中文摘要：

依据苹果属最新的分类学研究成果，重新鉴定了中国科学院植物研究所等标本馆的山荆子标本，选取了358个有价值的分布记录转换成地理坐标数据，用DIVA—GIS绘制了现状地理分布，这种分布式样主要呈东北一西南方向延伸，西北一东南方向延伸较小，西南、中部、东北地区变种数量相当。利用全球气候栅格数据（分辨率arc 30s），对落在世界气候变量包络内的分布点的19个气候变鼍进行了主成分分析，发现年降雨量、日均温差／年温差、暖季雨量是山荆子分布的主导因子，变种间的主导因子生态位有一定间隔或仅离群者重叠。用当前气候数据和未来气候数据对山荆子的当前、未来可能潜在分布进行了预测，结果碌示：现状潜在分布区的一些高适区向东南方向迁移，未来气候下潜在分布向北迁移，而最北部的一些分布点消失，分布范围减小。

英文摘要：

Specimens of Malus baccata from some herbaria including the Institute of Botany, Chinese Academy of Sciences Herbarium （PE） were re-identified in light of the latest taxonomic outcome of the genus Malus Mill. and 358 valuable distribution records were selected and digitized into the geographic coordinate data. Based on these data, the updated geographic distribution is mapped using DIVA-GIS. This distribution presents a pattern extending mainly from the northeast to southwest, and secondarily from northwest to southeast. There are almost equal numbers of varieties in the southwest, central and northeast regions. Nineteen climate variables of the distribution points that fall in the envelope of variables of the world climate （spatial resolution arc 30 s） were analyzed by principal component analysis. Annual precipitation, isothermality, precipitation of the warmest quarter were found to be dominant factors affecting the geographic distribution of M. baccata; moreover, there are certain niche intervals of the dominant factors among the varieties, and niche overlaps only to some outliers. The present and future potential distribution maps are predicted by BIOCLIM with current and future climate conditions that are the world climate （spatial resolution arc 30 s）. The results show that some highly suitable areas of the present potential distribution migrate southeastward, the whole future potential distribution extends northward, and some most northerly distribution points disappear; the overall range of distribution reduces.