Winter soil temperature at the snow cover manipulation experiment in boreal forest

The study was conducted in a spruce forest near Syktyvkar, taiga zone of northwestern Russia (N 61.650429, E50.731707). The mean annual air temperature is 0.5 C, with an annual precipitation of about 620 mm. Snow cover duration is averages 6 months (November-May). The stand is dominated by Norway spruce (Picea abies), but other species including Betula pubescens and Populus tremula are interspersed. There are sparse shrubs of rowan (Sorbus aucuparia) and dog rose (Rosa canina). The herbaceous layer is dominated by Oxalis acetosella and Vaccinium uliginosum. Less abundant herb species are Maianthemum bifolium, Pyrola rotundifolia, and mosses Hylocomium splendens, Pleurozium schreberi, Rhytidiadelphus triquetrus. In November 2018, three experimental plots (3 × 6 m) were established. The distance between the plots was at least 100 m. Each plot was divided into two sub-plots (3 × 3 m); each sub-plots corresponded to one option. The first option provided for the absence of snow cover in winter, which was achieved by the construction of sheds (a wooden frame covered with polyethylene film). The height of the sheds was 1 m. The fallen snow was regularly removed from the sheds to prevent their destruction. The second option was the control and did not involve any manipulations. The soil temperature was recorded eight time a day from November 2018 to May 2019 using a HOBO U12-008, ONSET, which was installed 5 cm below the soil surface at each sub-plot.

本研究于俄罗斯西北泰加林带瑟克特夫卡尔（Syktyvkar）附近的云杉林内开展，地理坐标为北纬61.650429°、东经50.731707°。该区域年均气温0.5℃，年降水量约620毫米，积雪持续时长平均为6个月（11月至次年5月）。林分以挪威云杉（Picea abies）为优势种，伴生有柔毛桦（Betula pubescens）和欧洲山杨（Populus tremula）。林下稀疏分布有花楸（Sorbus aucuparia）和犬蔷薇（Rosa canina）灌丛。草本层优势种为山酢浆草（Oxalis acetosella）与湿地越橘（Vaccinium uliginosum）；较稀少的草本物种包括二叶舞鹤草（Maianthemum bifolium）、圆叶鹿蹄草（Pyrola rotundifolia），藓类物种则包括塔藓（Hylocomium splendens）、赤茎藓（Pleurozium schreberi）及三角叶提灯藓（Rhytidiadelphus triquetrus）。2018年11月，研究人员设置3块3×6米的实验样地，样地间距不小于100米。每块样地被划分为2个3×3米的亚样地，分别对应两种处理方案。第一种方案为冬季移除积雪：通过搭建棚架（木质框架外覆聚乙烯薄膜）实现，棚架高度为1米，需定期清除棚架上的积雪以防止结构受损。第二种方案为对照组，不施加任何人为干预。2018年11月至2019年5月期间，采用HOBO U12-008型（ONSET公司）土壤温度记录仪，在每个亚样地地下5厘米处安装设备，每日记录8次土壤温度。