BIOC58H3 Final: FINAL NOTES BIOC58_LEC 6 7 8.docx
8 Dec 2013
School
Department
Course
Professor
Document Summary
Lecture 6 : biological impacts on climate change. Species distribution: factors to consider: niche, tolerances, geographic ranges, ecotypes, community organization, extinction processes, species ranges: from refugia to habitat expansion. Hypothetical diagram of the niche space of two species, s1 and s2. Only two environmental variables are used for illustration, but thisapproach could be extended to three variables to define volume, or to four or more variables to define a hyper volume. This has been called the fundamental niche of a species. The niche space of species may overlap to a greater or lesser extent. Hypothetical comparison of the tolerance of an organism and the temperature or moisture ranges of the microclimate where it lives. The tolerance zone is measured for the stage of the life cycle that is most sensitive to temperature or moisture and is subdivided into two zones, the optimal zone (dark blue) and the marginal zone (light blue).
