Compiled soil N2O emission data from Eastern China forests

We searched the Thomson Reuters Web of Science Core Collection and China National Knowledge Infrastructure (CNKI) theses database for literature published before January 1, 2020, using the terms “forest” AND “greenhouse gas” OR “N2O” OR “nitrous oxide” in the titles, abstracts, and keywords; this returned 5,948 records and 590 records, respectively. Considering the different preferences for terminology (e.g., nutrient addition, simulated N deposition), we refined our search manually. The criteria for our refinement were as follows: (a) N addition experiment was conducted in eastern China forests with detailed records of N addition levels; (b) N2O flux was observed using the static chamber method so that data from different sites were comparable. A total of 58 papers from 38 research sites met our criteria. 

We also collected the data of soil N2O emission rates under natural conditions. The data were collected from literature that met the following criteria: (a) N2O fluxes were observed in eastern China forests using the static chamber method; (b) no manipulated experiments were conducted, and no nitrogen was added except for natural N deposition. There were 42 papers and theses that met these criteria, covering 30 different sites. 

From the abovementioned papers and theses, the soil N2O emission rates and the auxiliary information (coordinates, ecoregion type, natural N deposition rate, multi-year mean annual temperature, multi-year mean annual precipitation, and soil texture) were compiled (ds01).

To obtain the soil N2O emission rates of Eastern China forests on grid level (10km × 10km), another dataset (ds02) on the environmental factors (ecoregion type, natural N deposition rate, multi-year mean annual temperature, multi-year mean annual precipitation, and soil texture) of each grid was compiled from the spatial datasets, including the Chinese vegetation ecoregion map from the Resources, Environmental Sciences, and Data Center at the Chinese Academy of Sciences (https://www.resdc.cn/data.aspx?DATAID=133), as well as the soil texture raster data (https://www.resdc.cn/data.aspx?DATAID=260), mean annual temperature raster data (1995–2015; https://www.resdc.cn/data.aspx?DATAID=228), and mean annual precipitation raster data (1995–2015; https://www.resdc.cn/data.aspx?DATAID=229). Land use and land cover raster data (2000–2015) were obtained from the Project on Big Earth Data Science Engineering (https://data.casearth.cn/sdo/detail/5c19a5650600cf2a3c557aae). Finally, annual N deposition rate and multi-year mean N deposition (MAN) data were derived from a N deposition dataset from mainland China previously constructed by our group.