Nutrient Dynamics in Oak Forests of Iraqi Kurdistan due to Altitudinal and Geospatial Influences

Abstract
Oak forest nutrient dynamics are mainly affected by altitudinal and geospatial differences. This creates a great difference in soil nutrient availability and uptake by the trees, which have a significant consideration in forest management. The study examined the variability in soil and leaf nutrient contents (nitrogen, phosphorus, potassium, and calcium) in Quercus aegilops and Quercus infectoria at eleven selected oak forests in the Iraqi-Kurdistan region. Clustering of soil characteristics and altitudinal-geospatial data in principal component analysis (PCA) showed a strong correlation between variables such as CaCO₃, organic matter (OM), N, P, and altitude. A strong correlation between electrical conductivity (EC) and K and latitude and altitude was highlighted. The nitrogen content was 2.91%, recorded as the highest value in leaves of Q. infectoria leaves at Talwa. Conversely, the lowest value (1.04%) was observed in Q. aegilops leaves at Shaqlawa. Phosphorus content variation was significantly recorded, with the highest content of leaves (0.69%) recorded in Q. aegilops leaves at Qaradakh and the lowest value (0.33%) in Q. infectoria leaves at Barzan. Significant variation in potassium content was observed; the highest value was 1.953% in Q. infectoria leaves at Barzan. The minimum content was 1.093% of Q. aegilops at Shaqlawa. Calcium content also showed a significant variation, with the highest level (0.27%) in Q. infectoria leaves at Sarsang compared to a lower level (0.17%) from Shaqlawa. These findings explain the role of topography and climate in nutrient distribution dynamics across the oak forest ecosystems. That could help the forest management strategies, and enhance the sustainability and afforestation of oak forests in Iraqi Kurdistan region.