Wildflower is published quarterly by the Wildflower Center. Its content is national in scope with articles about the conservation and use of native plants as well as news from the Wildflower Center. A subscription is provided to Wildflower Center members as a benefit of membership.
Razing Cane - Winter 2007
By Melissa Gaskill
Humidity is high on the Louisiana coast. Walking seems more like swimming, and the heat has a weight like prickly flannel as people who make up a small group wade through knee-high grass on a thin strip of land between the highway and railroad. They make slow progress, plucking tiny seeds from grass stalks and placing them in marked paper bags.
These are volunteers for the Coastal Louisiana Habitat Restoration Initiative, a major effort organized by the National Wildlife Federation (NWF) and funded by a grant from the National Fish and Wildlife Foundation with additional funds from Shell Oil. In 2005, according to the NWF, Hurricanes Katrina and Rita inundated tens of thousands of acres of this coastal habitat with salt water. Storm surges, masses of water pushed onto land by the hurricanes, tossed debris over forest, savanna and marsh. Powerful waves scoured grasses and other vegetation from thousands of acres, and howling winds flattened thousands of trees. Invasive species lost no time taking advantage of the loss of forest canopy, and some animals that weren't killed by the storm struggled to find food, clean water and shelter.
"Louisiana's coastal habitat and wildlife suffered a big hit," says Susan Kaderka, regional executive director for the NWF's Gulf States National Resource Center. "High water and winds from the storms pushed animals out of their habitat and destroyed many nesting sites. Tidal surges of salt water killed freshwater fish, alligators, amphibians and many other species. Food sources were destroyed."
The Coastal Louisiana Habitat Restoration Initiative plans to re-vegetate 500 acres of habitat, remove debris from another 1,000 acres and stabilize 12 miles of levee fronts. Native plants will be restored, re-creating wildlife habitat and protection from future hurricanes. This massive effort will involve a total of 2,500 people working 65,000 hours on more than 13 sites - collecting seeds, planting native species, removing invasive plants and debris, repairing trails and installing bird boxes. Working with 12 state and federal properties in south Louisiana, the project began in the summer of 2007 and extends through May 2008. Volunteers are recruited through the NWF website and hurricane relief work groups, including churches.
Fortunately, many people find this kind of volunteer work rewarding. "This is a fulfilling opportunity," says Rebecca Triche, senior coordinator for the Coastal Louisiana Habitat Restoration Initiative. "Volunteers will see real results and make a connection with nature."
In addition to manpower, successful restoration also requires the right plant materials, and for a sustainable effort, that means plants native to the area, says Scott Edwards, coordinator of the Acadiana Resource Conservation and Development Council in Louisiana. Cultivars not adapted to the state show signs of summer stress and are less vigorous, with lower biomass yields, he reports, than local variants of the same species. Plant materials best adapted to an area originate on the same site or nearby sites with similar physical and biological environments. Plants native to a particular area also ensure ecosystem and genetic integrity.
However, an abundant and affordable source of genetically appropriate seed of local origin is not always available. In this way, the hurricane restoration project - which involves replanting grasses in coastal areas - faces the same challenge as the Louisiana Native Plant Initiative. The latter has been collecting seeds from around the state for several years, with the goal of eventually releasing 25 native grassland species to the commercial market. Those 25 species would be a minimum for restoring Louisiana grasslands, sort of a "prairie in a can," says Edwards. "We're all in the same boat - there aren't enough seeds."
Fewer than 1,000 acres of historic grasslands remain in the state, isolated remnants squeezed between highways and railroad rights-of-way. Seeds for species inhabiting these relic grasslands are not commercially available, so seed collection is part of the coastal initiative. Post-hurricane seed collection will also benefit prairie restoration overall.
The Importance of Restoration
The knowledge that individual plant species are potentially beneficial to humans and the environment inspires organizations like the Wildflower Center to conserve single species. However, a species can't survive in a vacuum but needs a healthy system in which to grow. Therefore, restoration - healing and renewing damaged, degraded or destroyed ecological systems - is also critical.
