A few days ago, we attended a talk by Peter Kareiva, chief scientist at the well-known Nature Conservancy. (He’s also been elected a member of the National Academy of Sciences.) It’s an environmental organization that prides itself on being science-based; it has some 600 working scientists. Kareiva’s argument was that environmentalism is painting itself into a corner. It’s becoming polarized, misanthropic, dogmatic, and anti-technology. And it’s losing support: In 2011, over half of people surveyed agreed with the statement, “Most of the people actively involved in environmental groups are extremists, not reasonable people.” Back in 1996, Kareiva said, under a third had agreed with that. It’s seen as a preoccupation of the wealthy and the white: the image of an environmentalist is a woman who wears lots of green, is moneyed, and preaches…

NATURE: RESILIENT, NOT FRAGILE

Kareiva took issue with the use of the term “fragile” as a cliche when discussion anything eco-related. Fragile planet. Fragile river. Fragile ecosystem. Fragile species.  This tends to extremist thinking, because if it’s fragile, it will break; there’s no room for compromise. Battles are hard fought and divisive. Spotted owl vs loggers. Fish vs humans. In Uganda, some 5,000 villagers were evicted from a “fragile” habitat rich in fauna to create a reserve — and naturally, created passionate opposition as well. When a political change allowed the villagers to return, they slaughtered the animals to get rid of the wildlife that had attracted conservationist attention. The villagers didn’t want to take the risk of being dispossessed of their land again. But nature isn’t fragile, Kareiva points out. It’s resilient. He gave a number of examples:

• Mount St Helens, the volcano that in 1980 blew with the force of 10 Hiroshimas and destroyed the surrounding forests and ecosystems — which started to rebound almost immediately.
• Bikini Atoll, site of nuclear bomb tests until 1958, now has 25% more coral than before (possibly due to excluding humans from the radio-active island).
• Chernobyl Exclusion Zone, 30 kilometers in radius round the area of the 1986 nuclear accident, is a haven for wildlife including the endangered Przewalski’s horse.
• In San Francisco city, peregrine falcons are breeding. This bird nearly went extinct owing to DDT contamination, but has now recovered.
• In Indonesia, orangutans were found thriving in palm-oil plantations, not just in virgin forests.

The threats of imminent danger can be compelling for donors; Kareiva showed a full-page advertisement taken out by several conservation groups indicating the Chinook salmon could be gone by 2017 without action to save them by removing dams. The Nature Conservancy looked at the science behind it, and were unconvinced. But talking later with his counterpart in one of the organizations, Kareiva was told, “Last year was our best fund-raising year.” Extinctions are unfortunate, but not necessarily disastrous. “It’s not just going to stop, it’s going to change. What you’re left with is different” — not a collapse, but a different ecosystem.

• The American chestnut was a dominant tree in eastern forest, and rained down nutrients in the form of chestnuts. It was a hugely important element in the ecosystem. Then it died out — and the ecosystem changed as a result. It didn’t stop functioning as an ecosystem.
• The Passenger Pigeon was another thriving species, which by its sheer numbers much have had a major eco-system impact. The last bird died in 1914. The ecosystem changed to accommodate it.

[ETA: Interestingly, the Band-tailed pigeon, described by researchers as the western counterpart to the passenger pigeon, thrives and is not endangered. Bandtails apparently carry a host-specific passenger-pigeon louse that was thought to have gone extinct with the passenger pigeons.]

There are two views of ecosystems. One imagines it as a family, where each member is critical to the family, and irreplaceable; remove enough of  the members, and the ecosystem collapses as surely as a family would do. In Kareiva’s view, it’s more like an office: Everyone has a job to do, but if the person doing it leaves, someone else takes over. In this view, the species filling the vacant slot might be from inside the system, or outside it. It makes no functional difference. (Kareiva thinks we should not allow a species to go extinct — but also notes that it’s a value, a belief, and others might not share it.) There are no pristine places left in nature; the world now has more trees in plantations than in “natural” forests. Over half the world’s humans live in cities, and the trend is accelerating. A view of nature as a “rambunctious garden” makes compromise possible.

A PRAGMATIC APPROACH TO NON-NATIVE SPECIES

When asked about introduced species, Kareiva pointed out that California has 25% more plant species than before. Owing to non-native plants, bio-diversity has actually increased. From a practical viewpoint, too, non-native plants serve functions that the native plants no longer perform, such as holding soil or providing habitat. [We’ve noted some local examples in an earlier post, Interwoven and Integrated: Non-native and Native in Life’s Web.] Nevertheless, Kareiva believes it makes sense to try to police the frontiers: be careful about which species are allowed entry. Some introduced species — like the emerald ash borer — have been a problem. Island ecosystems are particularly vulnerable. But battling non-native plants that have become established can be pointless, counterproductive, and fail the cost-effectiveness test. His preferred approach is set out in a blog post on the Nature Conservancy website. It’s called Invasive Species: Guilty until Proven Innocent?In a thoughtful, balanced article he notes:

Science-based conservation cannot be about knee-jerk platitudes and simple views of good and evil. Policy experts and conservationists who have been working hard to control invasive species should not discourage arguments about invasive species — the fact is we cannot control all invasive species, and in many cases, yesterday’s invaders have become plants and animals that are beloved by local people.

[ETA: 4 July 2011 – This talk, Conservation in the Real World, was sponsored by The Long Now Foundation, and is available as a podcast on their website.  Audio is free to everyone; the same talk is also available as video to members.]