R.I.P. Carl Leopold

 This post was contributed by ESA Science Policy Analyst Piper Corp.   Carl at the shack. Photo: Aldo Leopold Foundation Archives.  On November 18, 2009, A. Carl Leopold, son of the celebrated ecologist Aldo Leopold, passed away at his home in Ithaca, New York, at the age of 89. Carl Leopold was an accomplished plant physiologist and World War II veteran, and he carried on the legacy of his father as an active conservationist. He was a founder and director of the Aldo Leopold Foundation, the founding president of the Finger Lakes Land Trust, and co-founder of the Tropical Forestry Initiative.  As a teenager, Leopold worked with his family to restore the natural landscape on their Wisconsin River farm, a transformation that his father famously chronicled in A Sand  County Almanac.  Carl Leopold’s own writings include the seminal plant physiology text Auxins and Plant  Growth (1955), the textbook Plant Growth and Development (1964), and several articles on the scientific process and the relationship between science and ethics. Leopold’s diverse career included appointments as Graduate Dean and Assistant Vice President for Research at the University of Nebraska, Senior Policy Analyst on the staff of the Science Adviser to the President during the Ford Administration, and William H. Crocker Scientist at the Boyce Thompson Institute for Plant Research (an affiliate of Cornell University). After his retirement, he remained active in science, conservation, and public service-he was a strong voice against horizontal drilling and toxic waste storage in the Marcellus Shale, and a volunteer at a local food pantry. He was at work on two papers when he passed away, one on memory in plants and one on Wisconsin phenology.  Leopold will be remembered as an inspired scientist and an eloquent ambassador of his father’s land ethic. In a piece commemorating Leopold’s life, the authors wrote: Carl grew up with strong personal roots in the natural world and in the Land Ethic of his father and after growing his own youthful sapwood, colorful heartwood, and thin latewood, Carl became a mighty and graceful trunk that nurtured and enthusiastically supported many plant physiologists and conservationists who consider themselves to be “Leopold leaves” on the tree of Carl’s life....

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TNT and plants: shrubs as toxin detectors

Photo courtesy of Julie Naumann. If you’ve been to many national forests, chances are you’ve seen signs like the one to the left: walk on this field and a land mine might explode. In her talk this morning at the ESA Annual Meting, Julie Naumann of the U.S. Army Corps of engineers explained that even if they don’t explode, these buried capsules of TNT and other explosives are bad news for plants. Land mine capsules aren’t made to withstand weathering, and as a result, TNT powder can leach out of buried mines and into the soil. Naumann wanted to know what effects this leaching had on plant physiology. She raised individuals of common wax myrtle, a shrub that grows freely on land mine fields in coastal Virginia, and exposed their soil to a range of TNT concentrations. Not surprisingly, the plants showed significant signs of stress, including closing of stomates – tiny holes that act like plant nostrils — and reduced photosynthesis. The stressed-out plants didn’t just keel over and die, though.  All of the plants except for the ones exposed to the highest TNT concentration recovered their stomatal conductance, or the passage of gases and water through the plants’ stomates. “A lot of the TNT is stored in the plants’ leaves,” said Naumann. “There, it’s metabolized into less toxic compounds.” So, if the plants can suck up toxins in the soil, get sick for awhile, but then recover, could we use them as toxin filters in areas where soils are contaminated – in scientific terms, phytoremediation?  In this case, Naumann doesn’t think so. She points out that you can’t just walk out onto a mine field to plant and water vegetation, and that doing so repeatedly by helicopter would be prohibitively expensive. But she does think that the plants could be good indicators of other toxins. “Plants could be a useful tool for detecting anthropogenic stresses in soil,” she...

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