甘肃省徽县和康县银杏古树的调查分析

CHARACTERISTIC ANALYSIS ON THE ANCIENT GINKGO TREES IN HUI COUNTY AND KANG COUNTY OF GANSU PROVINCE

对甘肃省徽县和康县银杏古树进行了调查,两县各有银杏古树66株,总计132株,其中一级古树51株;二级古树12株;三级古树45株;另有20株古树树龄目前尚不明确。徽县银杏古树集中分布于嘉陵镇,其田家河上、下坝村分布最多,占到全县银杏古树的71.4%;康县在王坝乡、岸门口镇、阳坝镇和白杨乡等4个重点乡镇有银杏古树的分布,占到该县整个银杏古树资源的80.30%。两县银杏古树垂直分布在海拔1 250 m以下,一般生长在庙宇、古道附近及村庄房前屋后或路边的山坡、河谷地上。综合分析各项生长指标,徽县和康县平均树高分别为19.8 m、27.1 m;平均树龄分别为1 176年、500年;平均胸径分别为1.16 m、1.22 m;平均冠幅分别为163.84m2、334.89 m2;树龄、树高、胸径和冠幅的最大值依次为3 000年、54.0 m、4.82 m(基)和35.6 m×36.5 m。

Ancient Ginkgo trees were invesgated in Hui County and Kang County. The result showed that there were totally 132 ancient Ginkgo trees and each had 66 trees in the two counties, of which 51 trees were at first class level, 12 at second level, 45 at third class level, and the other 20 not clear. In Hui County, Ginkgo trees were concentrated in the Jialing town, of which, Tianheshangba Village and Tianhexiaba Village distributed the most, accounting for 71.4% of the whole ancient Ginkgo trees＇in Hui County. In Kang County, there were four key towns , that is, Wangba, Anmenkou, Yangba and Baiyang Town etc, distributed the ancient Ginkgo trees, accounting for 80.30% of the whole Ginkgo trees resources in Kang County. The vertical distribution of the trees in two counties was both blow an altitude of 1 250 m, and most of the trees generally grew in temples, near the ancient road and on the roadside slopes or the river valley of the village, which was in front or behind of the house. With comprehensive analysis of various growth index in Hui County and Kang County, the average tree height was 19.8 m, 27.1 m; the average age 1 176 a, 500 a; the average DBH （diameter at breast height） 1. 16 m, 1.22 m; the average crown breadth 163.84 m2, 334.89 m2 ; the maximum of tree age, tree height, DBH and crown diameter successively 3 000 a, 54.0 m, 4.82 m （in base） and 35.6 m 36.5 m.