Every restoration follows a value judgment on the present and the past. Which does one prefer? To restore a previous ecology, for example, someone has to alter the present ecology. The work of Gregory P. Dietl and Karl Flessa on former clam reefs of the lower Colorado River frames the problem at hand.* Before large dams and their reservoirs changed the river, the water regularly reached the Gulf of California and provided a home for huge numbers of huge clams (up to 30 cm). Siphoning of the water for use by various states lowered the river’s discharge and isolated clams once abundant in the northern part of the Gulf. Dietl and Flessa, in using the high-and-dry clam shells to reconstruct the past ecology, initiated a field of study now called conservation paleobiology, a science devoted to understanding past ecologies through their fossil remains and possibly using those remnants of the past to reconstruct it as a present-day ecological system.
Restoring the past always presents a dilemma. Obviously, the “need” for restoration arises from the present’s supplanting the past. So, which ecology or neighborhood should be preserved? The one that is occupied by its own set of organisms dwelling on the current landscape with its processes or the one occupied by a different set of organisms in a different landscape with its endemic processes? Any restoration also involves a cheat. Does anyone believe we can truly restore the past with exactitude?
Longwall mining can change the surface through subsidence. As the mining machines excavate the coal deep underground, they leave no support for the surface that can sink soon after the mining occurs. Subsidence changes the way streams flow on the surface. Sometimes freely flowing streams are interrupted by “bumps” and depressions that cause the water to pond. Organisms that were happy in free-flowing water are then replaced by opportunistic organisms that like slow-flowing water in pools. So, here’s your problem. Do you break through the dam caused by the subsidence and buckling of the surface caused by the underground mining in order to restore the former ecology? If you do break through the dam, do you do so without concern for the replacement ecology that formed in the pond? That is, do you value the organisms of the past more than you value the organisms of the present?
And in your current life, do you seek to restore without regard to the circumstances of the present? The life of the past might have been worth preserving before it changed, but is the life of the present not worth preserving? And if you believe the life of the present is not worth preserving, then on what basis do you evaluate and judge and to what extent do you believe you can restore with exactitude?
* Dietl, Gregory P. and Karl W. Flessa, Conservation paleobiology: putting the dead to work
DOI: http://dx.doi.org/10.1016/j.tree.2010.09.010, Trends in Ecology & Evolution, Volume 26, Issue 1, Pp. 30-37, Published online October 29, 2010.
Restoring the past always presents a dilemma. Obviously, the “need” for restoration arises from the present’s supplanting the past. So, which ecology or neighborhood should be preserved? The one that is occupied by its own set of organisms dwelling on the current landscape with its processes or the one occupied by a different set of organisms in a different landscape with its endemic processes? Any restoration also involves a cheat. Does anyone believe we can truly restore the past with exactitude?
Longwall mining can change the surface through subsidence. As the mining machines excavate the coal deep underground, they leave no support for the surface that can sink soon after the mining occurs. Subsidence changes the way streams flow on the surface. Sometimes freely flowing streams are interrupted by “bumps” and depressions that cause the water to pond. Organisms that were happy in free-flowing water are then replaced by opportunistic organisms that like slow-flowing water in pools. So, here’s your problem. Do you break through the dam caused by the subsidence and buckling of the surface caused by the underground mining in order to restore the former ecology? If you do break through the dam, do you do so without concern for the replacement ecology that formed in the pond? That is, do you value the organisms of the past more than you value the organisms of the present?
And in your current life, do you seek to restore without regard to the circumstances of the present? The life of the past might have been worth preserving before it changed, but is the life of the present not worth preserving? And if you believe the life of the present is not worth preserving, then on what basis do you evaluate and judge and to what extent do you believe you can restore with exactitude?
* Dietl, Gregory P. and Karl W. Flessa, Conservation paleobiology: putting the dead to work
DOI: http://dx.doi.org/10.1016/j.tree.2010.09.010, Trends in Ecology & Evolution, Volume 26, Issue 1, Pp. 30-37, Published online October 29, 2010.
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