The following passages concern a plant called purple loosestrife. Passage A is excerpted from a report issued by a prairie research council; passage B from a journal of sociology.

Passage A

Purple loosestrife (Lythrum salicaria), an aggressive and invasive perennial of Eurasian origin, arrived with settlers in eastern North America in the early 1800s and has spread across the continent's midlatitude wetlands. The impact of purple loosestrife on native vegetation has been disastrous, with more than 50 percent of the biomass of some wetland communities displaced. Monospecific blocks of this weed have maintained themselves for at least 20 years. Impacts on wildlife have not been well studied, but serious reductions in waterfowl and aquatic furbearer productivity have been observed. In addition, several endangered species of vertebrates are threatened with further degradation of their breeding habitats. Although purple loosestrife can invade relatively undisturbed habitats, the spread and dominance of this weed have been greatly accelerated in disturbed habitats. While digging out the plants can temporarily halt their spread, there has been little research on long-term purple loosestrife control. Glyphosate has been used successfully, but no measure of the impact of this herbicide on native plant communities has been made.

 With the spread of purple loosestrife growing exponentially, some form of integrated control is needed. At present, coping with purple loosestrife hinges on early detection of the weed's arrival in areas, which allows local eradication to be carried out with minimum damage to the native plant community.

Passage B

 The war on purple loosestrife is apparently conducted on behalf of nature, an attempt to liberate the biotic community from the tyrannical influence of a life-destroying invasive weed. Indeed, purple loosestrife control is portrayed by its practitioners as an environmental initiative intended to save nature rather than control it. Accordingly, the purple loosestrife literature, scientific and otherwise, dutifully discusses the impacts of the weed on endangered species—and on threatened biodiversity more generally. Purple loosestrife is a pollution, according to the scientific community, and all of nature suffers under its pervasive influence.

Regardless of the perceived and actual ecological effects of the purple invader, it is apparent that popular pollution ideologies have been extended into the wetlands of North America. Consequently, the scientific effort to liberate nature from purple loosestrife has failed to decouple itself from its philosophical origin as an instrument to control nature to the satisfaction of human desires. Birds, particularly game birds and waterfowl, provide the bulk of the justification for loosestrife management. However, no bird species other than the canvasback has been identified in the literature as endangered by purple loosestrife. The impact of purple loosestrife on furbearing mammals is discussed at great length, though none of the species highlighted (muskrat, mink) can be considered threatened in North America. What is threatened by purple loosestrife is the economics of exploiting such preferred species and the millions of dollars that will be lost to the economies of the United States and Canada from reduced hunting, trapping, and recreation revenues due to a decline in the production of the wetland resource.