Tom,I've got to be honest here-I've often wondered too about all the ropes and other hiking apparati used to climb the big trees. Surely damage to the unique life communities found high up in the crowns of these trees is ongoing with all the attention..........and in particular, with the new focus on "active" nature recreation, where the point is no longer to passively take in the grandeur, but rather, to "conquer" it somehow via climbing, diving, parachuting, rafting......you get the point-action! These groves and indeed special places everywhere will not withstand these hoards for long.
As a leader of the tree climbing community and speaking for it, I could write a book in response to what you've said. We understand and agree with your concern to preserve all life forms in and around trees, any trees. Without question. But I have to disagree with one point: In general it is not recreational tree climbers who are destroying our natural environment by trying to "conquer" the big trees. In fact the "conquer" mentality doesn't exist among recreational tree climbers. Never has. (We've worked very hard to keep it that way.) And there are not and never will be "hoards" of tree climbers in the redwoods, and certainly not in the national parks, where tree climbing is prohibited. Given the inherent dangers of and advanced knowledge required for climbing superlative trees, very few people are attempting it. When they do, they go with people who know (in the safety and "preservationist" sense) what they are doing.
I would venture to say that as a group, tree climbers climb trees for the sheer enjoyment of being "close to nature." Like members of the NTS, many of us are arborists and/or life-long naturalists. As a group, tree climbers are acutely conscious of our responsibility to preserve and protect the natural world and the trees we climb. We understand the fragility of life in the treetops, and we select our trees and our methods of climbing accordingly.
It may be that the in pictures you're seeing of ropes and apparatus used to climb the big trees, the gear belongs to the researchers who are exploring and documenting the tropical canopy. These researchers, too, are well-known for the caution and care with which they do their work. You probably agree that this work is very important not only to advance our understanding of life at the top of the forest, but also in bringing new awareness of the importance of forests to millions of people.