Tuesday, December 28, 2010

Les Mehrhoff - botanist and pioneering giant in the field of invasion biology

Picture courtesy Randy Westbrooks
SCC Camp
Les Mehrhoffbotanist at the University of Connecticut, and a pioneering giant in the field of invasion biology, has passed away leaving ecosystems a little less protected and all of us a much more beholden to his work in championing biological diversity.   Doing justice to his work fills a web site and attempting to describe the reach of his work will be a task for future historians of ecology and horticulture.  But, perhaps the towering monument to his life's work is the creation of The Invasive Plant Atlas of New England - the  IPANE project - whose mission is a testimony to his drive to protect the last native landscapes.


From early detection and rapid response, to high tech mapping by citizen scientists, Dr. Mehrhoff worked tirelessly to find new ways to offset the harm caused by invasive species.  He sought to understand how the mechanisms of invasion worked and how one might use the knowledge to prevent further damage.  Focusing on plants, Les was determined to find a way to protect the indigenous species of New England and North America and eventually the world.  Les spoke to me about the impact of ornamental horticulture on native plant communities, about claims of sterility and about ways of assessing a consensus about the valuation of ecological systems.

The disappearance of species and the homogenization of place concerned Les Merhoff.  He studied the effect of invasive species on ecological interactions in natural areas.  He sought to understand the impact of introduced species on the rate of species loss in non-managed natural systems.  He was a leader both in the on the national stage as well as a visionary to grassroot-movements that struggle to reverse the tide of ecosystem altering invasive species.  Les was like a gardener who did not need to wait for more information when considering the removal of a weed from a favorite display.  He saw first hand the changes that were happening with greater and greater speed to the native flora and therefore ro whole ecosystems.

Today, the political winds have shifted, and the invasive species conversation has been pushed to the local level.  There is no effective national conversation today, but rather a rising tide of citizen scientists who owe much to Les Mehrhoff's tenacity and determination to organize and train citizen scientists to help stem the flood of invasive species into native species communities.  Because interest groups have stifled any near term hope of an effective national management strategy, state and local activists are creating regulations and legislation to begin to address the impacts of invasive species.


Les would have been proud to see action rather than talk; in his shadow the work goes on.

Saturday, December 04, 2010

Invasive species – quietly change our world

    Invasive species cause problems for us. Invasive species issues are a member of the set of current "really" big problems that we consign to the realm of national or global politics but react to locally and personally. At some level most of us understand that when we participate in the global market we are facilitating the homogenization of the world's human cultures and biological systems. Our needs and desires conspire to demand produce and products to address our current conditions in a more cost effective way; that is we ask for more choices at lower costs. This market force creates pathways of products and systems to move them cost effectively through out the world. In order to drive down the costs the pathways externalize some of the operational costs on to the global environment including the opportunity costs of the accidental or intentional introduction of a novel species into a local ecosystem or even our personal space.     We condone this externalization of costs in the global market because we feel that nature has several qualities that allow us to do so at no cost. These qualities include a feeling that nature is in some sense infinite and its forces are asymmetrically arrayed against human activities. In other words, the force of nature can overwhelm and reset any small imbalance that may arise from our dumping or moving market-place excesses from one ecosystem to another. Simply put we have a history of dumping unwanted or unneeded things over the garden fence into wild, natural areas in the knowledge that nature will somehow decompose this refuse. With such thinking a small animal, insect, or plant that accidently comes with our latest consumer needs in the shipping packing and escapes into our natural areas is of no immediate consequence, and in the long term will be absorbed by the overwhelming infinite forces of nature.
    Another quality of nature that comes into play for many of us is the idea that human artifice enhances or betters the "work' of nature. This idea reflects the view that nature is waiting for us to add value through human activities and technology. Nature is a resource to be exploited (in a positive sense of the word) for the well being of humanity. In order to support the growing population of the world, technology will have to reset and reorder natural processes for it is understood that the carrying capacity of the world's ecosystems as presently constituted are inadequate to projected increase in human population. In a local sense this is called development and falls under the politics of land use. The issue of the impact of an invasive species on a local system can seem to pale in consideration of the impact of a new shopping malls parking lot. The idea of saving the natural world is juxtaposition with the need to exploit its services for the betterment of mankind. In this scenario an invasive species is simply an early symptom of the change that is coming to the ecosystem and therefore the cost of prevention is too high and not justifiable.
    Invasive species are symptoms of humanity's footprint, and they are agents of environmental change . This dual nature makes it hard to pin them down for they can slip between the two concepts of symptom and agent. Because, quoting Bertrand Russell, everything is vague to a degree you do not realize till you have tried to make it precise, invasive species are conceptually so slippery that they provide no common basis for understanding or consensus. What this means is that even with a common set of :facts a stakeholder can arrive at equally valid but completely different outcomes. One view may lean towards denial of entry and presumption of caution tending to zero risk, while another would tend towards management of risk by setting on a level of acceptable impact. We ignore the ecosystem impacts that invasive species create because it suits our near term desires and our cost benefit analysis. With our heads firmly in the sand, a sturdy sense that technology will rescue us in a world overflowing with crises we take comfort in ignoring the quiet ecological alterations that we choose to ignore.