110
D.T. Solbrig
manifold economic activities are the manifestation of the drive we share with every
other species to obtain as many resources as possible to fulfill our need to survive,
grow and reproduce.
The transformations of our surroundings have a direct impact on the functioning of ecosystems. Not only are native species populations reduced or eliminated,
the abiotic components of the ecosystem are also profoundly affected and the flows
of energy and materials modified. Drainage patterns are changed, resulting in new
and sometimes very intense erosive processes, in silting of rivers and wetlands, in
loss of soil nutrients and organic matter, and in the nutrient and water retention
capacity of the soil. The loss of vegetation accelerates erosion. From an ecosystem
perspective, the loss of species is only one aspect of the transformation of landscapes, and possibly not the most worrisome.
The transformations of natural landscapes is not the result of a grand conspiracy
by particular individuals, or groups of individuals, industry, governments, or other
institutions in the society. Neither the rich, nor the poor, the inhabitants of developed countries, or those living in developing nations, arc especially interested in
destroying or modifying the function of natural ecosystems. Much to the contrary,
most everybody admires natural environments, and given a chance tries to recreate
them in their homes and gardens. Y ~t we all are modifying the natural environment day by day, month by month, usually without realizing it. Each day, hundreds, thousands, if not millions of decisions are made by individuals, governments, businesses, and industries that affect our surroundings. Some decisions have
only a small impact, and others a very great one. Most of these decisions are made
by people to increase their wealth and improve their economic well being. A house
here, a road there, a factory that will give employment, a business that cuts down
only a part of a forest, an excess of fertilizer to insure a good crop, a little bit of
some chemical poison dumped into a river, or into the air, a bigger car, an extra
appliance, and so on, lead to the transformation and eventual degradation of the
natural environment. While each decision will usually have only a small local effect, collectively thcy will have a tremendous effect, and because of the nature of the
process nobody feels responsible for the global effect.
Because the process of habitat modification is normally highly dispersed, to
understand it, the individual decisions and the motivations behind them need to be
studied in detail. Aggregate data on how many hectares of land are lost to development, or guesses regarding the number of species lost, or calculations of how many
tons of soil are lost to erosion each year, although useful as an indication of the
overall human impact, cannot determine the causes of the process. Only by studying human decisions at the micro level can we ever understand the dynamics of the
process of transformation and develop realistic policies to stop it. Some industry
organizations are trying to do this (Hawken 1993) but ecologists have been very
reluctant to study systems in flux due to human activity. Trained to control our
variables, we prefcr to study systems where the uncontrollable human impact is
minimal, and our first inclination is to put a fence around our study sites to exclude
disturbance by people. However, in order to understand human impact we must
consider people as part of the system and include them in our studies just like any
D.T. Solbrig
manifold economic activities are the manifestation of the drive we share with every
other species to obtain as many resources as possible to fulfill our need to survive,
grow and reproduce.
The transformations of our surroundings have a direct impact on the functioning of ecosystems. Not only are native species populations reduced or eliminated,
the abiotic components of the ecosystem are also profoundly affected and the flows
of energy and materials modified. Drainage patterns are changed, resulting in new
and sometimes very intense erosive processes, in silting of rivers and wetlands, in
loss of soil nutrients and organic matter, and in the nutrient and water retention
capacity of the soil. The loss of vegetation accelerates erosion. From an ecosystem
perspective, the loss of species is only one aspect of the transformation of landscapes, and possibly not the most worrisome.
The transformations of natural landscapes is not the result of a grand conspiracy
by particular individuals, or groups of individuals, industry, governments, or other
institutions in the society. Neither the rich, nor the poor, the inhabitants of developed countries, or those living in developing nations, arc especially interested in
destroying or modifying the function of natural ecosystems. Much to the contrary,
most everybody admires natural environments, and given a chance tries to recreate
them in their homes and gardens. Y ~t we all are modifying the natural environment day by day, month by month, usually without realizing it. Each day, hundreds, thousands, if not millions of decisions are made by individuals, governments, businesses, and industries that affect our surroundings. Some decisions have
only a small impact, and others a very great one. Most of these decisions are made
by people to increase their wealth and improve their economic well being. A house
here, a road there, a factory that will give employment, a business that cuts down
only a part of a forest, an excess of fertilizer to insure a good crop, a little bit of
some chemical poison dumped into a river, or into the air, a bigger car, an extra
appliance, and so on, lead to the transformation and eventual degradation of the
natural environment. While each decision will usually have only a small local effect, collectively thcy will have a tremendous effect, and because of the nature of the
process nobody feels responsible for the global effect.
Because the process of habitat modification is normally highly dispersed, to
understand it, the individual decisions and the motivations behind them need to be
studied in detail. Aggregate data on how many hectares of land are lost to development, or guesses regarding the number of species lost, or calculations of how many
tons of soil are lost to erosion each year, although useful as an indication of the
overall human impact, cannot determine the causes of the process. Only by studying human decisions at the micro level can we ever understand the dynamics of the
process of transformation and develop realistic policies to stop it. Some industry
organizations are trying to do this (Hawken 1993) but ecologists have been very
reluctant to study systems in flux due to human activity. Trained to control our
variables, we prefcr to study systems where the uncontrollable human impact is
minimal, and our first inclination is to put a fence around our study sites to exclude
disturbance by people. However, in order to understand human impact we must
consider people as part of the system and include them in our studies just like any