Biology 2483A Lecture Notes - Aspen, Acclimatization, Northern Range
23 Nov 2012
School
Department
Course
Professor
Document Summary
Two options for coping with environmental change (such as seasonal temperatures) are tolerance and avoidance. The potential geographic ranges of species are determined by the physical and biological environments. The physical environment influences an organism"s ecological success (its survival and reproduction) in two ways: 1. It affects the availability of energy and resources, impacting growth and reproduction. Extreme conditions can exceed tolerance limits and impact survival. Energy supply can influence an organism"s ability to tolerate environmental extremes. The actual geographic distribution of a species is also related to other factors, such as disturbance and competition. The abundance of organisms is at a maximum at an optimal value across an environmental gradient (temperature, precipitation, salinity). So the abundance of organisms would be highest when temperature is at some optimal value (not too high, not too low). The abundance decreases at extreme values that constrain the potential geographic distribution of the organism.
