DataSheet1_v1_Selection Cuttings as a Tool to Control Water Table Level in Boreal Drained Peatland Forests.PDF

Continuous cover management on peatland forests has gained interest in recent years, in part because the tree biomass with significant evapotranspiration capacity retained in selection cuttings could be used as a tool to optimize the site water table level (WTL) from both tree growth and environmental perspectives. This study reports WTL responses from six field trials established on fertile Norway spruce–dominated drained peatland forests across Finland. At each site, replicates of different intensity selection cuttings (removing 17–74% of the stand basal area) or clear-cut in parallel with intact control stands were established and monitored for the WTL for 2–5 postharvest years. The observed WTL rose after selection cuttings, and the response increased with harvest intensity and depended on the reference WTL; that is, larger responses were found during dry summers or in more southern location. Selection cuttings removing about 50% of the stand basal area raised the WTL typically by 15–40%. Using a process-based ecohydrological model, tested against data from the field trials, we show that the role of tree stand in controlling the WTL clearly decreases along the latitudinal climate gradient in Finland. This suggests that the potential of controlling WTL using selection cuttings is more prominent in southern than in northern Finland. Predictions with future climate (2070–2099) further indicated a general decrease of the WTL and that the importance of the tree stand in controlling the WTL will increase, especially in northern Finland. The results overall thus suggest that selection cuttings can be used as a tool to control the WTL in boreal drained peatland forests, and the potential is likely to increase in future climate.

近年来，对泥炭地森林的连续覆盖管理引起了广泛关注，部分原因在于，在选择性采伐中保留的具有显著蒸腾散失能力的树木生物量，可以作为优化场地地下水位（WTL）的工具，从树木生长和生态环境的双重角度出发。本研究报告了在芬兰富饶的挪威云杉占主导地位的排水泥炭地森林中建立的六个田间试验的WTL响应情况。在每个试验地点，设立了不同强度选择性采伐（去除17-74%的林分基面积）或与完整对照林并行进行的皆伐的重复试验，并监测了2-5个产后年份的WTL。观察到的WTL在选择性采伐后上升，且响应程度随采伐强度增加而增强，并依赖于参考WTL；即，在干旱夏季或更南部的位置观察到更大的响应。去除约50%林分基面积的选择性采伐通常将WTL提高15-40%。通过基于过程的生态水文模型，该模型经田间试验数据验证，我们展示了树木林分在控制WTL方面的作用在芬兰的纬度气候梯度上明显降低。这表明，利用选择性采伐控制WTL的潜力在芬兰南部比北部更为突出。对未来气候（2070-2099）的预测进一步表明，WTL将普遍下降，并且树木林分在控制WTL中的重要性将增加，特别是在芬兰北部。总体而言，结果表明选择性采伐可以作为控制北方排水泥炭地森林地下水位（WTL）的工具，其潜力在未来气候条件下可能增加。