Eco Eco Ecology

In order to ascertain the best or "best" means of approaching environmental problems, some scientific background is helpful. It is useful when confronted by conflicting claims on an issue by various groups, all of whom may have some amount of scientific justification to support what they state. It is also useful when networking with people trained in ecology and environmental sciences to be able to share a common language, if only because it helps foster mutual respect. (The scientist in me cringes everytime I hear, "Don't eat that! There are chemicals in that!" and I'm not as likely to listen to the rest of what the person has to say on the issue.) Being able to understand the terminology used in field research and in Environmental Impact Statements is useful for anyone concerned with specific environmental issues.

Back in 1866, when the word "ecology" was first being coined by the German naturalist Ernst Haeckel, students of this fledgling science wanted a systematic way to describe the interrelationships between organisms and their environment. Ecology comes from oikos (household) and logos (study of). It was not until the late sixties that ecology became strongly associated with the various environmental movements, although the science had played a role in the establishment of the National Park System, and early naturalist/ecologists such as Aldo Leopold called for a land ethic.

Onwards into some definitions:

Population ecology is the study of a population of a single species of plant or animal within an area or range. Scientists who study this concentrate on patterns of fluctuations in given populations, and attempt to discover reasons as well as project trends. Often one population will oscillate in relation to another one (typical of a predator/prey relationship).

The carrying capacity is the maximum population size that the environment can support without deterioration.

Community ecology is the study of all organisms in a given area or region. Interactions between these species are of prime importance. Communities evolve over time -- a cleared field will, given enough time, go through various stages of community development in a process called succession until it reaches what is termed a climax community. An example of a climax community is the oak-maple community of much of the northeastern and midwest U.S. Indicator species can determine the stage a particular community is in, as well as its relative health.

An ecosystem consists of both the living (biotic) and physical (climatic, geologic) environment of an area. A simple ecosystem might be a desert; one of the most complex would be a rainforest. A terrarium is an example of a very small and artificial ecosystem. That cleared field mentioned above is also an ecosystem, when one takes into account the physical environment. Ecosystems are often considered to be the fundamental units of nature, although it is known that neighboring ecosystems can and do influence each other.

A biome is a much larger region of a dominant type of vegetation. The prinicple world biomes are tundra, grassland, desert, coniferous forest, temperate deciduous forest, chapparal, tropical savanna, tropical deciduous forest, and rainforest.

Looking at the smaller end of the scale, an organism's niche in the community can be analogous to its occupation -- that is, its unique way of life -- where it lives and what it does.

The biogeochemical cycles which affect all of the above are also studied in environmental sciences. As a very simplified example, producers (photosynthesizers) provide oxygen and are eaten by the consumers (animals, parasitic plants), which are in turn broken down by the decomposers (mainly microorganisms), and then returned to the producers. Similar paths describe the carbon, nitrogen, oxygen, and other cycles. Nutrients, in a balanced system, will fluctuate to some degree. To some extent, there is built-in flexibility -- "all environmental systems operate on some principle of dynamic balance" (Darnell).

Change is built right into the system. Even climax communities change given enough time. Climate fluctuations are an obvious factor. Less obvious is the soil -- after generations and generations of soil buildup and decay, nutrients and pH essential for the prime trees of the climax community may vary enough that other plants supplant the original.

Eutrophication is a process which occurs eventually in most freshwater bodies of non-moving water; the smaller, the sooner. Nutrient buildup results in a burst of algae population, resulting in less available oxygen. Fish die off, and that familiar scummy, smelly appearance results. The next stage may eventually be a bog. In time, the pond or small lake fills in. This process is encouraged by fertilizer run-off and the use of phosphate detergents in areas where detergents may leach into such waters.

Environmental predictibility is based on careful analysis of the factors discussed above. Note that events that correlate need not necessarily indicate causation in either direction. Environmental dynamics cover a multitude of factors.

Human management of the land requires a lot of fine-tuning and scientific understanding, as well as the possibility that a given choice might be wrong. After the Disney movie Bambi was initially released, there was a public outcry about forest fires in the National Parks, in sympathy for the title character. The government responded by putting out each and every fire they noticed. After a while, there was a lot of dead brush from the course of events, and in the continuing course of events when fires finally struck years down the line, they were impossible to contain until after severe damage had been done. Nowadays, a policy of controlled burns is maintained to minimize the numbers of major forest fires in the National Parks. Indeed, there is a species of pine in the American northwest whose cones are triggered to release seeds by the stimulus of fire. The indication here is that in certain ecosystems, fire is an expected occurrence.

Future articles will take a tighter focus in looking at environmental issues. At Yule, we shall look at early human societies and ask if it is possible to blame technology and/or a monotheistic world view for environmental ills. At Imbolc, in preparation for Spring and the planting season, we shall discuss organic and environmental home gardening -- what you can do, and why. At other points, we will discuss specific ecosystems in some depth.

Darnell, R.M. 1973. Ecology and Man, Wm. C. Brown Company.

Emmel, T.C. 1973. An Introduction to Ecology and Population Biology, W.W. Norton & Co.

Leopold, A. 1949. A Sand County Almanac, Sierra Club.

(Document Copyright as Freeware © 1994 by Jehana Silverwing. Permission is hereby granted to reprint this document in its entirity. My name and this notice must remain intact.)