1) Ecology is the scientific study of the distribution and abundance of organisms, the interaction among organisms, and the interactions between organisms and their abiotic environment. Ecologists try to understand the inner workings of natural ecosystems and the species they contain.
2) Ecosystems have no particular size. An ecosystem can be as large as a desert or a lake or as small as a tree or a puddle. If you have a terrarium, that is an artificial ecosystem. The water, water temperature, plants, animals, air, light and soil all work together.
3) The biotic factors of an ecosystem include all the populations in a habitat, such as all the species of plants, animals, and fungi, as well as all the micro-organisms. Also recall that the nonliving factors are called abiotic factors. Abiotic factors include temperature, water, soil, and air.
4) For aquatic ecosystems, these factors include light levels, water flow rate, temperature, dissolved oxygen, acidity (pH), salinity and depth.
The grasses, which acted as a windbreak and whose roots anchored the soil in place, were overgrazed and/or removed to allow for farming. Once a few years of severe drought affected the area, any wind storm was able to blow the topsoil away, rendering the farm land of the Great Plains virtually unusable in many areas. Ground cover is an essential part of sustainable agriculture.
