Ecological Restoration

Volume 25 Number 3 September 2007

Editorial

Is Sciencey A Word? by Mrill Ingram

Society for Ecological Restoration International

In The Year... by Keith Bowers

Articles

Success: An Unclear, Subjective Descriptor of Restoration Outcomes by Joy B. Zedler

The continuing development of the science of restoration is muddled by unclear and inconsistent use of the term "success." In recent issues of two journals, Restoration Ecology and Ecological Engineering, 116 papers employed the term to predict outcomes, judge outcomes, describe criteria for judging projects, or refer to an ecosystem attribute, all in the restoration context. Only ten papers used "failure." In this article I argue that ecologists can communicate with greater clarity and objectivity by omitting or clarifying the word success when publishing in the scientific literature. Many uses can easily be dropped (for example, compliance success can become compliance, and establishment success can be establishment). A common term, "restoration success" would be clearer if replaced with more specific terms (for example, project completion, achieving dense plant cover, supporting high species richness, or colonization by target species). At minimum, authors can define the term and use it consistently. When meant as a value judgment, it would help to say, "In my opinion, the project was a success" (or failure) and then specify on what basis the judgment was made. Thus, I recommend abstinence, substitution, and clarification of the term success to aid communication and help restoration ecology mature as a science.

Plant Community Response to the Decline of Diffuse Knapweed in a Colorado Grassland by R. T. Bush, T. R. Seastedt, and D. Buckner

Long-term reductions in invasive plant species are few, and studies documenting the response of plant communities to such reductions are equally rare. We quantified plant species richness and cover during a nine-year period at a grassland site in central Colorado where the introduction of biological control insects reduced the invasive non-native forb diffuse knapweed (Centaurea diffusa). This reduction opened up 25 percent of the relative plant cover for other plant species. Based upon repeated inventories of plant species from four transects at the site we found no changes in native or non-native plant species richness. Although we documented a modest increase from 2.4 percent to 8.6 percent in the relative cover of native forbs as knapweed declined, we observed no significant shifts in the relative cover of total native and total non-native vegetation. Two introduced grasses, field brome (Bromus arvensis [= B. japonicus]) and intermediate wheatgrass (Thinopyrum intermedium ) showed significant increases. Native warm- and cool-season grasses at the site were unable to exploit the vacuum left by the decline of the knapweed. We found little evidence of native grassland restoration following the reduction of a non-indigenous, invasive plant. Our findings support the conclusion that the reduction of a regionally abundant, non-native plant species alone is not sufficient to promote restoration of the former dominant native plant species, and that further management activities are necessary.

The Restoration of an Urban Floodplain in Rahway, New Jersey by Christopher C. Obropta and Peter L. Kallin

Please click here to see New Jersey urban park before and after pictures
The highly urbanized Rahway River watershed in New Jersey suffers from frequent flooding due to extensive development and destruction of riparian wetlands and floodplains. A diverse group of stakeholders worked together to restore a 1.8 ha site on the floodplain to riparian wetland with the goals of providing wildlife habitat, filtering pollutants from stormwater runoff, providing stormwater retention to minimize flooding, and providing public access for passive recreation as well as education about wetlands and watershed management. This wetland restoration site has been incorporated into the Union County Parks System as the Michael S. Bezega Wetlands Observation Area. Due to the urban setting (14 houses were removed from the site), the project design and implementation were very complex. Developing the water budgets required analyses of the tidal Rahway River as well as stormwater runoff from local drainage areas. Funding was obtained from six different funding agencies, and the project was constructed largely with city and county public works personnel. Native plants were installed by volunteers who continue to do invasive species management at the site. Key factors contributing to the success of this project include extensive involvement of a diverse partnership of stakeholders, a multi-disciplinary project team, thorough up-front design and engineering analyses, careful selection of vegetation palettes based on analyses of reference wetlands, and extensive on-site supervision of the construction crews by personnel who could make design decisions in the field.

Measuring Impacts of Restoration on Small Mammals in a Mixed-grass Colorado Prairie by Eric R. Stone

Small mammals in restored and native grassland plots were monitored at Rocky Mountain Arsenal National Wildlife Refuge in Colorado from 1997 to 2005 in order to measure the effects of restoration on small mammal communities. Variation in small mammal metrics (total captures, total biomass, and species richness) were related to both restoration efforts and interannual variation in weather. We compared remnant native grassland sites with restored grasslands and found that restoration plots experienced declines in the above measures following the initial alteration of soil and vegetation. However, abundance of some species and species richness also declined in control plots, probably owing to recent drought. We observed partial recovery of small mammals three to five years post-restoration. These findings suggest that timing and scale of restoration are both important considerations in maintaining small mammal communities.

