A globally gridded heterotrophic respiration dataset based on field observations

There are two datasets in this data repository: the first one, named “RH.RF.720.360.1980.2016.Yearly.nc”, is a global heterotrophic respiration (RH) product with a spatial resolution of with 0.5 degree and a time resolution of one year. The global RH product is modelled by Random Forest algorithm with field observations and environmental variables. The environmental variables include temperature, precipitation, diurnal temperature range from CRU TS v.4.01 from 1901 to 2016; shortwave radiation; soil organic carbon content from soil grid data (Hengl et al., 2017); soil nitrogen content from ORNL DAAC; nitrogen deposition data from the Earth System Models of GISS-E2-R, CCSM-CAM3.5 and GFDL-AM3 from the 1850s to 2000s; Palmer Drought Severity Index (PDSI); and soil water content.The RH product is provided in network Common Data Form, version 4 (netCDF-4, short name: nc) data format (https://www.unidata.ucar.edu/software/netcdf/). The RH product is named using the following regulation:"RH.modelling approaches.spatial resolution.start YYYY. end YYYY.temporal resolution.nc"“RH.RF.720.360.1980.2016.Yearly.nc” means modelled RH flux (g C m^-2 yr^-1) by Random Forest (RF) with a 0.5° spatial resolution (size 720 along longitude and 360 along latitude) from start year 1980 to end year 2016 with a yearly temporal resolution.The second file, named “dataset.xlsx”, is the field observation from peer review publications combining Global Soil Respiration Database (SRDB), (version 3, Bond-Lamberty and Thomson, 2014), which is publicly available at https://github.com/bpbond/srdb. Besides, the database was further updated using observations collected from the China Knowledge Resource Integrated Database (www.cnki.net) up to March 2018 according to the criteria of SRDB. This dataset is provided in Microsoft Excel in format of “.xlsx”.R codes to produce main results and land area (named land.area.nc, km^2) are available.

本数据集仓库中共包含两套数据集：第一套命名为"RH.RF.720.360.1980.2016.Yearly.nc"，为全球异养呼吸（heterotrophic respiration, RH）产品，其空间分辨率为0.5°，时间分辨率为1年。该全球RH产品基于野外观测数据与环境变量，通过随机森林（Random Forest, RF）算法建模生成。所用环境变量涵盖：1901年至2016年期间CRU TS v.4.01数据集提供的气温、降水与气温日较差；短波辐射；源自土壤网格数据（Hengl等，2017）的土壤有机碳含量；ORNL DAAC提供的土壤氮含量；1850年代至2000年代期间，来自GISS-E2-R、CCSM-CAM3.5与GFDL-AM3地球系统模型的氮沉降数据；帕默尔干旱指数（Palmer Drought Severity Index, PDSI）；以及土壤含水量。该RH产品采用网络通用数据格式第4版（network Common Data Form version 4，netCDF-4，简称nc，https://www.unidata.ucar.edu/software/netcdf/）存储。其命名遵循以下规则："RH.建模方法.空间分辨率.起始年份.结束年份.时间分辨率.nc"。文件名"RH.RF.720.360.1980.2016.Yearly.nc"代表：1980年至2016年期间、时间分辨率为年际、空间分辨率0.5°（经度方向含720个格点，纬度方向含360个格点）、采用随机森林算法建模的RH通量产品，单位为g C m⁻² yr⁻¹。

第二套数据集命名为"dataset.xlsx"，其数据源自同行评议文献中的野外观测结果，整合了全球土壤呼吸数据库（Global Soil Respiration Database, SRDB）第3版（Bond-Lamberty与Thomson，2014），该数据库公开获取地址为https://github.com/bpbond/srdb。此外，研究团队依据SRDB的筛选标准，补充了截至2018年3月从中国知网（China Knowledge Resource Integrated Database, CNKI，www.cnki.net）收录的观测数据，对该数据库进行了更新。该数据集以Microsoft Excel的.xlsx格式存储。

本仓库同时提供用于生成主要研究结果的R代码，以及陆地面积数据（命名为land.area.nc，单位：km²）。

搜集汇总

背景与挑战

背景概述

该数据集包含全球异养呼吸（RH）产品和现场观测数据，RH产品通过随机森林算法结合环境变量建模，具有0.5度的空间分辨率和一年的时间分辨率。数据集还提供了用于分析的R代码和土地面积数据。