Understorey plant community and associated environmental variables during the period September 2012 and February 2016 at EucFACE

This package contains the base datasets used in the paper–entitled “Elevated CO2 concentrations reduce C4 cover and decrease diversity of understorey plant community in a Eucalyptus woodland”– in press at Journal of Ecology (accepted on 26th January 2018). The effects of elevated CO2 concentrations on understorey vegetation was studies at the Eucalyptus Free-Air CO2 Enrichment (EucFACE) experiment. Understorey species cover was determined in four, randomly located permanent 2 x 2 m plots in each of the six rings. Presence/absence of all species was surveyed in each of one hundred 20 x 20 cm cells per plot. The first survey was conducted in September 2012, and all but graminoid species were identified. Graminoid species identifications were confirmed in December 2012, when most were in flower. Subsequent surveys were conducted in the same plots in summer (January 2014, January 2015 and February 2016) and identified all understorey species at these times. In addition to raw data of forb and graminoid cover, ring means of environmental variables for each survey year (soil moisture, understorey temperature and photosynthetic radiation, and soil availability of nitrate, ammonium and phosphate) are included.

本数据包包含论文《升高的CO₂浓度降低桉树疏林林下植物群落的C4植物覆盖度及多样性》所用的基础数据集，该论文已被《生态学杂志》（Journal of Ecology）接收并即将发表（接收日期：2018年1月26日）。在桉树自由空气CO₂富集（EucFACE）实验中，研究了升高的CO₂浓度对林下植被的影响。林下物种覆盖度在六个环中每个环内随机设置的四个2×2米永久样方中测定；每个样方内的100个20×20厘米小样方中调查了所有物种的存在/缺失情况。首次调查于2012年9月开展，除类禾本科植物（graminoid species）外，其余物种均完成识别；类禾本科植物的物种鉴定结果于2012年12月（多数物种处于花期时）得到确认。后续调查于夏季（2014年1月、2015年1月及2016年2月）在相同样方中进行，识别了各时间点的所有林下物种。除非禾本科草本植物（forb）和类禾本科植物覆盖度的原始数据外，数据包还包含各调查年份每个环的环境变量均值，包括土壤湿度、林下温度、光合辐射，以及土壤中硝酸盐、铵盐和磷酸盐的有效性。