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In the USA, the United States Department of Agriculture (USDA) Natural Resource Conservation Service (NRCS) has restored millions of acres of wetlands through its Wetland Reserve Easement (WRE) programs. However, few quantitative studies have explored whether WREs have enhanced wetland hydrology and wetland plant communities. Additionally, USDA Compatible Use Permits for cattle grazing and other management practices are sometimes issued for WREs, but little is known about potential benefits/detriments of such practice on the success of wetland restoration. In this study, we tested if hydrological restoration of previously drained species poor pastures increased water depth and hydroperiod. Restoration involved plugging key ditches, adding water control structures and a berm. We also tested if hydrological restoration increased plant diversity (alpha and beta), floristic quality (using coefficient of conservatism) and increased the cover of wetland species (using species wetland status). Finally, we tested if cattle grazing had an effect on the success of restoration by comparing grazed plots to fenced plots. We studied two conservation easements (a total of 748 acres) located on semi-native pastures in central Florida, USA. We monitored vegetation using permanent transects stratified by vegetation type before (2004–2005) and after (2012) the restoration (2008). We assessed wetland hydroperiod using groundwater wells set up in 2003 and located within and outside the boundaries of these two easements. We used linear mixed models and multivariate analyses to compare vegetation and hydroperiods pre- and post-restoration. Number of flooded days increased following restoration in one of the easements, but we did not detect significant changes in hydrology in the other easement. Floristic quality, beta diversity and cover of obligate wetland species increased in both conservation easements and in most vegetation types. These vegetation changes were likely due to restoration activities since annual rainfall was not significantly different pre- and post-restoration. Cattle grazing did not have a negative or positive effect on the success of restoration, nor did we detect any positive effect of grazing on the success of restoration. Overall, our study shows that hydrological restoration can enhance wetland hydroperiod, water depth and wetland vegetation, but more resources should be allocated to short- and long-term monitoring of the restoration success. [ABSTRACT FROM AUTHOR]

Grazing lands and rangelands are increasingly recognized as an important alternative to other developed land uses for sustaining ecological communities in Florida, the rest of the southeastern United States, and other regions. It is important to understand factors that influence ecological communities on private grazing lands, especially in areas with abundant wetlands, which are often sensitive habitats. This study examined the effects of different vegetation types and simulated grazing (clipping) on the abundance, diversity, and composition of the invertebrate community in seasonally flooded, isolated wetlands on a cattle ranch in south-central Florida. We compared invertebrate communities in wetland areas dominated by two different types of vegetation: emergent macrophytes (Pontederia cordata [Pickerelweed]) and grasses (primarily Luziola fluitans [Southern Watergrass]). There was a trend toward greater abundance and diversity of invertebrates in grass-dominated communities. Experimental removal of vegetation to simulate heavy grazing significantly decreased the abundance and diversity of invertebrates. It also shifted the community composition of invertebrates to favor members of Diptera and Ostracoda. Management practices in grazed wetlands that use light or intermediate levels of grazing, or that foster a greater diversity of vegetative cover, may support more diverse and populous wetland invertebrate communities. [ABSTRACT FROM AUTHOR]

Exotic earthworms from Europe and Asia are invading many northern forests in North America that currently lack native earthworms, providing an opportunity to assess the role of this important group of invertebrates in forest ecosystems. Research on earthworm invasions has focused on changes in soil structure and carbon (C) and nitrogen (N) cycling that occur following invasion. These changes include the mixing of organic and mineral soil horizons, decreases in soil C storage, and equivocal effects on N cycling. Less well studied are changes in the soil foodwebs that accompany earthworm invasion. Soils of north temperate forests harbor a tremendous diversity of microorganisms and invertebrates, whose distribution and abundance can be substantially altered by earthworm invasion. Furthermore, invasive earthworms can affect understory plant communities, raising concerns over the loss of rare native herbs in some areas. The ecological consequences of earthworm invasion are mediated through physical, geochemical, and biological effects. These effects vary with different earthworm species, as well as with the characteristics of the site being invaded. Earthworm invasions may have important interactions with other rapid changes predicted for northern forests in the coming decades, including climate and land-use change, increased nutrient deposition, and other biological invasions. [ABSTRACT FROM AUTHOR]

Reports on the ecological and policy implications of an invasion of exotic earthworms in North America. Research of earthworm fauna by Gordon E. Gates; Classifications of earthworms; Ecological considerations; Effects of earthworm invasions; Risk of ecosystem disturbance; How to identify problematic species; Policy options.