No part of the world is unaffected by our presence, and we have the ability to modify environments on a massive scale. Our effects, which began in small ways millions of years ago and grew in proportion to the growth of the human population, can be considered positive or negative, depending on perspective. .
Most basic principles of biology can be illustrated in the context of these elements, but those that are based on relationships among two or more species do not always clearly fall within features of the environment such as climate and soils or adaptations of individual species. These principles include the broad category of trophic relationships (food webs, productivity, decomposition, nutrient cycles) and interactions such as predator-prey relationships, competition, and symbiosis. .
CHARACTERISTICS OF BIOCLIMATIC ZONES .
WORLD .
CLIMATE. There is a temperature gradient from the equator to the poles because of the earth's orientation toward sun. The rotation of the earth and the inertia of the air above it causes westerly winds at the equator. The Coriolis force deflects winds to the right in the northern hemisphere and to the left in the southern hemisphere, causing wind gyres. Equatorial air rises and, deflected, falls back to the surface in temperate latitudes, where it then flows toward the east. Wind patterns produce major ocean currents revolving counter-clockwise in the northern hemisphere and clockwise in the southern hemisphere in each ocean basin. Current gyres carry cold water toward the equator on east sides of the oceans, warm water to higher latitudes on the west sides. The temperature of water bodies affects nearby land masses greatly, although there is less effect with distance from water. Land masses and underwater topography deflect currents into complex patterns near the continents. These in turn cause upwellings, which affect productivity and thus diversity and abundance of marine organisms, including those such as birds and pinnipeds that are based on land.