Abstract
Vegetation reduction could affect regional climate by perturbing the surface energy and moisture balances via changes in albedo and evapotranspiration. However, it is unknown whether vegetation effects on climate occur in North Korea, where a severe reduction in forest cover has been observed. This study aimed to identify the biogeophysical processes in vegetation and climate interactions in North Korea, using Normalized Difference Vegetation Index (NDVI) and climate reanalysis data over the period 1982‒2015. As per the NDVI regression trend results, the highest rates of decreasing NDVI were detected in the western region of North Korea during summer. Based on the detrended correlation analysis of NDVI with surface energy variables at each grid point, including solar radiation, sensible and latent heat fluxes, Bowen ratio, and temperature, we identified a cooling effect of vegetation in the western region (with lower NDVI and lower elevation), but a warming effect of vegetation in the northern region (with higher NDVI and higher elevation). The different biogeophysical effects were induced by the increasing and decreasing Bowen ratio with increasing vegetation in the northern and western regions, respectively. In the western region of North Korea, where large-scale human-induced forest loss has been observed, the increasing summer temperature caused by the decreasing cooling effect of vegetation would be up to 1.5 ℃ by the end of this century, if the current rate of deforestation continues. Thus, we urgently suggest that sustainable management and restoration of forests are needed in North Korea, which is among the countries most vulnerable to climate change now and in the future.