BIOL 4150 Lecture 12: Lecture 12 & 13

• School: University of Guelph
• Department: Biology
• Course: BIOL 4150
• Professor: Andrew Mac Dougall

Document Summary

Humans may be fertilizing the monoculture unknowingly (nitrogen enrichment of soil by pollution) Regulatory mechanisms change to allow monocultures to grow. Predictions: eventually monocultures become targets from consumers (insects, herbivores, monocultures are doomed to crash at some point. Not able to eat large prey (specialized beak) There may be predation at higher heights in. The niche of the insect drives the niche of trees the bird. The portfolio effect: compares biodiversity to stock holdings, where diversification minimizes the volatility of the investment, or in this case, the risk in stability of ecosystem services. Invasive species: introduced to a location where it did not previously occur. 1: demographically positive (lambda >1) , spreads widely throughout location. 4: severe, often irreversible impacts on agriculture, recreation, and natural resources, 2nd major threat to biodiversity worldwide; affects 40% of endangered species in north. Economic costs = billions of dollars each .