TREELINE - Longterm atmospheric and pedo-climatic observations along an upper treeline ecotone in the Himalayas, Nepal

• Main Authors: Weidinger, Johannes, Gerlitz, Lars, Bobrowski, Maria, Böhner, Jürgen, Chaudhary, Ram Prasad, Schickhoff, Udo, Schwab, Niels, Scholten, Thomas
• Format: Dataset
• Language: English
• Published: Universität Hamburg 2021
• Subjects: TREELINE Project; soil and atmosphere; wind speed; wind direction; air temperature; relative humidity; precipitation; radiation data; automatic weather stations; soil moisture; soil temperature; treeline; meteorological observations; monsoon; Rolwaling Himal; Himalayas; Nepal; Gaurishankar Conservation Area; remote sensing; Tundra
• Online Access: https://dx.doi.org/10.25592/uhhfdm.9562; https://www.fdr.uni-hamburg.de/record/9562

This data set includes meteorological and pedo-climatic data obtained from a study area in central Himalayas, Nepal. The study area is located in the Rolwaling valley along the Rolwaling Himal in the Gaurishankar Conservation Area (GCA) in the Dolakha district. In this region the upper treeline ecotone is located in a subtropical high-altitude alpine forest zone with strong differences in land cover on opposing valley slopes. South-facing slopes are traditionally highly shaped by anthropogenic practice and dominant tree species forming the treeline are Juniperus spp. On north-facing slopes dense forests are consisting primarily of Betula utilis and Abies spectabilis with Rhododendron campanulatum , Sorbus microphylla , Acer caudatum and Prunus rufa communities. On the upper end of the main study site the forests are locked with a wide Rhododendron campanulatum krummholz belt which is followed by Rhododendron spp. dwarf shrubs and alpine tundra in higher areas. Within the east-west extending valley eight automatic weather stations (AWS) were installed since April 2013. These were mounted on different slopes and positions stretching from around 3700m up to over 5000m a.s.l. In 2m above surface (sensor type in brackets) incoming solar radiation [Wm - ²] (ONS-S-LIB-M003), air temperature [°C] (ONS-S-THB-M002) and relative humidity [%] (ONS-S-THB-M002), wind speed [ms -1 ] (ONS-S-WSB-M003) and wind direction [°] (ONS-S-WDA-M003) as well as precipitation [mm] (ONS-S-RGB-M002) are measured every 3min and logged every 15min. Four AWS are positioned in the main study site in the valley representing two altitudinal transects along different slope expositions in north-western and north-eastern directions. Additionally 34 pedo-climatic Koubachi combined soil temperature [°C] and soil moisture [pF] loggers were installed from April 2013 until September 2015 in four different altitudinal belts along the transects in 10cm depth. These also follow the aforementioned pattern with different expositions and both parameters were logged in hourly intervals. Data quality: Winter precipitation is underestimated due to non-heated rain gauges. During the project start several vandalism incidents resulted in data loss and gaps in the time series. For hydrological modelling temperature and precipitation data sets are available in a gap filled version. Atmospheric sensors of AWS: 2m above surface: incoming solar radiation [Wm - ²]; air temperature [°C]; relative humidity [%]; wind speed [ms -1 ]; wind direction [°]; precipitation [mm]; measuring interval: 3min; logging interval: 15min. Locations of automated weather stations (ONSET) Station; Longitude [°E]; Latitude [°N]; Altitude [m.a.s.l.]; Instal. Date; NW bottom; 86.3762; 27.9009;3718.9; 2013-04-18; NW top; 86.3742; 27.8967; 4035.9; 2013-04-15; NE bottom; 86.3791; 27.8986; 3734.2; 2013-04-18; NE bottom; 86.3791; 27.8986; 3734.2; 2013-04-18; NE top; 86.3759; 27.8934; 4158.3; 2013-10-17; Beding Gompa; 86.3755; 27.9050; 3886.0; 2013-04-19; Na; 86.4337; 27.8782; 4192.1; 2013-04-21; Dudgunda; 86.4604; 27.8756; 4532.2; 2016-09-29; Yalun; 86.4338; 27.8590; 5005.2; 2013-10-20; Pedo-climatic sensors of Koubachis: 10cm sensor soil depth; soil temperature [°C]; soil moisture [pF]; measuring and logging interval: 60min. Locations of pedo-climatic loggers (Koubachi AG) Belt / Logger groups; Altitudinal range [m a.s.l]; Altitudinal zone; Number of functional loggers (in 06/2015) NE-2 A; 3750 - 3900 m; closed forest; 4 (100%); NE-2 B; 3900 - 4000 m; uppermost closed forest; 2 (50%); NE-2 C; 4000 - 4100 m; krummholz belt; 4 (100%); NE-2 D; 4100 - 4250 m; dwarf scrub heath / alpine tundra; 3 (75%); NW-1 A; 3750 - 3800 m; closed forest; 3 (75%); NW-1 B; 3800 - 3900 m; uppermost closed forest; 3 (75%); NW-1 C; 3900 - 4050 m; krummholz belt; 3 (75%); NW-1 D; 4100 - 4250 m; dwarf scrub heath / alpine tundra; 3 (75%); NE-2 sp; 4000 - 4050 m; Abies spectabilis / Betula utilis individuals; 2 (100%); All data is stored as .csv files in UTF-8 encoding.