Cumulative precipitation imposed in the Jena-Ecotron experiment

This dataset contains cumulative precipitation imposed in the Jena-Ecotron Experiment in 2012. This experiment was conducted in the Montpellier European Ecotron (CNRS, France), an advanced controlled environment facility for ecosystem research, and aimed at understanding the impact of plant species richness (4 vs. 16 species) for ecosystem carbon and water fluxes.
The soil monoliths used in this experiment contained plant communities originating from the long- term Jena Experiment (50°57.1' N, 11°37.5' E, 130 m above sea level; mean annual temperature 9.3°C, mean annual precipitation 587 mm) established in May 2002. Twelve plots were selected for the Jena-Ecotron study according to the following criteria: (1) the four functional groups grasses, legumes, small and tall herbs were present, (2) realized species numbers were close to sown species richness, and (3) plots were equally distributed across the experimental field site to account for different soil textures. Large monoliths (2 m² surface area, diameter of 1.6 m, 2 m depth with a weight of 7 to 8 tons) including intact soil and vegetation were excavated in December 2011 and placed in lysimeters. In March 2012, before the start of the vegetation growth, the lysimeters were transported and installed in the Macrocosms platform of the Montpellier European Ecotron.
The precipitation imposed in the Jena-Ecotron experiment aimed at reconstructing the field-measured values recorded in Jena in year 2007. This year was chosen as a proxy of average climatic conditions at the Jena field site. Note that owing to the higher evapotranspiration rates in the Ecotron, higher precipitation (+28%) was imposed in the Ecotron relative to year 2007. Precipitation was applied to each lysimeter by manual watering using a hose equipped with a sprinkler and a flowmeter. The water was purified by microfiltration (1µ) and reverse osmosis followed by ozone and UV treatments.
Precipitation values are provided as cumulative values from 28th of March 2012 to 30th of July 2012.

本数据集包含2012年耶拿生态箱实验（Jena-Ecotron Experiment）中施加的累积降水量。该实验于法国国家科学研究中心（CNRS）下属的蒙彼利埃欧洲生态箱开展，这是一座用于生态系统研究的先进受控环境设施，旨在探究植物物种丰富度（4种与16种对比）对生态系统碳、水通量的影响。

本实验所用的土壤原状柱（soil monoliths），其植物群落源自2002年5月建立的长期耶拿实验场地（北纬50°57.1'，东经11°37.5'，海拔130米；年平均气温9.3℃，年平均降水量587毫米）。本次耶拿生态箱研究按照以下标准选取了12个样地：（1）包含禾本科、豆科、小型草本与高大草本四大功能群；（2）实际物种数量与播种设定的物种丰富度相近；（3）样地在实验场地内均匀分布，以覆盖不同的土壤质地类型。2011年12月，研究人员挖掘了包含完整土壤与植被的大型原状柱（表面积2平方米，直径1.6米，深度2米，重量7至8吨），并将其安置于渗漏计（lysimeters）中。2012年3月，在植被生长季开始前，这些渗漏计被运至蒙彼利埃欧洲生态箱的大型模拟生态系统（Macrocosms）平台并完成安装。

耶拿生态箱实验中施加的降水量，旨在还原2007年在耶拿场地实测的降水数据。之所以选择2007年，是将其作为耶拿实验场地平均气候条件的参照。需注意的是，由于生态箱内的蒸散发（evapotranspiration）速率更高，因此相较于2007年，本次实验施加的降水量提升了28%。降水施加采用配备洒水器与流量计的软管通过人工浇灌的方式，对每个渗漏计进行供水。所用水源经过微滤（1µ）、反渗透，随后辅以臭氧与紫外处理完成净化。

本数据集提供的降水量数据为2012年3月28日至2012年7月30日的累积降水量。