Warm Index and Growing Degree Days as Indicators of Climate Changes for Growth of Quercus Eagilops and Pistacia Khinjuk Trees in the Dohuk Region

This study investigates the impact of climate change on the growth and vitality of vegetation, specifically focusing on two tree species, Pistacia khinjuk and Quercus aegilops, in dry and semi-dry sites (Dohuk-Sarsink). Climate-induced temperature increases have exceeded the trees' tolerance, leading to physiological changes and reduced productivity. The research aims to assess growth decline and environmental factor changes, using random samples to measure tree morphology (diameter, height, and crown dimensions). The Warm Index (WI) and Growing Degree Days (GDD) were estimated for both sites, revealing suboptimal temperature conditions for tree growth. The results show that current temperatures significantly hinder growth, emphasizing the need for climate-adaptive strategies to support tree development in these regions.