北京松山国家级自然保护区野生种子植物分布及物种组成分析

采取踏查、样方和样线相结合的方法，调查了北京松山国家级自然保护区内野生种子植物的分布状况，并对其种类组成和分布区类型进行了分析。调查结果显示：该保护区内共有野生种子植物92科382属721种，其中，裸子植物3科4属5种、被子植物89科378属716种；被子植物中包含双子叶植物78科298属569种和单子叶植物11科80属147种。含20种或20种以上的科有7个，包含的属、种数量均占该保护区野生种子植物属、种总数的40%以上，优势科现象明显；含1种和含2-4种的属分别有235和128个，具有绝对优势。该保护区野生种子植物科的分布区类型可分为8个，除世界广布科外，以泛热带分布型科和北温带分布型科为主；属的分布区类型可分为15个，以北温带分布型属为主，热带性质属与温带性质属的数量比为0.20。该保护区内有国家重点保护野生植物2种、北京市重点保护野生植物52种，其中包含兰科（Orchidaceae）植物14属18种以及数量极少的丁香叶忍冬（LoniceraoblataK.S.HaoexP.S.HsuetH.J.Wang）和北京市特有植物北京水毛茛（BatrachiumpekinenseL.Liou）；该保护区内还有7种具有入侵倾向的外来植物。此外，还有北京新记录植物3种，分别为柳叶野豌豆也Viciavenosa（Willd.exLink）Maxim.页、北方红门兰（OrchisroborowskiiMaxim.）和廻旋扁蕾也Gentianopsiscontorta（Royle）Ma页。研究结果表明：该保护区的野生种子植物区系具有典型的温带性质并有一定的过渡性。

Analyses on distribution and species composition of wild seed plant in Beijing Songshan National Nature Reserve

Distribution status of wild seed plant in Beijing Songshan National Nature Reserve was investigated by means of combination methods of field survey, quadrat and transect, and also, species composition and distribution type were analyzed. Investigation results show that there are wild seed plant of 721 species in 382 genera belonging to 92 families in the reserve, which include gymnosperm of 5 species in 4 genera belonging to 3 families and angiosperm of 716 species in 378 genera belonging to 89 families, and angiosperm includes dicotyledon of 569 species in 298 genera belonging to 78 families and monocotyledon of 147 species in 80 genera belonging to 11 families. There are 7 families containing 20 species or more than 20 species, numbers of genus and species included in these families account for above 40% of total numbers of genus and species in the reserve, with the phenomenon of obvious dominant family. Number of genera of containing 1 species and 2 - 4 species is 235 and 128, respectively, with absolute predominance. Family distribution type of wild seed plant in the reserve can be divided into 8 types, Pantropic and North Temperate families are the majority except for Cosmopolitan family. Genus distribution type can be divided into 15 types, in which North Temperate genus is the majority, and number ratio of tropic genus to temperate genus is 0. 20. There are 2 species of national key protected wild plants and 52 species of Beijing key protected wild plants, which contain 18 species of 14 genera in Orchidaceae, very few Lonicera oblata K. S. Hao ex P. S. Hsu et H. J. Wang and the Beijing endemic species Batrachium pekinense L. Liou. And there are 7 exotic species with invasion tendency in the reserve. In addition, there are 3 new record species of Vicia venosa （Willd. ex Link） Maxim., Orchis roborowskii Maxim. and Gentianopsis contorta （Royle） Ma in Beijing. It is suggested that the flora of wild seed plant in the reserve possesses the typical temperate character and a certain transition property.