Forest vulnerability to extreme dryness stress - Chapter 5: The impact of compound drought-heatwave event on a mixed deciduous forest in Switzerland: comparisons from compound drought-heatwave events in 2015, 2018 and 2022

Site: Lägeren (CH-LAE, canton Aargau, Switzerland) Managed mixed deciduous mountain forest located on the steep Lägeren mountain (NW of Zurich, Swiss Plateau). The forest is highly diverse, dominated by beech and fir. The site is part of the international CarboEurope IP network and the NABEL (Swiss air quality network) and a long-term forest ecosystem research site (LWF) of the WSL (Institut f. Wald Schnee & Landschaft).;
Longitude (WGS 84): 8°21'51.8" E;
Latitude (WGS 84): 47°28'42.0" N
Altitude (m.a.s.l): 682;
Land cover (IGBP land classification): Mixed Forest;
Soil type: The main soil types are rendzic leptosols (or rendzinas) and haplic cambisols according to the World Reference Base of Soil Resources (IUSS Working Group WRB, 2007). The litter layer is thin, since leaf litter decomposes almost completely within one year.;
Geology: The main bedrocks of the study site are limestone, marl and sandstone, with transition zones between marl and limestone (loamy debris) and marl mixed with sandstone (loam).

研究站点：莱格伦（Lägeren，CH-LAE，瑞士阿尔高州），该站点位于苏黎世西北侧瑞士高原区域的陡峭莱格伦山地，为经营型混合落叶山地森林。该森林物种多样性极高，以山毛榉和冷杉为优势树种。本站点隶属于国际碳欧洲倡议项目（CarboEurope IP）、瑞士空气质量网络（NABEL），同时也是瑞士联邦森林、雪与景观研究所（WSL，原德文名称：Institut f. Wald Schnee & Landschaft）下属的长期森林生态系统研究站点（LWF）；
经度（世界大地测量系统1984（WGS 84））：8°21'51.8" E；
纬度（世界大地测量系统1984（WGS 84））：47°28'42.0" N
海拔（米，海拔基准面为海平面（m.a.s.l.））：682；
土地覆盖类型（国际地圈生物圈计划（IGBP）土地分类标准）：混合森林；
土壤类型：依据国际土壤科学联合会（IUSS）世界土壤资源参比基础（WRB）工作组（2007）的分类标准，研究区主要土壤类型为钙质粗骨土（rendzic leptosols，亦称rendzinas）和普通雏形土（haplic cambisols）。由于叶片凋落物几乎可在一年内完全分解，故腐殖质层较薄；
地质条件：研究区主要基岩为石灰岩、泥灰岩与砂岩，其中泥灰岩与石灰岩之间存在过渡带（壤质碎屑），泥灰岩与砂岩混合区域则发育壤质土壤。