Stashing seeds in 'Noah's fridge'
Researchers worldwide are collecting seeds from wild plants to guard against the ravages of climate change.
In a modest BUILDING with stuccoed walls made from bales of hay, scientists are working on an ambitious conservation project. They seek to create a "backup" of this area's – and the world's – wild plants.Skip to next paragraph
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Handful by sweaty handful, they collect seeds from plants in the hills around this city in southern California. Once cleaned and dried, the seeds are put into silver-colored, insulated envelopes. Half of the envelopes remain here at San Diego Zoo's Conservation and Research for Endangered Species (CRES); the other half crosses the Atlantic to the Millennium Seed Bank Project (MSBP) in Britain, the acting repository for all the world's wild plant seeds.
Unlike animals, which can theoretically move to more suitable climes, plants can only move as fast as their seeds disperse. But in today's human-dominated landscape, such obstacles as cities, agricultural fields, and highways could stop plant migration. Scientists worry that many plant species won't be able to adjust and will simply disappear. One-quarter of Earth's species, plants included, may vanish by century's end, says the latest report by the Intergovernmental Panel on Climate Change.
So as US lawmakers haggle over how to handle human carbon emissions and avoid what's widely considered a climate catastrophe in the making, seed-banking projects like the MSBP have moved ahead with a "hope for the best, prepare for the worst" approach.
The worry – and the hurry – is that species may disappear tomorrow.
"We don't know what benefits these plants will provide – sources of medicine, important food crops," says Kayri Havens, director of the Institute for Plant Biology and Conservation at the Chicago Botanic Garden, a contributor to MSBP. "If we lose them, we lose all of those options."
On the other hand, scientists hope that once the proverbial dust settles, reintroducing species to the wild will be possible. "Seed banking represents a great deal of optimism and hope for the future," writes Flo Oxley, program coordinator at the Lady Bird Johnson Wildflower Center at the University of Texas at Austin, also a contributor to MSBP, in an e-mail. "Why save a resource if there is no future for it?"
On May 22 – Biodiversity Day – MSBP vaulted its one-billionth seed, a sub-Saharan bamboo in danger of disappearing from its native range.
Working with more than 100 partners worldwide, MSBP has so far banked about 18,000 species from 126 countries. On track to meeting its goal of banking 10 percent of the world's flora by 2010, it hopes to bank another 45,000 by 2020. That would represent one-quarter of Earth's known flora.
Something about the 21st century has triggered a flurry of seed-banking efforts. In 2001, the US Bureau of Land Management inaugurated its Seeds of Success program, an effort to bank native US plants for restoration projects and a contributor to MSBP.
More recently, Norway announced the Svalbard Global Seed Vault on the Svalbard archipelago above the Arctic Circle. Buried in permafrost, the bank endeavors to keep seeds from humanity's 21 food crops safe from various possible catastrophes – war, blight, climate change, and an asteroid strike among them. The MSBP differs from the Norway effort in one crucial aspect: It seeks to preserve wild species with no immediate economic value. And it seeks to do so by preserving their genetic diversity.
Natural selection "selects" for the individuals within a species that do best in the present circumstances. If hot and dry weather prevails in a field of daisies, for example, then the individual plants that prefer hot and dry conditions will thrive and set seed. If cool wet conditions prevail, cold-loving individuals will prosper. Scientists think that the best way to preserve a species is to preserve its genetic variation – to ensure that any single species contains both heat- and cold-lovers, so to speak – and to give natural selection a greater number of options to "select" from.
"If we're looking at evolutionary processes with a changing environment, the greatest amount of diversity provides us the greatest number of genes to ensure filling niches," says Jonathan Dunn, the botanical conservation coordinator at CRES. So "the best way we can facilitate [plants'] ability to change is to maintain diversity."