With multiple species and myriad factors involved, restoration can be more daunting and complicated than conservation. The Center combines research with real-world experience to meet the challenge. Research seeks to understand attributes of various plants and how they can be used, while also exploring the usefulness and effectiveness of management techniques such as prescribed fire or mowing. Those lessons are then field-tested, often through outside consulting work, says Steve Windhager, Ph.D., the Wildflower Center's director of landscape restoration. On the flip side, questions raised in outside work can be the subject of research at the Center. While restoration can mitigate damage done by nature itself, as with the hurricanes, more often it is needed because of the actions of humans, such as overgrazing, mining or draining of wetlands.
Pure restoration returns an entire historic ecosystem, Windhager says, but that isn't always possible or even desirable. The context of a system must be considered. For example, river systems historically included periodic flooding, but that flooding can be a problem when restoring that river near a developed area.
Denise Reed, Ph.D., a coastal geomorphologist and professor at the University of New Orleans, agrees: "A wetland has channels, bayous, ridges and trees. It isn't just a flat, grassy plain. We are investigating the role of each of those things that make the system so valuable ecologically. You don't want to restore marsh to improve storm surge protection and lose some of those other really valuable things."
Restoration also must look at where a habitat is imbedded, considering all the species involved. "If there isn't enough space for warblers, for example, putting in the right trees wouldn't help," Windhager says. It boils down to using plants to solve a particular problem, whether that is bringing back a tall-grass meadow or dealing with urban storm water.
Restoration also can prevent the spread of invasive plants. A project at the Roy E. Larsen Sandyland Sanctuary, a Nature Conservancy property in the heart of southeast Texas' Big Thicket 20 miles north of Beaumont, has responded to damage from Hurricane Rita with restoration. Because the hurricane uprooted or snapped in two thousands of trees across the region, the resulting increase in sunlight from overstory canopy removal could make it easier for non-native plant species to invade. Restoration by the U.S. Forest Service and The Nature Conservancy focuses on managing the land to encourage re-vegetation by desirable plants.
"We're incorporating detection and treatment of any potential increase in invasive species into our ongoing restoration and management of native communities," says Wendy J. Ledbetter, TNC southeast Texas project director.
In a culture that has largely separated humans from nature, restoring landscapes is also a way to re-create a relationship with the land, Windhager adds. "It's a simplistic idea that human activity in nature is bad and the best we can do is minimize it. If that's the best we can do, then we're in a heap of trouble."
Determining whether or not a restoration is successful depends on the system being restored and the goals for a particular effort. There are quantitative measures, such as those being used in the Louisiana initiative. "Success could also be when you don't have to plant that next generation," Windhager says. "Reproduction in the system is a good indicator."
Determining when a project is finished is equally complex. "Some people say restoration is complete when the system doesn't need any input from humans," says Windhager. "I think that goes back to that fallacy of divorcing ourselves from nature." He considers sustainable interaction more realistic - perhaps prescribed burning or limited re-seeding, at much less effort and expense than the initial input.
There is an inverse relationship between the time set for a project and its cost, Windhager says. "If you start a project that your great-grandchildren will finish, it won't cost much. If you need it to be far along next year, it will cost a lot."
Often the work must be done in stages, rather than all at once. In a woodland, for example, desired trees might grow only in the shade, so step one is to plant faster- growing trees to provide shade, with the desired species coming later. In Louisiana, collecting seeds in the wild was followed by propagating plants to produce more seed, and then only much later putting plants in the ground.
Ongoing interaction is part of that relationship with the landscape, however, which can be a good thing. "With the Louisiana projects, say you flew in to help, and then you go home, but you keep up with the project," Windhager says. "Or you go back every year and appreciate it by hiking the trails. You're establishing a relationship. It doesn't have to be about action all the time. It's recognizing that there will be appropriate actions and roles for humans, watching out for when it is time for you to act and then taking action. The other thing is that restoration is a partnership between humans and nature - and that means some things are out of your control."
Like hurricanes. And humidity.