National Agricultural Research Center; Invasive Species, Climate Change & Poison Ivy

The work of the people and programs of the Beltsville, Henry A. Wallace National Agricultural Research Center touches everything from food safety to the changing environment. For those interested in the world of invasive species and the intersection of native challenges and exotic problems, the research, which is threatened by the chronic under-funding for USDA/ARS Beltsville over more than a decade, is an invaluable tool in the struggle to create a policy of action.

The land mangers and keepers of natural areas wage constant war on exotic weeds, which they have labeled invasive species. The general property owning or using public battles aggressive plants, insects and diseases which threaten personal health or security, as well as traditional notions of beauty and order. Explaining that the native poison ivy, (Toxidendron radicans), is not invasive in the mid Atlantic is a semantic dialogue which, for too many, is a squabble over distinctions not readily understood. [pictures from my garden]

Because invasive species issues are connected to issues of environmental and climate change, the wicked inconvenience is that solutions which are single objective defined such as the prohibition of sale of non natives, leads to confusion and adamant opposition. The general public wants as its priority a safe, secure, serene, and, syntactically easy to understand landscape; the managers and wardens of natural areas seek a working, self-sustaining eco-system.

The cry for native only, begs the question, native to when and where; the change in climate may overwhelm the answer. And so the work of Dr. Zizka, and those committed to the exploration of our changing world is of national importance. If a native plant, which by definition is a constituent part of a greater whole and therefore deserves and needs to be allowed to live, is at the same time growing in its ability to cause personal harm, we face a disconcerting controversy which muddies the over all invasive species conversation.

My conversations surrounding invasive species inevitably raise the question of plant adaptability and the question of carbon dioxide concentration change on the biota of a eco-system. Thus, when presenting invasive species issues to the general public, I am challenged to juggle harm to natural areas, change in plant diversity, climate change and its impact on the presumption of native, and the traditional definition of a weed. Because each stakeholder subliminally understands the complexity of invasive species issues, they result inevitably to using their goals to define for themselves what an invasive species are. Hence, for the traditional majority gardener, poison ivy is an invasive species, and English Ivy an ornamental workhorse. For the managers of natural areas, the reverse, of course, is true.

And so the work of BARC, continues to provide information necessary to the development of strategies to protect ourselves in the here-and-now and in the not-so-distant future. In order to grasp the hierarchies of complexities generated by the small/quick changes we see in our gardens and properties and, to which we feel we can react with some confidence, and the big/slow changes, which happen beyond our life horizon, we are dependent to some extent on the work performed at the national agricultural laboratory.
How will the public react to the following information, which they will experience directly and painfully when they work or play outdoors?

Although the data on poison ivy come from controlled studies, they suggest the vexing plant is more ubiquitous than ever. And the more-potent oil produced by the plants may result in itchier rashes. "If it's producing a more virulent form of the oil, then even a small or more casual contact will result in a rash," says Lewis Ziska, a plant physiologist for the U.S. Department of Agriculture in Beltsville, Md.
The latest research, led by Dr. Ziska, studied poison ivy plants in Maryland under different levels of carbon-dioxide exposure. One group of plants was exposed to about 300 parts per million of carbon dioxide -- about the same level found in the atmosphere in the 1950s. Another group was exposed to 400 parts per million of CO2 -- about the same level in the atmosphere today.
After about eight months, leaf size, stem length and weight and oil content of the plants raised at current carbon-dioxide levels were, on average, 50% to 75% higher than the plants under the 1950s conditions, according to the study, expected to be published this year in the journal Weed Science. Not only did the higher CO2 level double the growth rate, but it made for hardier plants that recovered more quickly from the ravages of grazing animals. [Climate Changes Are Making; Poison Ivy More Potent; June 26, 2007; Page D1]