Divergent Ecological Restoration Driven by Afforestation Along the North and South Banks of the Yarlung Zangbo Middle Reach

ABSTRACT Over the past four decades, continuous afforestation in the river valley of the Yarlung Zangbo Middle Reach has effectively migrated the land degradation and enhanced the local eco‐environment. Different orientations of north and south banks (i.e., sun‐facing and shade‐facing) generate microclimates, but the diverse growth patterns of the planted forests along different banks remain unknown. In this study, long‐term Landsat observations were introduced to investigate the microclimatic effects on the growth patterns of planted forests and their subsequent effects on the land restoration during 1988–2020. Results showed that the south bank experienced a higher afforestation‐induced greening trend than the north bank, as indicated by normalized difference vegetation index (NDVI) rates of 0.0117 and 0.0081 year −1 , respectively. The growth of planted forests on the north bank was more sensitive to the distance from riverway than that on the south bank, with the NDVI gradients of −0.0708 and −0.0540 km −1 , highlighting a server drought stress on the north bank. Benefited from the continuous afforestation, 79% and 95% of sandy lands on the north and south banks had been restored by 2020. In summary, the microclimatic difference between banks, attributed to different solar illuminations and drought stresses, induce the diverse ecological restoration conditions. These findings offer important insights that future afforestation strategies should consider the microclimatic effect to maximize ecological benefits.