BIOL 3170 Lecture Notes - Lecture 1: Habitat Destruction, Defragmentation, Introduced Species
Document Summary
Currently experiencing the 6th mass extinction: extinction rates are about 100-1000x higher than those prior to 20th century back to last mass extinction. Threats to biodiversity (reasons for extinctions: overexploitation, for food, ornamental value, pest control, habitat destruction, as human popln increases, mining, forestry, urbanization increases. Habitat defragmentation: the division of a large habitat into smaller, isolated pieces, oftentimes, larger and territorial animals, such as carnivores cannot survive in such fragments. Increases extinction risks for many animals previously inhabiting the area. In ecology, ecologists work at 4 main levels: organismal, population, all individuals of one species in a defined area, community, all populations in a defined area, ecosystem, community plus all abiotic (non-living) factors in an area. Community ecology: examines the interactions between populations of different species, as well as how they respond to disturbances such as fires or floods, flowers (thistle) and pollinators (bumblebee and clear-wing moth).
