The temporal response of soil respiration to environment differed from that on spatial scale

In the context of increasing CO2 concentrations and climate warming, there are large uncertainties regarding the regulatory mechanisms of soil respiration and its accurate assessment. As an area sensitive to global climate change, China covers a broad range of longitudes, latitudes, and altitudes, and it is of great significance to study the spatial and temporal patterns of soil respiration and its environmental response in China's terrestrial eco-systems to clarify the mechanisms of regional and global carbon balance processes. Based on the expanded annual soil respiration dataset from 1993 to 2020, we evaluated soil respiration in China's terrestrial ecosystems and its responses to environmental factors. The mean annual soil respiration in China's terrestrial ecosystems was 777.90 +/- 489.43 g C m- 2 yr- 1 by arithmetic averaging and 595.52 g C m- 2 yr- 1 by area weighting, with soil respiration in wetlands being higher than that of the forest, grassland, shrubland, cropland, and desert. Soil respiration showed a significant upward trend from 2000 to 2017, which was mainly caused by a significant increase in soil respiration in grasslands due to increasing precipitation. In addition, we found differences in the environmental factors influencing the interannual and spatial variability of soil respiration. The response sensitivities of soil respiration to environmental changes differed significantly among the various ecosystem types; however, these differences were not significant when comparing interannual and spatial scales. This study provides information on soil respiration in China's terrestrial ecosystem and highlights the importance of considering the two-dimensional responses of soil respiration to environmental changes in both time and space.

Automated summary

This study investigated soil respiration in China's terrestrial ecosystems and its responses to environmental factors, revealing spatial and temporal variations and differences in sensitivity to environmental changes.