Ecological Monitoring

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Ecological monitoring

Governments everywhere are increasingly recognizing the fact that human activities are causing serious environmental and ecological damage. To effectively deal with this environmental crisis, it is important to understand its dimensions and dynamics. What, specifically, are the damages, how are they changing over time , and what are the best means of prevention or mitigation? To develop answers to these important questions, longer-term programs of monitoring and research must be designed and implemented. These programs must be capable of detecting environmental and ecological change over large areas, and of developing an understanding of the causes and consequences of those changes.

Humans and their societies have always been sustained by environmental resources. For almost all of human history the most important resources have been potentially renewable, ecological resources. Especially important have been fish and terrestrial animals that could be hunted, edible plants that could be gathered, and the productivity of managed, agricultural ecosystems. More recently, humans have increasingly relied on the use of nonrenewable mineral resources that are mined from the environment, especially fossil fuels and metals.

However, the ability of ecosystems to sustain humans is becoming increasingly degraded. This is largely because of the negative consequences of two, interacting factors: (1) the extraordinary increase in size of the human population, which numbered about 6.0 billion in 1999, and (2) the equally incredible increase in the quantities of resources used by individual humans, especially people living in developed countries with an advanced economy, such as those of North America and Western Europe .

Environmental and ecological degradations are important for two reasons: (1) they represent decreases in the ability of Earth's ecosystems to sustain humans and their activities, and (2) they represent catastrophic damage to other species and to natural ecosystems, which have their own intrinsic value, regardless of their importance to humans. The role of programs of environmental and ecological monitoring is to detect those degradations, to understand their causes and consequences, and to find ways to effectively deal with the problems.

Monitoring, research and indicators

In the sense used here, environmental monitoring is an activity that involves repeated measurements of inorganic, ecological, social, and/or economic variables. This is done with a view to detecting important changes over time, and to predicting future change. Within this larger context, ecological monitoring deals with changes in the structure and functioning of ecosystems.

Monitoring investigates scientific questions that are rather uncomplicated, involving simple changes over time. However, the success of monitoring depends on: (1) the astute choice of a few, appropriate indicators to measure over time, from a diverse array of potential indicators, and (2) successful data collection, which can be expensive and difficult, and requires longer-term commitments because important changes may not detectable by short-term studies.

It is important to understand that monitoring programs must be integrated with research, which examines relatively complex questions about the causes and consequences of important environmental and ecological changes that may be detected during monitoring. The ultimate goals of an integrated program of ecological monitoring and research are to: (1) detect or forecast changes, and (2) determine the causes and implications of those changes.

Monitoring involves the repeated measurement of indicators, which are relatively simple measurements related to more complex aspects of environmental quality. Changes in indicators are determined through comparison with their historical values, or with a reference or control situation. Often, monitoring may detect changes in indicators, but the causes of those changes may not be understood because the base of environmental and ecological knowledge is incomplete. To discover the causes of those changes, research has to be undertaken.

For example, monitoring of forests might detect a widespread decline of some species of tree , or of an entire forest community. In many cases the causes of obvious forest declines are not known, but they are suspected to be somehow related to environmental stressors, such as air pollution , insect damage, climate change, or forestry . These possibilities must be investigated by carefully designed research programs. The ecological damages associated with forest declines are very complex, and are related, for example, to changes in: productivity, amounts of living and dead biomass , age-class structure of trees and other species, nutrient cycling, soil erosion , and biodiversity values. However, in an ecological monitoring program designed to study forest health, only a few well-chosen indicators would be measured. A sensible indicator of changes in the forest as an economic resource might be the productivity of trees, while a species of mammal or bird with specific habitat needs could be used as an indicator of the ecological integrity of mature or older-growth forests.

Indicators can be classified according to a simple model of stressor-exposure-response:

Stressors are the causes of environmental and ecological changes, and are associated with physical, chemical, and biological threats to environmental quality. Stressors and their indicators are often related to human activities, for example, emissions of sulfur dioxide and other air pollutants, concentrations of secondary pollutants such as ozone , the use of pesticides and other toxic substances, or occurrences of disturbances associated with construction, forestry, or agriculture. Natural stressors include wildfires, hurricanes, volcanic eruptions, and climate change.
Exposure indicators are relevant to changes in the intensity of stressors, or to doses accumulated over time. Exposure indicators might only measure the presence of a stressor, or they might be quantitative and reflect the actual intensity or extent of stressors. For example, appropriate exposure indicators of ozone in air might be the concentration of that toxic gas, while disturbance could be indicated by the annual extent of habitat change caused by forest fires, agriculture, clear-cutting, or urbanization.
Response indicators reflect ecological changes that are caused by exposure to stressors. Response indicators can include changes in the health of organisms, populations, communities, or ecoscapes (landscapes and seascapes).

