Identification of soils factors influence in the distributions of Tuber aestivum in Transylvanian Subcarpathian Hill, Romania

Abstract

Truffles are one of the most hunted varieties of mushrooms in Europe due to their high price and their increasingly frequent use in the kitchen. As demonstrated by several studies, soil conditions are among the main factors that influence the spread and development of the black truffle species. The purpose of this study was to identify the soil factors which directly and indirectly influence the distribution of black truffles (Tuber aestivum Vittad.) in Romania and to identify the areas from the Subcarpathian Hills of Transylvania which are highly favourable to their existence and growth, using G.I.S. spatial analysis and databases which include soil characteristics (soil type, texture, gleization, stagno-gleization) and territorial localisation through GPS points indicating the samples of Tuber aestivum. By implementing the statistical model of spatial analysis (BSA - Bivariate Statistical Analysis) for each characteristic, a series of areas were classified into three classes of favourability (low, medium, high) for the growth of Tuber aestivum. The results were validated indirectly by comparing the overlapping of the areas from the high favourability class with the areas covered with tree species from the Quercus genus and directly, through field research (on the surfaces with maximum favourability), done by specialised truffle seekers. The results were validated with a very high confidence rate for both methods (method 1 - overlapping of approximatively 93%, method 2 - Tuber aestivum was identified on 12 out of 15 test surfaces from the high favourability class).