Impacts of Climate Change on Hazelnut (Corylus avellane L.) Cultivation in Bhutan

This study was conducted to evaluate the factors contributing to the spatial distribution of European hazelnut (Corylus avellane L.) in Bhutan and determine the suitable areas for cultivation of the crop in the near future (2040-2060) and distant future (2060-2080) under different climate scenarios of Representative Concentration Pathway (RCP)  2.6 and RCP 4.5 in Bhutan. The environmental layers were obtained from WorldClim and processed in ArcGIS and R software prior to running the model in MaxENT. The multicollinearity test showed six bioclimatic factors and three topographical factors contributing to the distribution of European hazelnut in Bhutan. The findings indicated that approximately 10,744.8 sq. km is potential for hazelnut crop cultivation in Bhutan, with Wangduephodrang District harboring the highest area of 1,227.9 sq. km (11.4%) and Gasa district the least at 130 sq. km. The primary factors affecting climate suitability of European hazelnut were elevation, contributing 87.9%, followed by Bio3 (3.7%), BIO2 (3%), and Bio1 (2.5%), and the least factors were Bio15 and aspect at 0.1% each. The model showed that the most suitable elevation for the growth of hazelnut ranges from 1500-1900 masl. The suitability area for the crop projected under the RCP 2.6 and RCP 4.5 scenarios showed a decline in the near future (2040-2060) in the southern part of the country and a slight increase in the distant future (2061-2080) in Central, Eastern, and Western Bhutan. Therefore, there is an urgent need for climate risk assessment, community-based mitigation measures, and spatial monitoring techniques on agriculture crops in Bhutan.