Black ash decline comes from underharvesting, not overharvesting

Evidence

In some parts of the range, basket makers began to observe a decline in the numbers of black ash. They worried that overharvesting might be to blame, a decline caused by too much attention for the baskets in the marketplace and too little for their sources in the woods. My graduate student Tom Touchet and I decided to investigate. We began by analyzing the population structure of black ashes around us in New York State, to understand where in the trees’ life cycle the difficulty might lie. In every swamp we visited, we counted all the black ash we could find and wrapped a tape around them to get their size. Tom cored a few in every site to check their ages. In stand after stand, Tom found that there were old trees and seedlings, but hardly any trees in between. There was a big hole in the demographic census. He found plenty of seeds, plenty of young seedlings, but most of the next age class—the saplings, the future of the forest—were dead or missing. … The other place where saplings were thriving was near communities of basket makers. Where the tradition of black ash basketry was alive and well, so were the trees. We hypothesized that the apparent decline in ash trees might be due not to overharvesting but to underharvesting. When communities echoed with Doonk, doonk, doonk, there were plenty of basket makers in the woods, creating gaps where the light would reach the seedlings and the young trees could shoot to the canopy and become adults. In places where the basket makers disappeared, or were few, the forest didn’t get opened up enough for black ash to flourish. … Black ash and basket makers are partners in a symbiosis between harvesters and harvested: ash relies on people as the people rely on ash. Their fates are linked. — Robin Wall Kimmerer, Braiding Sweetgrass, 517

Categorization

• XREF: Reverses the assumption that harvest harms species — links to ch29 food plants and humans shaping each other’s evolution, and to the mutual-taming idea of domestication.
• SEED: A conservation essay angle: ‘the species that needs harvesting’ — opening an ecosystem may be the care some species require; challenged ‘leave no trace’ environmental ethics.
• QUESTION: Does this underharvesting mechanism generalize to other culturally-keystone species, or is black ash special because baskets remove whole trees and open canopy?
• ADDENDUM: Directly extends the tree-as-infrastructure piece: human use of a tree species functioning as ecological disturbance that regenerates the forest.