Environmental effects on organisms

1. Environmental effects on organisms Ch 6.2 and 6.3

2. Distribution - where a particular species is found • Abundance - number of the species in that locality • Altitudinal zonation - zones of climate, vegetation, and crops that change with height above sea level. • Latitudinal zonation - predictable changes in community composition as one moves away from the equator

3. Ecological Succession - The gradual and orderly process of change in an ecosystem brought about by the progressive replacement of one community by another until a stable climax is established • Primary Succession - The series of changes that occur in an area where no ecosystem previously existed • Pioneer Species - The first species to live in an area of primary succession • Micro-environments - climate within a small area that differs significantly from the climate of the surrounding area eg a cave

4. Dominant species - A species with substantially higher abundance or biomass than other species in a community. Dominant species exert a powerful control over the occurrence and distribution of other species. • Climax Community - A stable, mature community that undergoes little or no change in species over time. • Secondary Succession - The series of changes that occur after a disturbance of an existing ecosystem

5. Invasive Species - Species that enter new ecosystems and multiply, harming native species and their habitats • Disclimax community - results from degradation of a community due to activities of organisms the eventually leads to desertification • Desertification - Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting.