The Trees in McLaren Park
• • • • • • • • June 3, 2024 • • • • • • • •
Some of your letter writers feel pain at the select removal of trees in McLaren Park. I understand because I don’t like to see healthy trees removed.
But there are reasons for the removals. Note it is the Natural Resources Division (NRD). Its charge is to maintain or restore natural features and processes. There is nothing natural about the imposition of trees in what was a rich biological community of grasses and wildflowers. Those grasses and wildflowers have been drastically reduced in terms of variety in numbers and extent, and the NRD works very hard to save what’s left, including special biological communities—such as riparian (ie, streamside)—like Gray Fox Creek. This type of community is exceedingly rare in the City, and we should be grateful to NRD for providing habitat for animals and plants pressed to the margins.
I would like to speak up for the well-run Natural Resources Division. It has a strenuously difficult job but is severely underfunded. To boot, it now has to cope with the vicissitudes of climate warming and fiercely compete for funding with myriad social problems. The staff is knowledgeable and dedicated.
Removal of the weedy species is necessary—and yes, trees can be weeds just like other life forms. All plants have natural predators in their native ranges, but landscape plants imported from, say, across the ocean, left their predators there.”
Two corrections of misstatements in the article:
1. The NRD is scrupulously aware of other animals and their needs and thoroughly aware of bird nesting. NRD routinely contracts with professionals to check and recheck this issue before proceeding with a project.
2. It is not true that people are opposed to this project. I find that as people’s understanding of such issues increases, they become more accepting and supportive of the NRD. At the Commission hearing on April 18, public support was expressed for the project, and there was no opposition.
If people want to understand why native plants and natural processes are important, here is a brief summary that I delivered to the recent Commission meeting:
The City is fortunate to have a Natural Resources Division to protect its diminishing natural resources. Staff is energetic in managing the hundreds of species of plants and animals that have been here for thousands of years and which form the basis of its rich biodiversity. Because of competition from weeds, there are fewer and fewer native plants and animals every year. The understaffed NRD is hard-pressed to slow the loss.
Removal of the weedy species is necessary—and yes, trees can be weeds just like other life forms. All plants have natural predators in their native ranges, but landscape plants imported from, say, across the ocean, left their predators there. The energy the plants capture from the sun does not enter the food chain, but instead goes into proliferation—biomass and seed production, which overwhelms the native plants that share their energy with the food chain. That food chain is all the organisms that would not exist if the native plants didn’t exist. Critters quaff their nectar and pollen, eat their leaves, suck their juices, eat their seeds, or gnaw at their roots. That is how natural ecosystems work, and they produce the natural world we love—and weeds contribute little or nothing.
San Francisco has been famous in natural resource circles for the great diversity of its natural resources. We have planted a city on top of it which has severely damaged that diversity—many species of plants and animals no longer exist in the City, and one, the Xerces blue butterfly, is extinct. But an amazing number of species are hanging on, and will continue to with our help.
Jake Sigg is an environmentalist living on the Westside.
June 2024
