“Stopping San Francisco’s biggest land grab,” Sally Stephens, Dec. 4
Sally Stephens’s recent articles make flawed arguments regarding biodiversity and the motivation behind the Natural Areas Program.
First, the term “native” species is not “arbitrary,” as she would have your readers believe. It is a specific term used in conservation biology to distinguish species that have evolved over a long time span (often tens of millions of years) in a local area and that play an important role in the healthy functioning of the natural ecosystem.
Second, the “brown, treeless, scraggly landscape” she evokes is misleading. The coastal oak woodlands and dune ecosystems native to the region are not only beautiful in their own right, but serve a multitude of ecological functions, with thousands of species dependent upon them.
Finally, her rhetoric stating that conservation advocates are “anti-immigrant” is strange. There is no place for the term “anti-immigrant” in the science of biodiversity — we should stick with facts, not import the political catchwords of the day: Eucalyptus trees were initially planted in San Francisco under the misconception that their timber could be sold for profit; unfortunately, the dream of quick economic gain rapidly gave way to the reality that the wood was a worthless fire hazard and the trees invasive pests that have decimated the biodiversity of the forest.
These are by no means “natural” or “lush, green forests,” unless we thereby refer to their green leaves and ignore the actual composition and health of the forest. When hiking through Mt. Davidson and Mt. Sutro, virtually all one sees in these “forests,” aside from Eucalyptus, are two other invasive plant species: English Ivy and Himalayan Blackberry; both thrive among the eucalyptus leaf toxins that prevent native plants from growing.
Invasive species are those that spread rapidly and cause ecological or economic harm in areas where they are nonnative. As a conservation biologist, my primary concern is preventing ecological harm and therefore I, consistent with conservation values, strongly support the NAP restoration project. This project plays an essential role in helping to restore the natural environment once provided by oak woodlands and dune ecosystems; moreover, such restoration will enhance, rather than diminish or disturb, the experience of those who wish to hike in our parks.
Jennifer Dever, Ph.D.
Professor of Conservation Biology, University of San Francisco