Daly Pasture Flux Data Release 2023_v2

This release consists of flux tower measurements of the exchange of energy and mass between the surface and the atmospheric boundary-layer using eddy covariance techniques. Data were processed using PyFluxPro (v3.4.15) as described by Isaac et al. (2017). PyFluxPro produces a final, gap-filled product with Net Ecosystem Exchange (NEE) partitioned into Gross Primary Productivity (GPP) and Ecosystem Respiration (ER).

The site was identified as tropical pasture dominated by species Chamaecrista rotundifolia (round-leaf cassia cv. Wynn), Digitaria milijiana (Jarra grass) and Aristida sp. standing at approximately 0.3  m tall. The soil at the site was a mixture of red kandosol and deep sand. Elevation of the site was close to 70  m and mean annual precipitation at a nearby Bureau of Meteorology site was 1250  mm. Maximum temperatures ranged from 37.5°C (in October) to 31.2°C (in June), while minimum temperatures ranged from 12.6°C (in July) to 23.8°C (in January). Maximum temperatures varied on a seasonal basis between 6.3°C while minimum temperatures varied by 11.2°C. The instrument mast was 15 meters tall. Heat, water vapour and carbon dioxide measurements were taken using the open-path eddy flux technique. Temperature, humidity, wind speed, wind direction, rainfall, incoming and reflected shortwave radiation and net radiation were measured. Ancillary measurements taken at the site included LAI, leaf-scale physiological properties (gas exchange, leaf isotope ratios, N and chlorophyll concentrations), vegetation optical properties and soil physical properties. Airborne based remote sensing (Lidar and hyperspectral measurements) was carried out across the transect in September 2008. The site was destroyed by fire in September 2013.

本数据集包含采用涡度协方差技术（eddy covariance techniques）获取的地表与大气边界层之间能量与物质交换的通量塔观测数据。数据处理采用PyFluxPro（v3.4.15）软件，处理流程参照Isaac等人2017年的研究方法。PyFluxPro可生成最终的间隙填充数据集，将净生态系统交换量（Net Ecosystem Exchange, NEE）划分为总初级生产力（Gross Primary Productivity, GPP）与生态系统呼吸（Ecosystem Respiration, ER）两部分。

该样地为热带牧场，优势物种包括圆叶决明栽培品种Wynn（Chamaecrista rotundifolia cv. Wynn）、贾拉草（Digitaria milijiana）以及三芒草属（Aristida sp.），群落高度约0.3米。样地土壤为红 kandosol与深砂质土的混合体。样地海拔接近70米，邻近的澳大利亚气象局（Bureau of Meteorology）站点记录的年平均降水量为1250毫米。最高气温介于37.5℃（10月）至31.2℃（6月）之间，最低气温则介于12.6℃（7月）至23.8℃（1月）之间。最高气温的季节变幅为6.3℃，最低气温的季节变幅则为11.2℃。

观测塔架高15米。采用开路式涡度通量技术（open-path eddy flux technique）测定热通量、水汽通量与二氧化碳通量。同步观测了气温、相对湿度、风速、风向、降雨量、入射与反射短波辐射以及净辐射。

样地的辅助观测内容包括叶面积指数（Leaf Area Index, LAI）、叶片尺度生理特性（涵盖气体交换、叶片同位素比值、氮素与叶绿素浓度）、植被光学特性以及土壤物理特性。2008年9月，研究团队沿样带开展了机载遥感观测，涵盖激光雷达（Lidar）与高光谱测量。该样地于2013年9月因火灾损毁。