研究了陕西秦岭和秦巴山区连香树种群分布区域、生存立地环境、种群径级结构、自然繁殖更新特征和濒危因素等.结果表明:陕西连香树主要分布于秦岭北纬35°30′～37°48′之间的17个县,分布在海拔高度1 408～1 889m.区内种群均为远距离间断性片状、块状、散生和单株生存.秦岭连香树主要濒危因素为雌雄异株,且株间距离较远致使授粉不良,种子个形微小、质量轻,发育质量差.较厚的林下枯枝落叶层阻碍了种子与土壤的接触,即使种子发芽胚根也易枯萎,不易发育成苗.此外,人为砍伐使种源母树减少,砍伐后虽偶有从根基萌蘖新株,但萌蘖繁殖只能维持种群现状.由于自身繁殖更新的局限性和人类对其生存环境的破坏,致使连香树种群结构断代严重,种群消亡的危险性在不断加剧.%A survey was conducted to study the distribution area, site conditions, diameter class structure, natural regeneration characteristics and endangered factors of genus CercidiphyUum in Qinling and Qinba mountainous regions. Results show that CercidiphyUum mainly distributes in seventeen counties in Shaanxi, at north latitude 35°30' to 37°48' and an altitude of 1 408 to 1 889 meters. The plants in genus Cercidiphyllum are in isolated patches, clumps or as scattered individuals. The major endangered reasons for CercidiphyUum are dioecism and distant distribution, resulting in poor quality in pollination and seeds with small size and light weight. The litter under forests can also separate the seeds from the soil. Although the seeds can germinate from the root zone, they will wilt finally and are hard to go on for further development. Moreover, humans cut down the trees in CeradiphyUum to fulfill their requirement of wood, which contributes to the reduction of the seed trees. Some new plants could sprout from the root zone of the hewed trees; however, this vegetative reproduction could only maintain the current station of Cercidiphyllum population. Consequently, the limit of self-regeneration of CercidiphyUum and the destruction of mankind lead to the population age structure getting worse, and the crisis of population disappearance is increasingly serious.
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