How Resilient is a Landscape?
Collaborative efforts throughout the Southeast aimed at building more resilient landscapes have gained momentum in recent years, in part due to private and governmental initiatives and partnerships such as the Cohesive Wildland Fire Management Strategy. Much of the work is a continuation of years or even decades’ long efforts, while other work is in the beginning stages or even somewhat experimental in nature. In Southeastern Virginia - the northern extent for many “southern” species, land managers have been working on Longleaf pine (Pinus pallustris) restoration efforts, and in the process making discoveries about just how resilient the landscape really is.
Picture 1. A 2013 prescribed fire in a five year old planted Longleaf Pine stand at Chub Sandhill Natural Area Preserve. DCR Natural Areas Stewardship Manager Rick Myers speculated that this was the first fire of this kind on this kind of site in hundreds of years.
To help with those efforts, the U.S. Department of the Interior funded a Wildland Fire Resilient Landscapes project to help restore Longleaf communities in the Southeast. Working in collaboration with federal, state and private partners throughout the Southeast, the project funding is intended to help expand the use of prescribed fire, which is a vital component to restoration efforts. One of the hubs for the project is the U. S. Fish and Wildlife Service Region 5 South Zone fire program located at Great Dismal Swamp National Wildlife Refuge in Southeastern Virginia.
Agriculture or industrial timber production dominates much of Southeastern Virginia. Protecting existing conservation lands, and acquiring or repurposing lands by federal, state or non-governmental agencies and by individual landowners themselves, was the first step toward building resiliency back into the system. Much of the restoration work to date has consisted of simply reintroducing fire in habitats that used to burn frequently, but more recently, reforestation with Longleaf pine grown from the few remaining native Virginia seed sources has been added.
Over the past two centuries, the vegetative matrix of the sandy hills and ridges south of the James River, which once had an overstory of Longleaf pine and a rich and diverse understory, has changed completely. The Longleaf were cut and fire had been excluded for decades. Plant communities disappeared, or dwindled to a few isolated populations in niches scattered across private or public lands- remnants of habitats lost to land conversion and fire exclusion.
Longleaf pine is part of a resiliency puzzle, and the rare plants intermixed in the understory are indicators of ecosystem health. With Longleaf essentially extirpated from Southeastern Virginia, restoration has required intensive management and a concentrated effort on the part of many agencies and landowners to prepare sites and plant Longleaf seedlings.
Getting the proper site conditions often means taking aggressive actions. Harvesting the existing trees (most often Loblolly pine) on a site is usually necessary, followed by prescribed fire to prepare the site. If the site had already been harvested and allowed to grow up, techniques such as drum-chopping and burning become necessary prior to planting. Once prepped and planted, Longleaf have done very well.
Fire remains an integral part of its success however. Naturally-occurring fire is relatively rare and unwanted in this area, therefore agencies and landowners across the region have been using prescribed fire with increasing frequency to mimic natural processes. The Resilient Landscapes project funding will help support burning at sites such as the Zuni Pine Barrens, Big Woods Wildlife Management Area, and the South Quay Natural Area Preserve, and other sites that have the potential for the restoration of Longleaf and rare fire-dependent plant communities.
Continuing a cycle of regular fire is vital to maintaining these habitats and maintaining the resiliency that the habitats provide. The success of these efforts over the past 10 years has shown the ability of species to thrive as they once did in the past. Within a relatively few fire returns, rare plants that were restricted to small, isolated subpopulations, or in one case had not been seen or surveyed in 70 years, began appearing, and in some cases spreading and flourishing. These plant populations were indicators not only of a habitat that once was, but also of a habitat that could also be restored to some extent.
On the Zuni Pine Barrens site, managed jointly by the Virginia Department of Conservation and Recreation’s Natural Heritage Program and Old Dominion University, approximately 450 acres have been restored to Longleaf, and regular fire applications over the past 15 years have reinvigorated this former Longleaf pine habitat. An example of a positive plant response as a result would be the sandywoods chaffhead (Carphephorus bellidifolius). Since the implementation of an aggressive fire regime, plant numbers have gone from countable to uncountable (thousands). Other plants such as pixie moss (Pyxidanthera barbulata) have also shown a similar response. While many of these plants have a wide distribution, their relative scarcity from sites in Virginia is indicative of the change in both habitat conditions and natural processes such as fire.
Picture 2. Carphephorus bellidifolius sandywoods chaffhead
For areas with relatively undisturbed soils, some rare plants still persist, but are suppressed by a dense canopy and deep litter layer. They get an occasional release from a tree harvest, but are quickly suppressed again once the canopy closes and any reproduction they manage results in seeds falling into a litter layer instead of the soil they need to germinate. A good example of this is again at Zuni Pine Barrens, where pale grasspink (Calopogon pallidus) disappeared from the state for 70 years and then showed up again after 10 years of burning modified the canopy and removed much of the litter layer.
More recently, sandywoods chaffhead has been observed in the recently-acquired South Quay Natural Area Preserve, where an additional 650 acres of Longleaf have been restored. The first prescribed fire entry on the property occurred in September 2015, and it is expected that the South Quay site will follow the example of Zuni in terms of plant response as fire is reintroduced. Some early indications of response are encouraging, and land managers suspect that with regular application of fire there will be some exciting discoveries in the years to come.
These reappearances of state or globally rare plants are positive signs that the areas are responding to management efforts. Their rebound is a good indicator that the landscape as a whole is becoming more diverse and healthier overall. For some sites and species however, the question of what comes back and what doesn’t can only be answered by time, patience, and careful management planning and action.