Abstracts, Reviews, and Meetings

To develop the following abstracts, the editorial staff searches more than 100 scientific journals, professional and organizational newsletters, conference proceedings, and other resources for information relevant to ecological restoration practice and research. Please send suggested abstract sources to the editorial staff (ERjournal@aesop.rutgers.edu).

Grasslands

Using Livestock to Manage Plant Composition: A Meta-analysis of Grazing in California Mediterranean Grasslands. 2013. K.A. Stahlheber (Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA, stahlheber@lifesci.ucsb.edu) and C.M. D’Antonio. Biological Conservation 157:300–308.

The use of managed grazing has become a common technique for restoration of native plant populations in grasslands, but livestock effects on different plant groups have not been broadly quantified. What effect does grazing have on the cover, dominance and richness of native and exotic grasses and forbs? How are these effects influenced by soil, community type, soils, and grazing regimes? The authors addressed these questions using a meta-analysis of studies carried out in California grasslands with Mediterranean climate. They found that exotic forb cover increased uniformly and dramatically with grazing, but exotic forb richness did not. Native forbs increased in richness, but cover depended on precipitation and grazing regime. Cover by exotic grasses was unaffected by grazing, and was highly variable. Dividing up the studies by soil texture and taxonomy created groups that were too small to yield results with confidence. The authors conclude that grazing may be useful for enhancing native forb richness in some settings, but that it should be weighed against the potential for increased cover in exotic forbs. They recommend taking the current species pool and soil conditions into account when deciding whether or not to use grazing as a management tool, and caution that if few native species are found in a site due to prior agricultural use, grazing is unlikely to increase native diversity.

Season of Fire and Nutrient Enrichment Affect Plant Community Dynamics in Subtropical Semi-natural Grasslands Released From Agriculture. 2013. E.H. Boughton (MacArthur Agro-ecology Research Center, 300 Buck Island Ranch Road, Lake Placid, FL 33852, USA, eboughton@archbold-station.org), P.J. Bohlen and C. Steele. Biological Conservation 158:239–247.

Semi-natural grasslands with a prior history of agricultural grazing are diverse and under pressure toward conversion or abandonment. They are also increasingly included in conservation easements and other protected areas. In this study, the authors evaluate methods for managing this type of grassland to maintain biodiversity using grazing and burning. In an eight-year experiment, the authors investigated the effects of burn season and nutrient status on plant communities. They predicted that burning at the time of highest fertility would be advantageous to less competitive species, and that this effect would be most pronounced when grasslands were burned in summer, the historic fire season. They also predicted that in unburned areas, highly competitive species such as shrubs would dominate, displacing grasses and forbs and reducing diversity. They found that unburned, ungrazed plots had the lowest species richness and graminoid richness, while highest graminoid richness was highest in plots that were both burned and grazed in the winter, primarily due to sedges. In unburned plots, a native shrub (Eupatorium capillifolium) and a native forb (Lachnanthes caroliniana) became dominant and grasses declined. Plots burned in the winter became dominated by shrubs. The authors suggest that maintaining grassland structure in grasslands released from ranchland management in subtropical Florida requires burning, and that summer burning is most effective in reducing shrub encroachment and increasing graminoid and forb richness.

Creating Novel Urban Grasslands by Reintroducing Native Species in Wasteland Vegetation. 2013. L.K. Fischer (Technische Universität Berlin, Ecosystem Science/Plant Ecology, Rothenburgstr. 12, D-12165 Berlin, Germany, Leonie.Fischer@tu-berlin.de), M. von der Lippe, M.C. Rillig and I. Kowarik. Biological Conservation 159:119–126.

Grassland species have declined in many areas of the world. Restoration of grasslands has been undertaken in rural areas to counteract these losses. The authors of this study propose that additional potential for grassland restoration exists in cities, particularly in large-scale urban wastelands that are currently isolated from suitable species pools...