Impacts of juniper woody plant encroachment into grasslands on local climate

Woody plant encroachment (WPE) into grasslands has been exacerbated by climate change and human activities. WPE may affect local climate by altering the exchange of mass and energy between the land surface and the atmosphere. The lack of studies on the effects of WPE on local climate hinders our understanding of the interactions between changes in regional vegetation cover and climate. Here, we analyzed the differences of land surface temperature (Delta LST), albedo (Delta Albedo) and evapotranspiration (Delta ET) between juniper-woody-encroached grasslands and adjacent pure grasslands using 16-years of remote sensing data. Our results showed that juniper woody plant encroachment (JWPE) into the semi-arid and sub-humid grasslands reduced daytime LST and albedo, but increased nighttime LST and ET from an annual scale analysis. With each one percent increase in juniper cover, annual mean daytime Delta LST decreased similar to 0.026 degrees C, nighttime Delta LST increased similar to 0.01 degrees C, daily Delta LST decreased similar to 0.008 degrees C, Delta albedo decreased similar to 0.053%, and Delta ET increased similar to 1.31 mm/year. Furthermore, it is suggested that the impacts of JWPE on LST and ET were stronger in dry years than in normal and pluvial years, and that no significant variations in albedo were found among the different hydrological conditions. These results provide insights into applying satellite-based techniques to understand the feedbacks between woody vegetation dynamics and local climate change.

Automated summary

The study analyzed the impact of woody plant encroachment (WPE) on land surface temperature, albedo, and evapotranspiration, finding that WPE leads to a decrease in daytime land surface temperature and albedo, while increasing nighttime land surface temperature and evapotranspiration.