Indicators can also take the form of composite indices, which integrate complex information. Such indices are often used in finance and economics, for example, stock-market indices such as the Dow-Jones, and consumer price indices. For reporting to the public, it is desirable to have composite indices of environmental quality, because complex changes would be presented in a simple manner. However, the design of composite indices of environmental quality or ecological integrity are controversial, because of difficulties in selecting component variables and weighing their relative importance. This is different from composite economic indicators, in which all variables are measured in a common currency, such as dollars.

Monitoring addresses important issues

Environmental monitoring programs commonly address issues related to changes in: (1) environmental stressors, for example, the chemical quality of water , air, and soil, and activities related to agriculture, forestry, and construction; (2) the abundance and productivity of economically important, ecological resources such as agricultural products, forests, and hunted fish, mammals , and birds ; and (3) ecological values that are not economic resources but are nevertheless important, such as rare and endangered species and natural communities.

Monitoring programs must be capable of detecting changes in all of the above values, and of predicting future change. In North America, this function is carried out fairly well for categories (1) and (2), because these deal with economically important activities or resources. However, there are some important deficiencies in the monitoring of noneconomic ecological values. As a result, significant environmental issues involving ecological change cannot be effectively addressed by society, because there is insufficient monitoring, research, and understanding. A few examples are:

Is a widespread decline of populations of migratory songbirds occurring in North America? If so, is this damage being caused by stressors occurring in their wintering habitat in Central and South America ? Or are changes in the breeding habitat in North America important? Or both? What are the causes of these changes, and how can society manage the stressors that are responsible?
What is the scope of the global biodiversity crisis that is now occurring? Which species are affected, where, and why? How are these species important to the integrity of the biosphere , and to the welfare of humans? Most of the extinctions are occurring because of losses of tropical forest, but how are people of richer countries connected to the biodiversity-depleting stressors in poorer countries?
What are the biological and ecological risks of increased exposures to ultraviolet radiation , possibly caused by the depletion of stratospheric ozone resulting from emissions of chlorofluorocarbons by humans?
What constitutes an acceptable exposure to potentially toxic chemicals? Some toxins, such as metals, occur naturally in the environment. Are there thresholds of exposure beyond which human emissions should not increase the concentrations of these chemicals? Is any increase acceptable for non-natural toxins, such as synthetic pesticides, TCDD, PCBs, and radionuclides?

These are just a small sample of the important ecological problems that have to be addressed by ecological monitoring, research, and understanding. To provide the information and knowledge needed to deal with environmental problems, many countries are now designing programs for longer-term monitoring and research in ecology and environmental science.

In the United States, for example, the Environmental Monitoring and Assessment Program (EMAP) of the Environmental Protection Agency is intended to provide information on ecological changes across large areas, by monitoring indicators at a large number of sites spread across the entire country. Another program has been established by the National Science Foundation and involves a network of Long-Term Ecological Research (LTER) sites (21 in 1999), although these are mostly for fundamental ecological research and are not necessarily relevant to environmental problems. These are important programs in ecological monitoring and research, but they are still in their infancy and it is too soon to determine how well they will contribute to resolution of the environmental crisis.

State-of-the-environment reporting and social action

The information from programs of environmental monitoring and research must be reported to government administrators, politicians, corporations, and individuals. This information can influence the attitudes of these groups, and thereby affect environmental quality. Decision makers in government and industry need to understand the causes and consequences of environmental damage, and the costs and benefits of alternative ways of dealing with those changes. Their decisions are based on the balance of the perceived costs associated with the environmental damage, and the shorter-term, usually economic benefits of the activity that is causing the degradation.

Information from environmental monitoring and research is interpreted and reported to the public by the media, educational institutions, state-of-the-environment reporting by governments, and by non-governmental organizations. All of these sources of information help to achieve environmental literacy, which eventually influences public attitudes. Informed opinions about the environment will then influence individual choices of lifestyle, which has important, mostly indirect effects on environmental quality. Public opinion also influences politicians and government administrators to more effectively manage and protect the environment and ecosystems.