Week2 - Patterns of Biodiversity Biogeography's central...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Patterns of Biodiversity • Biogeography’s central tenet is that each species has a unique geographic range = basic unit of biogeography Range maps • Outline – depicts the range as an irregular area within a boundary • Dot – points plotted on map where spp has been recorded • Contour – indicate variation in density in the range
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Populations • factors that affect the size, density, and distribution of populations – environment – survival – reproduction – dispersal Thomas Malthus (1798) - Essay on the Principle of Population r = b + i - d - e r = per capita rate of growth b = birth rate d = death rate i = immigration e = emigration dN/dt = rN = exponential growth
Background image of page 2
Multidimensional niche concept (Evelyn Hutchinson 1957) • Geographic range is a reflection of the niche – Joseph Connell’s study of barnacles (1961) - pioneered use of field experiments in ecology • Three niche variables: desiccation, competition, predation • Location of range boundaries thus depend on both abiotic and biotic factors • Source and sink habitats • Metapopulation Distribution and Abundance • Species tend to be most abundant where niche is favorable, and less abundant in less favorable habitats • Range boundaries – affected by physical factors, disturbance, and interactions with other organisms
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
• Justus von Liebig (1840): Liebeg’s law of the minimum - biological processes are limited by that single factor that is in shortest supply relative to demand, or for which the organism has the least tolerance – may be too simplistic in light of multidimensional niche concept • animals can generally disperse to better microclimates, whereas plants and sessile animals are more limited Disturbance • Fires, hurricanes, volcanic eruptions, earthquakes, tornados, avalanche, landslide, tsunami • Ecological succession: primary vs secondary • Fire ecology: chaparral, prairie, forests, hurricane regimes: islands, offshore coral reefs; intertidal habitats • Periodic disturbance may limit invasion of habitat by certain species
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/17/2008 for the course EEOB 700 taught by Professor Wolfe during the Winter '05 term at Ohio State.

Page1 / 24

Week2 - Patterns of Biodiversity Biogeography's central...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online