Identifying Weed-resistant Bluebunch Wheatgrass for Restoration in Western Montana by Peter Lesica and Helen E. Atthowe

Invasive exotic plants often threaten the establishment of desirable plants in vegetation restoration projects. There is little understanding of the role of intraspecific genetic variation in resident natives in allowing or resisting invasions. Spotted knapweed (Centaurea maculosa [= C. stoebe]) is one of the most abundant invaders in western North American grasslands. We hypothesized that there was genetic variation in local populations of bluebunch wheatgrass (Agropyron spicatum [= Pseudoroegneria spicata]), a dominant native, for resistance to spotted knapweed and that we could identify resistant wheatgrass plants by locating isolated survivors in knapweed-infested grasslands. We planted clones of 12 "survivor" wheatgrass plants, four haphazardly chosen "unexposed" plants from uninvaded grasslands, and one cultivar (Goldar) selected for vigorous growth in a knapweed-dominated field and followed survival, growth, and reproduction for three years. We also raised clones of these same families in pots with knapweed in a complete randomized block design. Size, growth, and reproductive effort of wheatgrass plants varied among families in the field study where canopy cover of knapweed was more than 30 percent. Much of the variation among wheatgrass families was attributed to the superior performance of Goldar, which had greater growth, fecundity, and knapweed suppression compared with unexposed families in the field and garden studies. Our strategy for identifying knapweed-tolerant genotypes was ineffective; survivor families did not grow better than unexposed controls in the field or garden study. Our conclusion: developing local cultivars similar to Goldar by selecting for vigor and productivity among wild, local collections may be the best way to develop restoration cultivars that tolerate and suppress invasive weeds.

Rethinking Exotic Plants: Using Citizen Observations in a Restoration Proposal for Kings Bay, Florida. by Jason M. Evans, Ann C. Wilkie, Jeffrey Burkhardt and Richard P. Haynes

The Kings Bay, Crystal River complex, located in Citrus County, Florida, is one of the world's largest spring-fed ecosystems and a critical warm-water refuge for endangered Florida manatees. Unfortunately, large areas of Kings Bay are currently in a state of ecological degradation characterized by smothering mats of the filamentous cyanobacterium Lyngbya wollei. The causes of this ecosystem shift are not well understood, although it is often suggested that human-caused nutrient loading into the Bay combined with intermittent saltwater intrusions from storm surges may be responsible. In this article, we present results from interviews with local citizens, a review of aquatic plant literature, and research into the history of ecological change in Kings Bay. Our work indicates that management efforts to eradicate invasive exotic aquatic species may also have played an important role in the dominance of L. wollei. We suggest that future restoration efforts should follow a logic of "alternative stable states" that focuses primarily on the recovery of desired ecosystem functions and relaxes the assumption that exotic plants should be minimized. The Kings Bay case study points toward a more adaptive conception of ecological restoration, one informed by local knowledge and open to the utilization of established exotic plants as a tool for maintaining or restoring important ecological attributes.

Notes

Changes In Breeding Bird Abundance In Prairie Restorations (Illinois) by James R. Herkert

Restoring Rare Blackbelt Prairie (Mississippi) by Lisa McInnis

Successful Propagation of Dwarf Burr Ragweed (California) by David Bainbridge

Salmon, Forests, and Pre-Restoration Assessment Using Stable Isotope Analysis on Riparian Vegetation (Washington) by Jodi M. Minion, Dwight Barry, La Belle Urbanec, Ashley Gray, and Jeff Duda

Effects of Burning on Introduction of Rare Titusville Mint to a Protected Site (Florida) by Eric S. Menges and Suzanne Kennedy

Transplanted Seedlings Enhance Populations of Endangered Blowout Penstemon (Nebraska) by James Stubbendieck, Kay L. Kottas and Jay B. Fitzgerald

Book Reviews

Wildfire. A century of failed forest policy. George Wuerthner, editor. 2006. Washington, DC: Island Press. Cloth, $75. ISBN: 1-59726-069-X. Paper, $45. ISBN: 1-59726-070-3. 340 pages. Review by Paul H. Zedler