Key points are not available for this paper at this time.
Shackleton, C. M., T. Ticktin, and A. B. Cunningham. 2018. Nontimber forest products as ecological and biocultural keystone species. Ecology and Society 23(4):22. https://doi.org/10.5751/ES-10469-230422
Shackleton et al. (2018) studied this question.