Integrative Biology Department, University of California at Berkeley, Berkeley, California, United States of America.
PLoS Biol. 2012 Jan;10(1):e1001247. doi: 10.1371/journal.pbio.1001247. Epub 2012 Jan 24.
Wetlands are among the most productive and economically valuable ecosystems in the world. However, because of human activities, over half of the wetland ecosystems existing in North America, Europe, Australia, and China in the early 20th century have been lost. Ecological restoration to recover critical ecosystem services has been widely attempted, but the degree of actual recovery of ecosystem functioning and structure from these efforts remains uncertain. Our results from a meta-analysis of 621 wetland sites from throughout the world show that even a century after restoration efforts, biological structure (driven mostly by plant assemblages), and biogeochemical functioning (driven primarily by the storage of carbon in wetland soils), remained on average 26% and 23% lower, respectively, than in reference sites. Either recovery has been very slow, or postdisturbance systems have moved towards alternative states that differ from reference conditions. We also found significant effects of environmental settings on the rate and degree of recovery. Large wetland areas (>100 ha) and wetlands restored in warm (temperate and tropical) climates recovered more rapidly than smaller wetlands and wetlands restored in cold climates. Also, wetlands experiencing more (riverine and tidal) hydrologic exchange recovered more rapidly than depressional wetlands. Restoration performance is limited: current restoration practice fails to recover original levels of wetland ecosystem functions, even after many decades. If restoration as currently practiced is used to justify further degradation, global loss of wetland ecosystem function and structure will spread.
湿地是世界上生产力最高和最具经济价值的生态系统之一。然而，由于人类活动，在 20 世纪初，北美、欧洲、澳大利亚和中国存在的湿地生态系统中，有一半以上已经消失。为了恢复关键的生态系统服务，人们广泛尝试进行生态恢复，但这些努力对生态系统功能和结构的实际恢复程度仍不确定。我们对来自世界各地的 621 个湿地地点进行荟萃分析的结果表明，即使在恢复努力一个世纪之后，生物结构（主要由植物组合驱动）和生物地球化学功能（主要由湿地土壤中碳的储存驱动）仍然平均分别低 26%和 23%，与对照点相比。恢复要么非常缓慢，要么受干扰的系统已经朝着与对照条件不同的替代状态发展。我们还发现环境设置对恢复速度和程度有显著影响。大面积湿地（>100 公顷）和在温暖（温带和热带）气候下恢复的湿地比小面积湿地和在寒冷气候下恢复的湿地恢复得更快。此外，经历更多（河流和潮汐）水文交换的湿地比洼地湿地恢复得更快。恢复性能有限：即使经过几十年，当前的恢复实践也无法恢复湿地生态系统功能的原始水平。如果目前的恢复实践被用来证明进一步退化是合理的，那么全球湿地生态系统功能和结构的丧失将继续蔓延。
