Oakland's Draft Urban Forest Plan

Rather than volunteers, please TRAIN & HIRE local neighborhood residents to provide ongoing maintenance and education.

West macarthur as well. Telegraph from 40th Street heading toward pill hill and downtown

The scientific definition of biodiversity includes both native and non-native plants. In Oakland, and much of coastal California, excluding non-native trees would severely limit tree species. The pre-settlement landscape of Oakland was 98% grassland and coastal scrub. (see David Nowak, “Historical vegetation change in Oakland and its implications for urban forest management,” Journal of Arboriculture, September 1993) There were only about 10 species of native trees in pre-settlement Oakland. Now there are over 500 species of trees in Oakland according to the UFP, which are predominantly non-native. We plant non-native trees in Oakland because they are adapted to the current climate and site conditions that are not suitable for our limited number of native tree species. There is little evidence that wildlife is dependent upon native plants in California. Butterflies are perhaps the most conspicuous example of wildlife that are using non-native plants as their host plants and as sources of nectar. “California butterflies, for better or worse are heavily invested in the anthropic landscape [altered by humans]. About a third of all California butterfly species have been recorded either ovipositing [laying eggs] or feeding on nonnative plants. Roughly half of the Central Valley and inland Bay Area fauna is now using nonnative host plants heavily or even exclusively. Our urban and suburban multivoltine [multiple generations in one year] butterfly fauna is basically dependent on ‘weeds.’ We have one species, the Gulf Fritillary that can exist here only on introduced hosts. Perhaps the commonest urban butterfly in San Francisco and the East Bay, the Red Admiral is overwhelmingly dependent on an exotic host, pellitory. And that’s the way it is.” (Professor Arthur Shapiro (UC Davis), Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions (University of California Press, 2007)

I appreciate the perspective of the commenter who requests more native trees. I'd like to offer a different perspective as an ISA certified arborist and landscape architect living and practicing in Oakland. The urban conditions present in today's Oakland are very different from the conditions in which native trees evolved (soils, paving, microclimate, hydrology, etc.). Climate change adds to this disparity. In order to make cities livable (and protect native habitat outside of cities) we need to use both native trees and non-native trees. When working in a dense, urbanized environment like Oakland, creating safe, comfortable, beautiful cities for people should be the top priority. The benefits of robust tree canopy to humans are profound and shouldn't be undermined by an insistence on using only native trees. Humans need habitat too. ;)