ENGAYU-TREES1: Hydrometeorological, subsurface, and snow data in Western Siberia near Salekhard of Yamal-Nenets Autonomous District, Russia, 2018-2021

Three observational sites (ENGAYU, RAI-IZ, LPTEG) were established in 2018 on the eastern slope of the Polar Urals range near the city of Salekhard of Yamal-Nenets Autonomous District, Russia. Each site contained four to five plots in the vicinity of about 1000 meters across a defined vegetation gradient, from the areas with tall and dense vegetation cover (FOREST), to the areas of tall and sparse vegetation (TREES), and to the areas of short vegetation dominated by sedges, mosses and dwarf shrubs (TUNDRA). At each plot, meteorological towers were erected and instrumented with above and below ground measuring equipment. The data was collected continuously from 2018 to 2021 with 30 to 60 min time interval. The data underwent quality assurance and data management protocols and were organized into three datasets: (i) subsurface and above ground observations (precipitation, air temperature, relative humidity, wind speed, four-channel radiation fluxes, net radiation, albedo, soil heat flux), (ii) below ground observations (temperature and soil water content at five depths up to 100 cm; temperature in the upper organic layer), and (iii) snow depth measurements. The data collection was a part of the project sponsored by the Office of Polar Programs (OPP) of the National Science Foundation (NSF). A specific goal of the project was to explore ecohydrological changes associated with tree and shrub encroachment into tundra areas at the scales of in situ field monitoring programs and the regional scale of the Western Siberian Plain.

2018年，俄罗斯亚马尔-涅涅茨自治区萨列哈尔德市附近的极地乌拉尔山脉东坡，设立了三个观测站点（ENGAYU、RAI-IZ、LPTEG）。每个站点在约1000米范围内布设4至5个样地，沿明确的植被梯度覆盖三类生境：高大茂密植被覆盖区（森林，FOREST）、高大稀疏植被区（疏林，TREES）以及以莎草、苔藓和矮灌木为优势种的低矮植被区（苔原，TUNDRA）。在每个样地均架设气象塔，并配套安装了地表及地下测量设备。本数据集的采集工作于2018年至2021年持续开展，采样间隔为30至60分钟。所有数据均经过质量保证与数据管理规程处理，并被整理为三类数据集：(i) 地表与地下综合观测数据（包含降水、气温、相对湿度、风速、四通道辐射通量、净辐射、反照率、土壤热通量）；(ii) 地下专项观测数据（包含五层深度可达100厘米的土壤温度与含水量、上层有机层温度）；(iii) 雪深测量数据。本数据采集工作为美国国家科学基金会（National Science Foundation, NSF）极地项目办公室（Office of Polar Programs, OPP）资助项目的组成部分。该项目的特定目标为，在原位野外监测尺度与西西伯利亚平原区域尺度下，探究与树木及灌木入侵苔原区域相关的生态水文变化。