裂叶沙参分布区域和生物学生态学习性的调查

濒危植物裂叶沙参(Adenophora lobophylla Hong)已发现的天然分布区在四川西北部金川县的安宁、曾大、卡撒、马尔邦、观音桥五个乡,分布面积估计不超过5000km2,根据文献记载和50年代采集的标本分析,裂叶沙参的分布区正在缩小。裂叶沙参以有性生殖为主,在外界干挠和春旱严重的条件下也营无性生殖。在海拔2700m以下地区,裂叶沙参星散分布,生长发育不良,年龄结构老化,种群呈衰退趋势。在较为适生的海拔区间(2700-2900m),裂叶沙参生长正常,花果产量高,年龄结构合理。在海拔2900m以上地区,裂叶沙参分蘖数、花果量减少,个体寿命缩短。裂叶沙参所处群落可分为山杨、山棉花林;旱生多刺灌丛或灌丛;旱生灌草丛;和旱生草丛。裂叶沙参种群在各群落中均为伴生种,受到群落不同程度的影响。

INVESTIGATION ON THE DISTRIBUTION AREA AND CHARACTERISTICS OF BIOLOGY AND ECOLOGY OF ADENOPHORA LOBOPHYLLA (CAMPANULACEAE),AN ENDANGERED SPECIES

The endangered species Adenophora lobophylla population distributes in the northwest area of Sichuan province Jinchuan county,the all area is estimated not more than 500 km 2.According to evidence of the literature and spacemen collected in 1950's,the distribution of A.lobophylla population is reducing.In the normal condition,the reproduction of A.lobophylla ppopulation is mainly sexual.However,when suffered the external serious disturbance and drought in the spring,it could make asexual reproduction.The distribution area below altitude 2700m A.lobophylla population performs scatter distributive pattern,not good at growth and development, and declining tendancy of population.In the better condition,at altitude 2700-2900m the A.lobophylla population performs normal growth and development,higher yield of flower and fruit and reasonable age structure.Above the altitude 3000m,the number of stem tiller,flower and fruit is decreased,and the life span is shortened.The communities including A.lobophylla populations could be classed to be Populus davidiana Dode forest;xerophilous thorny brushwood or brushland;xerophilous brush grassland and xerophilous thick growth of grass.A.lobophylla populations live in these communities and are influenced by many external factors.