It depends whom you ask to. For many trees, definitely yes, as humans have been devastating forests for thousand of years, since the beginning of agriculture and urbanization. For some plants, like rice, corn, potatoes and others, humans are enablers, as they helped these species to propagate to unexpected levels, in order to feed themselves or their animals. For species of trees that depend upon bees to pollinate them, humans are basically stupid, as they are causing bees to disappear at alarming rates, putting the trees in grave danger, which in turn makes things more difficult to humankind. For the giant Sequoias of the Pacific Northwest of the United States, humans were a disgrace that almost caused caused their extinction, due to predatory and irresponsible logging.
The disproportionate enlargement of the brain on Homo sapiens, coupled with the development of advanced language, and the subsequent new forms of social structure allowed humankind to transform itself into a new kind of being that is now re-shaping the old natural order of the entire planet. No wonder humans see themselves as the masters of the universe, and are already thinking into explore other planets. They forget that they cannot live without plants.