when a hotspot heats up

This morning’s LA Times had a cover story on a groundbreaking study that offered some pretty dire projections for the future of California’s 5,500-plus native plant species should the current global warming proceed apace.

The findings by several scientists affiliated with universities in California and beyond were just published in PLoS ONE, one of the rare online scientific journals that allows everyone access for free. Here’s the abstract of the article:

The flora of California, a global biodiversity hotspot, includes 2387 endemic plant taxa. With anticipated climate change, we project that up to 66% will experience >80% reductions in range size within a century. These results are comparable with other studies of fewer species or just samples of a region’s endemics. Projected reductions depend on the magnitude of future emissions and on the ability of species to disperse from their current locations. California’s varied terrain could cause species to move in very different directions, breaking up present-day floras. However, our projections also identify regions where species undergoing severe range reductions may persist. Protecting these potential future refugia and facilitating species dispersal will be essential to maintain biodiversity in the face of climate change.

The authors (Loarie, et alia) say that the current species that can travel quickly from one generation to the next could move their ranges northward or uphill in response to warmer, dryer weather. That gives some hope for species as a whole, particularly those that have seeds that can travel on the wind or easily hitch a ride in the tire tread of a Hummer.

Bristlecone at Great Basin National Park

Left: Ancient bristlecone pine at Nevada’s Great Basin National Park. Photo on Gorp [ source ]

But what does that bode for individual plants like the ancient bristlecone pines that you find on mountaintops throughout the Great Basin, plants where some individuals are magisterial homebodies that have been estimated to be nearly 4,000 years old? Unfortunately, those single plants that were adults in Roman times and saplings in the days of Egypt’s Amenhotep the First will face a less certain future.

The authors offer hope that habitat preservation could help compensate for the forces of global warming. Still, I worry. How good a job have we done in the past to preserve habitat?

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