Bioclimatic factors affecting the distribution of Quercus robur L. (pedunculate oak) subspecies in Turkey

Abstract

Understanding the distribution of individual species and the factors affecting their distribution is a key issue in biogeography, ecology and conservation. This study was carried out to determine bioclimatic factors affecting the two pedunculate oak subspecies (Quercus robur L. subsp. robur and Q. robur subsp. pedunculiflora (K.Koch) Menitsky) of Turkey and their tolerances to these factors. Mean Temperature of Coldest Quarter (Bio 11), Temperature of Coldest Month (Bio 6), Temperature Annual Range (Bio 7), Temperature Seasonality (Bio), Precipitation Seasonality (Bio 15), Isothermality (Bio 3), Annual Mean Temperature (Bio1) are highly correlated bioclimatic variables that effect the distribution of pedunculate oak subspecies. Multinominal logistic regression result showed that the Bio4 is the only descriptor of the current distribution of subspecies robur and subspecies pedunculiflora. The results also indicate that subspecies pedunculiflora shows a greater tolerance for extreme variation such as more drought summer and colder winters extreme variations during hot summers whereas subspecies robur is more sensitive to these climate variables.