Someone sent me a link to a thoughtful article in Slate magazine called “Don’t Sweat the Invasion” by
The author starts out with the example of tamarisk, also known as salt-cedar; it’s an “exotic invasive” that spreads along river-banks, and provides habitat for various birds. One of these is an endangered flycatcher.
Ironically, nativist thinking has encouraged the USDA to use imported (exotic, but who-knows-if-they’re-invasive) Asian leaf-eating beetles to kill the tamarisks by eating them to death. Theoretically, this allows native flora to return. Maybe. Anyway, in the interim, the nesting birds are straight out of luck. In March 2009, this led to a lawsuit by the Center for Biological Diversity and the Maricopa Audubon society.
The article uses this event as a springboard to look at the whole issue of nativist restorationism, and make some sensible observations.
“There’s an argument that even the dichotomy between “native” and “non-native” is ultimately meaningless. Species have always migrated; to identify one as native is to draw an arbitrary line in time.”
And something that’s particularly relevant to Sutro Forest:
“Once an ecosystem has absorbed a new species, any targeted intervention is likely to have significant ripple effects.”
Exactly. This forest has altered the microclimate, provided a habitat for birds and animals. This is what gutting the forest will destroy.
And frankly, it probably has as much bio-diversity as the iconic Muir Woods. Just because the “bio” comes with descriptors like Tasmanian, Himalayan, English, Scotch doesn’t reduce the numbers or the diversity.
There is extensive scientific research about tamarisk going all the way back to 1980. Here’s a couple of samples from the literature.
BL Everitt (in Wetlands, 1998) reported, “[Tamarisk] occupied land made available by the plow, the bulldozer, and the shrinking of the channel depleted of flow by upstream water development. Changes in both the physical environment and the native vegetation were well underway by the time tamarisk became widespread. There is no evidence that it actively displaced native species nor that it played an active role in changing the hydraulic or morphological properties of the river.”
Tamarisk is an example of many non-natives that are inapproriately accused of wiping out natives. They thrive where underlying conditions have changed. The natives disappear for the same reason. If you continue to eradicate the non-natives, the natives do not return unless the underlying conditions are reversed. If those conditions are not reversed you are left with NOTHING. No non-natives, no natives.
Likewise, BW Anderson (in Restoration and Management Notes, 1998) debunks the nativist myth that only native plants provide habitat for native animals. “As for the claim that salt cedar has little or no value to insects, birds, and mammals, that has been obliterated by available data.”
The native plant movement is dominated by hobbyists. They are not scientists and they are not using scientific data and information to support their agenda. The native plant movement is an ideology that is not supported by science. Yes, you will find an occasional Master’s degree in biology amongst them. That does not make them scientists. That makes them hobbyists armed with the ability to use scientific jargon to support their ideology.
If scientific arguments are insufficient to cast doubt on the nativist agenda, look at the results. They speak for themselves. Visit some of the so-called “natural areas” in the city that have been intensively gardened for nearly 15 years. Most are spectacular failures.