Authentic Assessment: Habitat Restoration
“It is obvious that nature, or some part of it…, has intentions beyond this field and has made plans to travel with me” ~Loren Eiseley
The value of meeting an urgent, real world conservation challenge head on cannot be underestimated. For this reason, GLADE participants and MDC embark upon one of two possible restoration projects, both related to the extirpation of two species from the Drury-Mincy Conservation Area in Missouri. Since the recent ecological upset resulting in the extirpation of these two endangered species was fairly recent, the current situation provides an urgent conservation challenge that is both responsive to restoration efforts and resolvable in the foreseeable future.
Giant Cane Restoration
Swainson‟s Warbler (Limnothlypis swainsonii) is one of the most secretive and least observed bird species in all of North America. It once skulked through the canebrakes that lined vast ribbons of riparian habitat in southwest Missouri at the northern extension of its historical range. To the east, its loud song still echoes through the valleys of the Current River watershed. However, according to American Rivers (2011), this Ozark National Scenic Riverway is now designated as the tenth most endangered river system in the nation. The species also reproduces in Missouri‟s Big Oak State Park which, in the spring of 2011, was inundated by the Mississippi River as levees were breeched to save surrounding towns and villages. As a result, critical threats to this species remain.
Although Swainson‟s Warblers nest in rhododendron thickets and heavily wooded areas of southern Appalachia, nearly all nesting activity in Missouri is associated with the presence of Giant Cane.
(Arundinara gigantea). Homogeneous canebrakes are not enough to lure Swainson‟s Warblers into areas where they once nested. In addition to the cane, proper habitat must include a thick, heterogeneous understory with tangled vines and abundant leaf litter.
Today, Swainson‟s Warblers are absent from many areas of Missouri where they once enjoyed a sustainable population. The two main reasons given for the current endangered status of the species in the Drury-Mincy Conservation Area are: 1) the conversion of canebrakes to agricultural lands, and 2) the creation of reservoirs in the White River Basin. These human actions collectively destroyed vast tracts of Giant Cane habitat in the White River watershed leading to the steep population decline.
Without preservation and restoration of proper and available habitat, breeding Swainson’s Warblers in Missouri will soon be gone. GLADE organizers and other conservation agencies are working to prevent this tragic outcome and are hopeful that species’ distinctive song will return to the White River Glades Important Bird Area.
In the summer of 2009, GLADE‟s inaugural year, regional high school students participating in GLADE joined MDC employees in an effort to restore two additional acres of Giant Cane. Appropriately, they transplanted over 90 large clumps from the now established canebrake that GOAS volunteers transplanted only four years before. They created a more biodiverse habitat that could support Swainson‟s Warblers, other species of neotropical migrants, and abundant native life forms. Today, their 2009 work in restoring critical habitat continues to impact the lives of those original GLADE conservation interns.
Bachman‟s Sparrow (Peucaea aestivalis) is similar to Swainson’s Warbler in that it is a secretive bird that is seldom seen because of its skulking behavior amid the underbrush and grasses of its preferred habitat. Fire has played a major role in its survival, and suitable habitat is characterized by the scars of periodic burns. When fire suppression policies became widespread, Bachman‟s Sparrow numbers plummeted. Maintaining glade habitat suitable for Bachman‟s Sparrow and other xerophilous species in the Ozarks requires constant vigilance. Unfortunately, native Eastern Red Cedar has grown well in these unburned glade habitats, cutting off sunlight to and absorbing nutrients from the extremely shallow soils. In addition, invasive species such as sericea lespedeza, crown vetch, and multiflora rose have replaced native vegetation in areas once occupied by Missouri Bladderpod, Mead‟s Milkweed, Trelease’s larkspur, purple and yellow coneflowers, and native grasses and forbs, which provided the foundation for a biodiverse glade ecosystem.
Although fire is the most effective tool in the toolkit of the glade land manager, it is difficult to administer prescribed burns. They can only be prescribed within a very narrow range of weather conditions, and they require much human oversight. Because fire is dangerous and manual removal of cedars and other invasive plants can be helpful in lieu of burning, GLADE participants engage in the removal of species that prevent the emergence of desirable glade species. This requires that the GLADE students saw down cedars and carefully extract the invasive species.
At the time of this writing, the status of Bachman‟s Sparrow in Missouri is unknown, and many fear that it is currently extirpated from the state. Without preservation and restoration of proper habitat, breeding Swainson‟s Warblers in Missouri may be gone forever. As in the case of Swainson‟s Warbler, GLADE organizers and other conservation agencies are working to prevent this tragic outcome and are hopeful that Bachman‟s Sparrow will return to its former range in the White River Glades Important Bird Area.
An Antidote for Helplessness
These service-learning, restoration activities provide an antidote for the helplessness that many conservationists and concerned young people feel when confronted with the magnitude of global environmental challenges. Whether restoring cane or glade ecosystems, this invigorating day in the academy week firmly imprints the core GLADE principles and plants hopeful “seeds” into the lives of our young naturalists. In the deliberate act of joining together in hard work that is restorative, each individual’s sense of powerlessness is transformed into a warm kinship with fellow conservationists and a realization that humans truly can renew threatened habitats to positively impact wildlife.