The spatial distribution patterns of rainfall use efficiency (RUE) of evergreen coniferous forests in Chinese subtropical zone

Abstract

Rainfall use efficiency (RUE) of subtropics evergreen coniferous forests and RUE spatial patterns in Chinese subtropical zone were estimated. RUE and ecosystem net primary productivity (NPP) spatial distribution, as well as the relationship between RUE and rainfall were particularly focused. RUE of subtropical evergreen coniferous forests and the spatial patterns were estimated based on the data collected from the related weather stations and peer-reviewed literatures. In our study, a gradually increasing tendency of NPP from northwestern to southeastern part of the subtropical zone is observed. No significant differences in RUE among these tree species are visible. RUE of the evergreen coniferous forests reduces as the rainfall increases. RUE reaches the peak when rainfall is less than 700 mm. However, the distribution of RUE is not evident. In linear regression, longitude, latitude, and PAR account for approximately 1.4% of the variability in RUE. These findings suggest that the RUE of evergreen coniferous forests in southern China has a functional convergence.