The majority of the world’s species cannot withstand any significant disruption of their habitat by humans. Healthy ecosystems depend to a great extent on old and gnarly places, that might take centuries to develop, and are rich in what ecologists call “spatial heterogeneity”: complex natural architecture. They need, for example, giant trees, whose knotty entrails are split and rotten; great reefs of coral or oysters or honeycomb worms; braiding, meandering rivers full of snags and beaver dams; undisturbed soils reamed by roots and holes. The loss of these ancient habitats is one of the factors driving the global shift from large, slow-growing creatures to the small, short-lived species able to survive our onslaughts. Slow ecology would protect and create our future ancient habitats.
There’s no substitute for an ancient tree, or an ancient anything else.