At the Forest Service Southern Research Station (SRS), ecologists are working hard to manage the land in order to mitigate changes we’ve stimulated in the climate. Models for the region predict more varied and extreme rainfall patterns. Based on data gathered at Coweeta Hydrological Laboratory in western North Carolina, temperatures have, in fact, significantly increased since the 1980s and over the past thirty years have been more frequently severely wet or dry. As the climate changes, so does the precipitation, and both, it seems, are becoming less stable.
For lead scientist Chelcy Ford the problem is one of managing the extremes. To investigate the problem, he and his colleagues at the SRS have focused on precipitation patterns in forested land, and for a very simple reason: forests are a major source of freshwater, an understanding of how climate change and forest management affect streamflow, and thus the water supply, is crucial to our own future survival.
The idea may at first sound novel, but its logic is plain and deliberate: the way we manage our forests can drastically influence how vegetation handles, in the case of too much precipitation, excessive streamflow and, in the case of too little, its scarcity. According to Ford, the influence is unambiguous. Replacing deciduous trees with evergreens, for instance, “produced the largest effect on available surface water,” indicating that, in wet years, when precipitation is rampant, this management strategy would be promising: the year-round needles on pines diminish streamflow and thus help to prevent flooding. By contrast, in dry years, such a conversion would exacerbate the problem, as the pines would “worsen water shortages by reducing the amount of available water in streams.”
Bottom line? A forest’s design–what kind, and how much, vegetation–correlates both to the area’s water supply, a concern in times of both drought and deluge, and to its ecological health. The proper plants in the right places can avert deprivation and glut, while the wrong ones can induce them.
For Ford and the scientists at the SRS, this research amounts to solving one problem that is, paradoxically, both simple and complex: in the face of more violent, frequent, and unpredictable climate change, how can we build the land to be both more durable and more pliant? As the adage goes, the rigid branch breaks in strong winds, but the supple one yields. Or, perhaps more to the point, we always can, and should, in times of difficulty, cultivate our garden. Voltaire did, and he was eminently wise.
Discussion Question: What other factors should be considered prior to replacing deciduous trees with evergreens or vice versa?
News Article: http://www.sciencedaily.com/releases/2011/09/110928131806.htm
Journal Article: http://www.srs.fs.usda.gov/pubs/38726
Image Source: http://en.wikipedia.org/wiki/File:Aerial_View_of_Autumn_Forest_Colors.jpg
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