ECON 1 Lecture Notes - Lecture 4: Weak Interaction, Phylogenetic Diversity, Null Hypothesis
Document Summary
Interaction diversity competition, parasitism, predation, facilitation with other species. Types of diversity: alpha diversity within a site, normal diversity , beta diversity differences between two sites, similarity indices (sorenson, bray-curtis) at this level, gamma diversity overall diversity of region or ecosystem ( species pool ) Loss of diversity across trophic levels influences ecosystem functions more strongly than within: food web interactions are mediators of ecosystem functioning, loss of higher consumers can cascade to plants, alter vegetation structure, fire frequency, disease epidemics. Ecosystem services: suite of benefits that ecosystems provide to humanity. Food web stability: complex food webs are more stable. In 1950, it was shown: monocultures were more vulnerable compared to stable diverse tropical rainforests or coral reefs, more frequent invasions to simple islands compared with complex mainland. Mountain pine beetle: outbreak in british columbia was largest ever seen, map shows infestation .
