Gardening the Earth

Every year when I go to pull weeds in “my” prairies or my “eco-island” in Wagner Natural Area I ask myself whether what I am doing isn’t a total waste of time. The progress I make is a bit like that of classical Penelope, wife of Odysseus, who spun her cloth by day only to undo it all again at night. (Cherry Dodd hit the biological nail on the head when she said that the way to tell the weeds from the natives is that the weeds are the plants growing the fastest!)

Nevertheless, I refuse to give up, as do many of us, encouraged perhaps by the fact that, as a result of humanity’s gradual realization of the devastation its activities have wrought upon natural communities, reclamation and restoration have become something of buzzwords. Governments, from regional to international, now sanction restoration, even if expertise lags woefully behind intention. It is therefore something of a shock when you find that there is already a pushback against these struggling infant sciences, hardly out of their diapers; that there are people with a vested interest in abandoning if not killing them.

Some of the opposition of course is passive rather than aggressive; it comes from people who don’t know the difference between a native plant and an alien: who call anything that isn’t deliberately cultivated as a horticultural species either a weed or, more generously, a wildflower. But at least one North American group with a blog condemns all restoration efforts and attempts to recruit others to its way of thinking. This is the Milliontrees group, which formed to oppose the cutting down of a forest of Eucalyptus trees in the San Francisco Bay area by conservation authorities to make way for the recreation of an original oak-savanna community. Milliontrees have since expanded their campaign to oppose the cutting down of all trees (one argument for this of course is that trees store carbon), to “send up” weeds as contributing to biodiversity and to protest the use of herbicides in controlling them. They argue against all forms of restoration, and discredit native plant advocates whom they call derogatively “nativists.” To do this, they comb the scientific literature systematically for statements and research that support their arguments. Some of what they say is indeed valid, but because they are ideologically driven it is biased. (Of course, they accuse the nativists of being similarly ideological.) They do not deny that human action has caused the loss of native communities but they counter that current man-altered ecosystems are the new normal for nature, that the natives and exotics have adapted or will adapt to each other, and that in any case man is part of nature! Whether this advocacy group is unique, or whether there are others like it showing weedy growth, I know not, but I am concerned that they will too easily win a gullible public to their essentially anthropocentric viewpoint. (They say that nativists are “misanthropic.”)

Given these assaults on the rationality and effectiveness of what we in the Edmonton Native Plant Group do, it is reassuring to learn that what some professional botanists say seems to support our efforts, however minuscule these might be in the grand scheme of things. Stephen Blackmore and David Paterson, horticulturalists at the Royal Botanic Garden, Edinburgh, believe “gardening” with natives (or, as they call it, “gardening the Earth” can make an important contribution to conservation of biodiversity. They recognize that “the continued survival of healthy populations of species in their natural environment is universally regarded as the ideal outcome of conservation” but note that “except (for) the relatively scarce tracts of wilderness, careful intervention is at least necessary and often essential.” Botanic gardens can help guide restoration efforts by acting as living collections and a source of DNA, providing practical experience in growing techniques, and indicating what species will grow where, now and in the future. The authors note also the importance of maintaining biodiversity in urban and agricultural landscapes as more people migrate to the cities. Plant conservation done outside of natural, protected areas is known as ex situ conservation, and they believe that botanic gardens contribute to several targets of the Global Strategy for Plant Conservation, an initiative of the Convention on Biological Diversity (2002). One target aims to preserve “60% of threatened plant species in accessible ex situ collections, preferably in the country of origin, and 10% of them included in recovery and restoration programmes.” This viewpoint feeds into an even larger target, that of achieving a sustainable planet. What we do in ENPG has nothing like the scientific robustness of a botanic garden project, of course – though perhaps that’s something we need to strive for – but maybe, contrary to what Milliontrees think, we pursue the better course.

Blackmore, S. & D.S. Patterson. “Gardening the Earth: the contribution of botanic gardens to plant conservation and habitat restoration. Ch.18 in Taxonomy and Plant Conservation. 2006. Edst. Etelka Leadlay & Stephen Jury. Cambridge, U.K., Cambridge University Press. Pp. 266-273.