Blowin’ In The Wind?
Climate change may influence the spread of breeze-born seeds
As climate change speeds up, British plants could be gone with the wind. Or not. In a new analysis, researchers explore how waning or waxing wind speeds across the United Kingdom in the future might alter the flow of gale-born seeds. And while uncertainties remain high, some plants, such as the native lizard orchid (Himantoglossum hircinum), could find themselves stuck, the team reports in the Journal of Ecology.
Many plants spread their seeds by letting them drift on the wind. But climate change promises to alter wind patterns, and a past study of North American trees suggested that doldrums brought on by climate shifts could alter their ability to adapt to a shifting climate. In the current study, researchers at the Centre for Ecology and Hydrology in Wallingford, England, dug up how British gusts might or might not similarly halt the flow of seeds.
The researchers first drew on 17 simulations of climate change for the years 2070-2099. They then incorporated demography data from three native British plants exclusive to the south of the island. They also included three non-native species, including the tree of heaven (Ailanthus altissimam), a Central European woody plant.
Not surprisingly, the 17 climate simulations tended to vary in their predictions of future wind speeds, the team reports, ranging from a 100% increase in velocities to a 90% slow-down. Wind speeds can be difficult to predict, simply because gales pick up or lose gusto as they flow over small-scale features like glens or hills. But the team spotted what looked to be the signs of an overall slow-down, since the median predictions fell around a 50% decrease in summer wind velocities.
That slow-down would likely be universally bad for the reproductive efforts of British plants, the team concludes. Populations of the lizard orchid, whose short stature means it has difficulty lofting its seeds into the fastest wind currents, for instance, normally shift only 100 centimeters per year. But with a projected wind decrease, that slow migration might squeak to a crawl, dropping to about 3 millimeters per year. And the team suggests that, like the characters in Alice In Wonderland, if the orchid can’t run, it will likely fall behind.–Daniel Strain | January 16, 2012
Source: Bullock, J.M., et al. (2012) Modelling spread of British wind-dispersed plants under future wind speeds in a changing climate [http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2745.2011.01910.x/abstract]. Journal of Ecology, 100(1) p. 104-115. DOI: 10.1111/j.1365-2745.2011.01910.x
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