THE EFFECTS OF GLOBAL WARMING AND CLIMATE CHANGE ON HAZELNUT PRODUCTION, NUMBER OF FRUITING TREES AND YIELD VALUES IN TURKIYE (PANEL DATA ANALYSIS)

In the modern world, the uncontrolled exploitation of natural resources driven by humankind’s pursuit of greater dominance over nature and convenience has exacerbated the climate change process that began with the Industrial Revolution. This phenomenon has reached critical levels today. In recent years, the risk and uncertainty caused by climatic events experienced almost throughout the earth's crust due to global warming have started to affect agricultural products and ecosystems more than ever. Each ecological zone experiences these changes to different extents. Notably, in regions characterized by species-specific climatic traits and dominated by monoculture, the effects of these transformations are more pronounced. In this context, examining the impacts of climate change on hazelnut agriculture in Turkey’s Black Sea Territory, where hazelnut farming is prevalent, and analyzing the outcomes are of great importance. Thisstudy aimed to examine the effects of climate variables measured monthly between 2004 and 2022 on hazelnut yield, tree count, and productivity across leading hazelnut-producing provinces of Ordu, Samsun, Sakarya, Giresun, Düzce, Trabzon, Zonguldak, Artvin, Kocaeli, Bartın, Bolu, and Rize, including all districts within these provinces, through econometric modeling. To assess current climatic conditions, meteorological station data recorded on minimum, average, and maximum temperatures, precipitation, humidity, and wind were analyzed. These twelve provinces were utilized as the scale of analysis for hazelnut cultivation. The model included a cross-sectional application, where provinces served as individual units, and a time series covering 19 years from 2004 to 2022 was used. The model incorporated hazelnut production volume, the number of fruit-bearing trees, and yield values as dependent variables, while atmospheric pressure, relative humidity, wind, temperature, and precipitation were considered independent variables. Based on the findings obtained in the study, regression models with fixed and random effects (Model-1, Model-2, and Model-3) revealed that atmospheric pressure, relative humidity, temperature, and precipitation variables did not independently have significant effects on hazelnut production volume, the number of productive hazelnut trees, or hazelnut yield.