四川省古银杏资源特征研究

2011年10月，通过资料收集和实地调查，对四川省古银杏资源的分布和结构特征进行分析。结果表明，四川省100～3000年生古银杏有974株，分布较集中，主要位于其中部的德阳、成都和雅安市。古银杏垂直分布海拔为400～3123 m，集中分布海拔为400～1200 m。在能确定性别的130株古银杏中，雌株占73.85％，雄株占26.15％。树高最高为50.0 m，最矮为2.0 m；树龄最大为3000年，最小为100年；胸径最大为4.80 m，最小为0.10 m；平均冠幅最大为29.0 m，最小为2.0 m。垂乳银杏有45株；复干银杏有55株；叶籽银杏仅1株。古银杏群共计15个，平均树龄在200～1100年，面积在500～8000 m^2。

Study on the Resources of Ancient Ginkgo Trees in Sichuan Province

In October of 2011, analysis on distribution and structure characterastics of ancient ginkgo trees in Sichuan Province was conducted through secondary data collection and field survey .The results showed that there were 974 ancient ginkgo trees （ 100 to 3000 years old ） in Sichuan Province , and mainly distributed in Deyang Chengdu and Yaan cities .The altitudinal distribution of ancient ginkgo trees was from 400 to 3 123 m, and the concentrated distribution altitude was from 400 to 1 200 m.Among 130 ancient ginkgo trees with knowing males or females, 73.85 % of which were female , and the rest were male .The highest tree was 50.0 m, the lowest tree was 2.0 m, the oldest was 3 000 years old, the youngest was 100 years old.The largest DBH was 4.80 m, the smallest DBH was 0.10 m.The maximum average crown breadth was 29.0 m, the minimum average crown breadth was 2.0 m.There were 45 strains of chichi ginkgo , 55 strains of mult-trunk ginkgoes and only one epiphylla .The total number of ancient ginkgo communities was 15 , with average age from 200 to 1 100 , and with the area from 500 to 8000 m^2 .