Nature's guard and gardener


"What we know about plant diversity is very restricted indeed," Chicago botanist and evolutionary biologist Sir Peter Crane told a Women's Board audience downtown last Tuesday, "but of what we do know, the statistics are discouraging." Speaking on the International Day for Biological Diversity, which happened to fall one day before Carolus Linneaus's 300th birthday, Crane listed the myriad threats closing in on plants worldwide: habitat loss, invasive species, land exploitation, environmental changes brought on by fertilization, pesticides, and global warming. "Every place on the planet, even remote ones, is impacted by human activity," he said. "If it isn't cultivation or changes to the soil, it'll be climate change." Perhaps as many as 400,000 plant species exist on Earth, but scientists have documented only a fraction of them, and some they've seen only once. "Many are already rare when we find them, already fragile," he said. "The slightest perturbation causes problems, and we're perturbing the environment all the time."

Seven years after leaving the Field Museum's helm to become director of England's Kew Gardens, a job that earned him knighthood in 2004, Crane returned to the Field last year to study plant science and conservation. He also joined the U of C's geophysical-sciences faculty in part because, as he noted last week, conservation is increasingly linked to global physical forces like climate change.

But Crane did not come to the podium with only bad news. In the developing world, where rapid cultivation threatens whole landscapes, seed banks are helping to preserve native species for future propagation, and institutions like the Field Museum are working to produce quick inventories and conservation strategies in botanically rich regions such as South America and southern Africa. Crane also praised triumphs like Illinois's Midewin National Tallgrass Prairie, a reconstructed ecosystem an hour southwest of Chicago. "That, frankly, is the future of conservation," he said. "It's a very interventionist approach. Unfortunately, the days when we could put a fence up" and count on the land remaining untouched "are waning." Conservationists, he said, will have to become gardeners.


Photo: Sir Peter Crane gives Women's Board members a slide-show tour of botanical biodiversity.

May 30, 2007