The last few decades of ecological investigations have produced a budding discipline of study on invasive biota. These organisms are identified normally as exotic to areas in which they invade, suppressing or out-competing native biota. These organisms’ spread and potency are normally linked to human activity, e.g. species being captured in cargo ship ballast water and subsequently spread to other regions of the world when the ship discharges ballast water.
The shores of the Flaming Gorge Reservoir in northeastern Utah, bordering Ashley National Forest, is blanketed with invasive plants, from the sudden fall of the lake level due to dry seasons and use for irrigation. These invasives are the most prolific colonizers, outracing native species that are further limited by the overstocking of cattle. These cattle are placed onto public land leased to private ranchers to obtain a yield from the land. The U.S. Forest Service sprays fields of identified invasive plants with toxic herbicide mainly to increase or improve grazing area for cattle, not preserve some historical environmental quality. The invasive plants in Ashely National Forest are particularly located around drained areas from the flaming gorge reservoir decrease, disturbance from cattle, logging activities, and cleared land for campgrounds/paths. Each of these activities is plainly linked to a direct human activity. When I scaled a mountain peak in the Uintah Wilderness I saw invasive thistles littering the trail up the ridge, and had to question how successful any attempt to remove these plants could even be feasible.
After a summer of tracking down, mapping, and digging up invasive species in Ashley National Forest, I feel convinced that we need strongly to reconsider our ideas about what these plants are doing and how they come to be. Invasive plants do indeed have an established scientific history of environmental detriment, but somehow we imagine that these organisms in-and-of themselves are malevolent forces trying to dominate ecological communities and ruin what we see as the better, more natural state of the landscape, that is untouched, unaffected, and unchanging.
The rhetoric taken by scientists and federal land managers portrays invasive plants as exotic outsider which is perpetually defiling a “native” landscape with which we are charged in protecting. The obvious irony is that the exotic groups causing the most disturbance are the environmental management organization (Department of Agriculture, Forest Service, Bureau for Land Management, etc.) in the post-colonial state. To only use the language “native” and “exotic” seems to make a mockery of the long and bloody North American history of exotic humans pushing out/oppressing the indigenous communities, as though white scientists have some right now to decide what is native to this land based on only a few decades of ecological information. In Invasion Biology: Critique of a Pseudoscience, David Theodoropoulos describes this history of conflating xenophobic tendencies with environmental management to produce oppostional attitudes to invasive plants as intities that must be erradicated, rather than indicators of deep ecological problems for which human communities are the culprit. He also shows through rigorous scientific review that the field of invasion biology is in fact not in concensus on the nafarious effects of exotic species, and that the kind of spread we see in invasive species is documented in many plant species as common through history.
A Permaculture lecture by Geoff Lawton I attended in Portland in July 2007 finally elucidated and articulated a different point of view on invasive species that, oddly enough, seems more objective and relavent that the majority of what is considered serious, rigorous ecological science publications. He proposed viewing invasive plants as a response to especially disturbed conditions in which primary pioneer species, i.e. those species first to colonize an area, take root in spaces early in the successional chain. He pointed out that invasive plant roots are typically excellent at breaking soil compaction, responding to harsh conditions, and slowly improving conditions for other late successional plants, e.g. shrubs, trees). This perspecitive is dangerous in one respect since it may suggest that we should have a hands off approach a let things run their course, possibly to a dangerous end–what if the successional chain becomes stuck in cyclic invasive annuals? But this perspective also allows for the tangible two fold consideration that 1) the problem is the orginal distubance itself and that 2) the lack viable native flora would require postive ecological efforts by human communities in cultivating and planting native plants that are suppressed not by invasives, but by our activities.
The federal government is pouring a great deal of money into the eradication of invasive species under the guise of native species protection. I would hope that we can stop the demonization of these species identified as exotic or invasive and focus on reducing our destructive activies on land (e.g. releasing rivers by removing dams and decreasing cattle stocks on federal land) and focusing on the kind of native plant stimulation and cultivation proposed by restoration ecologists.
