Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014,Finland.
Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu campus, P.O. Box 111, FI-80101, Joensuu, Finland.
Sci Total Environ. 2017 May 15;586:858-869. doi: 10.1016/j.scitotenv.2017.02.065. Epub 2017 Feb 16.
Restoration impact of forestry-drained peatlands on runoff water quality and dissolved organic carbon (DOC) and nutrient export was studied. Eight catchments were included: three mesotrophic (one undrained control, two treatments), two ombrotrophic (one drained control, one treatment) and three oligotrophic catchments (one undrained control, two treatments). Three calibration years and four post-restoration years were included in the data from seven catchments, for which runoff was recorded. For one mesotrophic treatment catchment only one year of pre-restoration and two years of post-restoration water quality data is reported. Restoration was done by filling in and damming the ditches. Water samples were collected monthly-biweekly during the snow-free period; runoff was recorded continuously during the same period. Water quality was estimated for winter using ratios derived from external data. Runoff for non-recorded periods were estimated using the FEMMA model. A high impact on DOC, nitrogen (N) and phosphorus (P) was observed in the mesotrophic catchments, and mostly no significant impact in the nutrient-poor catchments. The DOC load from one catchment exceeded 1000kg (restored-ha) in the first year; increase of DOC concentration from 50 to 250mgl was observed in the other mesotrophic treatment catchment. Impact on total nitrogen export of over 30kg (restored-ha) was observed in one fertile catchment during the first year. An impact of over 5kg (restored-ha) on ammonium export was observed in one year in the mesotrophic catchment. Impact on P export from the mesotrophic catchment was nearly 5kg P (restored-ha) in the first year. The results imply that restoration of nutrient-rich forestry-drained peatlands poses significant risk for at least short term elevated loads degrading the water quality in receiving water bodies. Restoration of nutrient-poor peatlands poses a minor risk in comparison. Research is needed regarding the factors behind these risks and how to mitigate them.
本研究旨在探讨林业排水泥炭地恢复对径流水质以及溶解有机碳（DOC）和养分输出的影响。共纳入了 8 个集水区：3 个中营养型（1 个未排水对照区，2 个处理区）、2 个寡营养型（1 个排水对照区，1 个处理区）和 3 个贫营养型集水区（1 个未排水对照区，2 个处理区）。其中 7 个集水区的数据包括 3 个校准年和 4 个恢复年后的资料，这些集水区都有径流记录。只有一个中营养型处理区报告了 1 个恢复前和 2 个恢复年后的水质数据。恢复措施是通过填埋和筑坝沟渠来实现的。在无雪期内每月或每两周采集一次水样；同时在同一时期内连续记录径流。冬季水质通过外部数据计算得出的比值进行估算。对于未记录的时期，采用 FEMMA 模型进行径流估算。在中营养型集水区，DOC、氮（N）和磷（P）的负荷影响很大，而在贫营养型集水区，这些养分的负荷影响则相对较小。其中一个集水区在第一年的 DOC 负荷超过 1000kg（恢复公顷）；另一个中营养型处理区的 DOC 浓度从 50mg/L 增加到 250mg/L。在第一年，一个富营养型集水区的总氮出口负荷超过 30kg（恢复公顷）。在中营养型集水区的一年中，铵态氮出口负荷超过 5kg（恢复公顷）。在第一年，中营养型集水区的磷出口负荷接近 5kg P（恢复公顷）。研究结果表明，对富营养林业排水泥炭地的恢复至少在短期内会对受纳水体的水质产生显著的负面影响，导致负荷增加。相比之下，贫营养型泥炭地的恢复风险较小。需要对这些风险背后的因素以及如何减轻这些风险进行研究。
