Responses of peatland vegetation to 15‐year water level drawdown as mediated by fertility level

作者：Nicola Kokkonen, Anna M. Laine, Jukka Laine, Harri Vasander, Kirsi Kurki, Jinnan Gong, Eeva‐Stiina Tuittila · 发表于：Journal of Vegetation Science · 年份：2019 · DOI：10.1111/jvs.12794 · 被引用次数：78 · 研究领域：Peatlands and Wetlands Ecology、Coastal wetland ecosystem dynamics、Botany and Plant Ecology Studies

Abstract Questions Peatland ecosystems are a globally important carbon storage that is predicted to turn into a carbon source due to water level drawdown (WLD) associated with climate change. The predictions assume stable plant communities but how realistic is this assumption? If the vegetation is not stable, what are the nature and rate of changes? Location Peatland complex in Southern Finland. Methods We conducted a water level drawdown (WLD of ~10 cm) experiment over 17 years in three peatland types differing in their fertility. On each peatland type, we included an adjacent forestry drained (FD, with water table ca. 40 cm lower than in control) area for comparison. Results Peatland type had a clear impact on the response to WLD: at the ecosystem level, the two minerotrophic fens underwent rapid species turnover, while the vegetation in nutrient‐poor bog was more resilient to change. In nutrient‐rich sites, WLD initiated tree canopy development and created understorey conditions that strengthened impact of WLD. In nutrient‐poor site, tree establishment was seen only in the FD area. In addition to high nutrient level, high wetness accelerated change at the plant community level, where we found three types of responses: accelerating change, decelerating change, and stability. Succession resulted in an overall loss of community heterogeneity. Conclusions Interaction between hydrology, nutrient availability, and biological factors in boreal peatlands is important: the drop in ...