #2 F 6/27 in class (bring cheat sheet)

Ecology: We are all connected and interdependent

CB Carrying Capacity exponential growth stationary phase Carrying capacity can be limited by competition

CB 53.2 Competition limits where species can live

CB 53.2 niche- the specific environment where a species lives

CB 53.3 Tree species existing in different niches

39% 23% 36% 2% Why are species going extinct?

Grizzly Bears

Historical Grizzly Bear range Current Grizzly Bear range

CB Yellowstone Grizzly Bear population increases

63 mi 54 mi 466 mi of roads 950 mi of backcountry trails 97 trailheads 287 backcountry campsites Yellowstone NP

CB Artificial corridors allow animals to cross fragmented areas

CB Where do grizzly bears fit? Are they important? How much of our resources should we share with grizzly bears?

CB National park Buffer zone In Costa Rica they have a two tiered park system: National Parks- very restricted human activities Buffer zones- some restrictions on human activities

CB National park Buffer zone Developed vs Developing nations: Should/would the US designate such large areas as parks?

63 mi 54 mi 466 mi of roads 950 mi of backcountry trails 97 trailheads 287 backcountry campsites Yellowstone NP

Wolves in Yellowstone National Park

The last wolves in Yellowstone (1920’s)

Wolves commonly live in packs

SocialvsSolo Packs can kill larger prey

Packs give the ability to obtain more food, but also mean sharing food, reduced chance of reproduction, and increased chance of diseases.

Wolves are very territorial and will kill intruders

Wolves were re-introduced to Yellowstone in 1995

Wolf relocation

“hard” release: directly to new location In Yellowstone used“soft” release: Kept in 1 acre pens to acclimate to new environment

Wolves were re-introduced to Yellowstone in 1995

Yellowstone area wolf packs 2004

Wolf deaths deaths= 33%

Currently about 300 wolves sheep and 66 cattle = $32, sheep, 57 cattle, and 6 other animals = $70,000 The cost of wolves in Yellowstone NP:

Estimate millions of dollars in increased visitors

Predator-predator interactions

CB Yellowstone Grizzly Bear population increases

Wolves are decreasing the elk population

Benefits of decreasing herbivore populations

Increased Riparian Habitat

Fig 2 Increased Riparian Habitat

Fig 2 Increased Riparian Habitat

Fig 3 Increased Riparian Habitat

Fig 5 Are wolves responsible? year

Fig 6 Protection vs herbivory gully depth vs browsing

Fig 6 The greatest difference has been in the deepest gullies, which are at the greatest risk to errosion.

The reintroduction of wolves to Yellowstone NP has had numerous positive benefits.

The reintroduction of wolves to Yellowstone NP has had numerous positive benefits: More food available for other carnivores

Fig 3 The reintroduction of wolves to Yellowstone NP has had numerous positive benefits: Increased Riparian Habitat

Bears (1993) Ian Stirling et al., Weldon Owen Pty Ltd pg 231 Animal behavior is unpredictable and inexplicable

CB Not all habitats are equal How do stable ecosystems develop?

Primary Succession- the first organisms to colonize bare rock Secondary Succession- recovery from a disturbance