"The Invasive Species War" by Leon Neyfakh ran in the "Ideas" section of The Boston Globe July 31, 2011. Click here to read Neyfakh's article.

Ted Elliman, New England Wild Flower Society's Vegetation Management Coordinator, prepared the following response for the Society and submitted it to the editors of The Boston Globe:

To the Editor:

From reading "The Invasive Species War" by Leon Neyfakh in the July 31 Ideas Section of The Boston Globe, readers could have the impression that conservation biologists have declared war on all non-native, naturalized plant species in the country.  That impression would be mistaken.  The target of our efforts is the subset of non-native plants that have invaded and persisted in natural habitats such as forests, wetlands, and ponds, to the detriment of native plants and the animal species that co-exist with them in those habitats. To take Massachusetts as an example, introduced species now account for over 40% of the flora growing without cultivation in the state.  Of the 898 non-native plants listed in "The Vascular Plants of Massachusetts" as established in the state, 66 species, less than 1% of the total, are identified by the Massachusetts Invasive Plant Advisory Group as invasive or potentially invasive in natural habitat conditions.  

To be clear about definitions: native species are those that are indigenous to a certain area.  In the case of Massachusetts, native plants are those whose natural range has included the state since pre-colonial times.  Non-native, or introduced species are non-indigenous species that have been moved to an area outside of their natural range as a result of human activities; and invasive plants species are those non-native species that disrupt and degrade the ecological diversity of natural habitats. 

Japanese barberry, glossy buckthorn, multiflora rose, oriental bittersweet, garlic mustard, Japanese knotweed, purple loosestrife, Phragmites, Eurasian water-milfoil, and water chestnut are among the introduced, invasive plants that have over-run natural landscapes, diminishing their native plant associations and ecological diversity.  According to Neyfakh’s article, some biologists view with admiration the spread of these invasive plants as hardy newcomers (are the same biologists, for similar reasons, equally approving of the emerald ash borer, the hemlock wooly adelgid, the chestnut blight, and the Norway rat?), but one must then ask why they are not just as successful in their regions of origin.  A large part of the reason is that the herbivores, insects, pathogens, and competing plants that have co-evolved with these species are absent here, and, without these checks on their growth, invasive plants have a competitive advantage over native species which must cope with a host of natural controls.  Until these controls appear in our natural landscapes, and, in the short-term, there is little chance that they will, invasive species will thrive at the expense of native species.

There is no question that the spread of invasive species has been caused by human impacts on the natural environment.  The plants are here because people have introduced them, deliberately or by accident, and they have spread to a large extent in response to human-related disturbances. But now that they are here, progressively invading, simplifying, and degrading natural ecosystems, how should we respond?  For many of these species, there is little chance that they can be completely controlled, but does that mean, as some scientists and social scientists cited in the article suggest, we should let it happen, and accept, for example, woodlands dominated by Japanese barberry, glossy buckthorn, and garlic mustard as novel ecosystems having the same ecological value as the native trees, shrubs, and wildflowers they have displaced?  

We have been fortunate in our work to join forces with hundreds of volunteers who are distressed by the ecological damage caused by invasive plants in natural areas within their own communities, and who are determined to do something about it.  The goal of these invasive control efforts is not to recreate an imaginary, pristine state but to restore conditions for the recovery of native plants that had thrived before the habitat was overrun—in recent times—by invasive species.  As Douglas Tallamy, author of Bringing Nature Home has shown in his work, the removal of invasives and the restoration of native plant species has beneficial ramifications for entire ecosystems, with native insect and bird populations rebounding in response to native plant recovery.  

In our work on invasive control and native plant recovery, we try to keep in mind the principle stated so clearly by Aldo Leopold: "A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise."

Ted was not the only person to respond to this article. A member of the Society

Meg Muckenhaupt blogged her response to the article. Click here to read Meg's blog and the many supportive responses her blog elicited.