ObjectiveSorbus alnifolia, an excellent forest germplasm resources, has significant ecological and ornamental values. An overall understanding of its natural distribution status and ecological characteristics in China will contribute to develop the resource conservation and scientific introduction planning for this species.

MethodBased on the data from 183 field collection and historical sample documents, we applied DIVA-DIS software of geographic information technology and combined with BIOCLIM model to analyse the distribution pattern of S. alnifolia and its dominant climate factors qualitatively and quantitatively for the first time.

ResultThe current potential distribution areas of S. alnifolia cover the provinces of Chinese eastern monsoon region, and the evaluation based on results of BIOCLIM Modeling combined with Simpson's diversity index showed that the mountainous regions of central China, coastal hilly area of northern China and northeastern China were its three most concentrated areas. Among them, border of mountainous regions projected from provinces of Shaanxi, Henan, Hubei and Chongqing and their junctions (Qinling-Daba-Wushan mountain ranges) can be regarded as its core distributing areas. Principal component analysis (PCA) of climatic variables and the dominant climate factor contributing rates were in sequence of annual mean precipitation (bio12) > precipitation in the wettest season (bio16) > seasonally varied SD of temperature (bio4) > precipitation in the warmest season (bio18) > precipitation in the coldest season (bio19). The cumulative frequency curves further confirmed that the ecological characteristics of geographical distributing area for S. alnifolia were 423.00-1 508.00 mm, 245.00-675.00 mm, 590.63-1 280.93 (SD×100), 229.00-655.00 mm and 8.00-185.00 mm, respectively. The receiver operating characteristic curve (ROC) and Kappa statistics for model assessment reached 0.782 and 0.515, respectively, meeting the general demands for prediction accuracy.

ConclusionThe above research indicated that the current distributing pattern of S. alnifolia was mainly affected by precipitation factors driven by the eastern Asian monsoon at regional scale, also with preference of moderately low temperature and high altitude environment. What's more, differences in distributing patterns of S. alnifolia were also affected by geographical factors, including altitude, latitude and longitude to some extent.