Ecology and Biodiversity

Ecology and Biodiversity

Describe the Basic Structure and Interactions of a Healthy Ecosystem

All complex systems are, by definition, made up of a number of interacting parts. In general, these components vary in their type, structure, and function within the whole system. Thus a system's behavior cannot be summarized simply by adding up the behavior of the individual parts. Contrast a simple physical system (say, an ideal gas) with a complex biological system (say, an organism) (Holling, 1987). The temperature of the gas is a simple aggregation of the kinetic energy of all the individual molecules in the gas. The temperature, pressure, and volume of the gas are related by simple relationships with little or no uncertainty. An organism, however, is composed of complex cells and organ systems. The state of an organism cannot be surmised simply by adding up the states of the individual components, since these components are themselves complex and have different, non-commensurable functions within the overall system. Indicators that might be useful for understanding heart function - pumping rate and blood pressure, for instance - are meaningless for skin or teeth (Holling, 1986).

Differentiate between Logistic and Exponential Growth

Exponential growth and logistic growth are terms that have been related to population. Exponential growth is that which exists when the growth rate is proportional to existing amounts. In logistic growth also, the growth rate is proportional to the amount but also includes limited resources and competition (Christensen & Pualy, 1992). Certain ideal conditions are required for exponential growth. But logistic growth is not related to any ideal condition. In logistic growth, the rate of growth is faster in the beginning and slows down later as several individuals are seen competing in a limited space. When the population reaches the equilibrium state, the growth rate is zero. If no interruption takes place, then the population will remain constant. A population which has unlimited access to various resources will grow exponentially. Unlike the logistic growth, exponential growth starts slowly and then gets faster as population increases.

Exponential growth happens when there is a continuous birth rate in a period of time and it is not hindered because of the scarcity of food and a lot of diseases. For example, a bacterium divides into two which will result in two bacteria. These 2 further divide which results in 8 and then 16 and 32 and likewise. This process will continue till the resources run out or become scarce (Christensen, 1995).

There are various restrictions, like lack of food, presence of diseases and predators which can restrict the growth of the population. The population reaches an upper limit where the environment can no longer support it. This growth can be called as logistic growth where the population increases exponentially and reaches a point where the resources become insufficient. In exponential growth, there is no upper limit. But in logistic growth, the growth is limited. When comparing the two growths, logistic growth is considered more realistic than exponential growth.

The Importance of Biodiversity

Protecting biodiversity is now very ...