Archbold Biological Station, Venus, Florida, United States of America.
University of Central Florida, Orlando, Florida, United States of America.
PLoS One. 2018 Jul 3;13(7):e0199333. doi: 10.1371/journal.pone.0199333. eCollection 2018.
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.
在美国，美国农业部（USDA）自然资源保护服务局（NRCS）通过湿地保留地 easement（WRE）计划已经恢复了数百万英亩的湿地。然而，很少有定量研究探索 WRE 是否增强了湿地水文和湿地植物群落。此外，USDA 为牛放牧和其他管理实践颁发了兼容使用许可证，但对于这种做法对湿地恢复成功的潜在益处/损害知之甚少。在这项研究中，我们测试了以前排水的物种贫瘠牧场的水文恢复是否增加了水深和水文期。恢复包括堵塞关键沟渠、增加水控结构和堤岸。我们还测试了水文恢复是否增加了植物多样性（alpha 和 beta）、植物区系质量（使用保守系数）和增加湿地物种的覆盖（使用物种湿地状态）。最后，我们通过比较放牧区和围栏区来测试牛放牧对恢复成功的影响。我们研究了位于美国佛罗里达州中部半原生牧场的两个保护地役权（共 748 英亩）。我们在恢复前后（2008 年）使用永久样带监测植被，样带按植被类型分层。我们使用 2003 年设立的地下水井评估湿地水文期，这些水井位于这两个地役权的边界内和边界外。我们使用线性混合模型和多元分析来比较恢复前后的植被和水文期。在其中一个地役权中，恢复后水淹天数增加，但我们没有在另一个地役权中检测到水文的显著变化。在两个保护地役权和大多数植被类型中，植物区系质量、β多样性和必需湿地物种的覆盖率都增加了。这些植被变化可能是由于恢复活动，因为恢复前后的年降雨量没有显著差异。牛放牧对恢复的成功没有负面影响，也没有发现放牧对恢复成功有任何积极影响。总的来说，我们的研究表明，水文恢复可以增强湿地水文期、水深和湿地植被，但应投入更多资源进行恢复成功的短期和长期监测。
