man versus nature

I have often wondered whether our "management" of nature is a good or bad thing. It seems as though there are perpetual arguments for either side of this debate, but I believe that the guiding factor would probably be the "use" or intention not to "use" the land.

Managing park lands requires a much different approach than managing natural lands. Parklands are to remain green and "pretty" while natural lands are to remain... well... natural. Does "natural" mean managing for disease and the health of the landscape, or are we to allow mother nature to decide whether or not to take care of herself? One could argue that much of the disease and infestation we are seeing in our forestlands are the result of man introducing non-native species into the landscape, and therefore we are taxed with the responsibility to band-aid the problem the best we are able. But one could also argue that this is nature's way of ridding itself of the weakest link, even if man introduced it to the area earlier than nature had intended.

Are we acting as good stewards of the land when we try to promote long life in natural lands, or are we robbing the understory and its inhabitants of much needed decay/nutrition, and thereby interrupting the "circle of life"?

What a quandary...