Ecological Influences on Tuber Aestivum Distribution in the Subcarpathian Region of Transylvania

The aim of this research was to identify the ecological factors which have influences on distribution, development and habitat suitability of the summer truffle (Tuber aestivum) in the Sub-Carpathian region of Transylvania. The ecological factors such as average annual temperature (°C), average annual precipitation (mm/year), the length of the bioactive period (months), land slope (grade), slope orientation, soil pH and its compaction level were analyzed having specific influences on forest vegetation development in Sub-Carpathian hills, and in the same time on the possibility of symbiosis existence between the trees and summer truffle. The most favorable regions from the Sub-Carpathians of Transylvania for summer truffle growth proved to be Dealurile Năsăudului and Homoroadelor Sub-Carpathians followed by Muscelele Năsăudului and hills of Bistrița, where the average annual temperature is between 6,8-11°C with an average annual precipitation of 900 mm/year, a 3-6 months long bioactive period and high humus content of the soil.