榧树的资源分布与生态习性

Distribution and ecological characteristics of Torreya grandis in China

为期5 a的调查研究表明,榧树Torreya grandis的自然分布区在我国的中亚热带和北亚热带,25°~32°N,109°~121°E,跨浙、皖、苏、闽、赣、黔、鄂等7省广大地区。分布区的年均气温为15.2~18.7℃,极端最低气温-17.0^-8.1℃,年降水量1000~1900 mm,≥10℃年积温为4758~5940℃。垂直分布随地理位置而异,在北亚热带的大别山海拔可达800~1100 m,黄山和天目山可达1200~1500 m,中亚热带南部武夷山可达1800~2000 m。在缓风、向阳、少受寒潮危害的高海拔地段,极端最低温-18.0℃,≥10℃年积温3 500℃,榧树生长结果正常。南部武夷山区海拔1800~2000 m,≥10℃年积温仅3200℃,但由于极端最低温较高(-15.0℃以上),榧树呈高大乔木,结实正常。榧树喜肥,在有机质丰富,土壤疏松,质地由砂壤到轻黏,pH 5.2~6.5的土壤中生长发育良好。

The objective is to get the living condition of Torreya grandis Fort.ex Lindl.（Chinese torreya） to improve its cultivation.Through five years＇ investigation in its distribution areas and the related literatures,the research showed that the natural distribution area of Torreya grandis was the mid and northern sub-tropical belt in China（25°-32°N,109°-121°E） and covered a vast area of 7 provinces,including Zhejiang,Anhui,Jiangsu,Fujian,Jiangxi,Guizhou,and Hubei.The average temperature of the distributional area was between 15.2 and 18.7 ℃,the absolute low temperature ranged from-17.0 and-8.1℃,the annual rainfall reached between 1 000-1 900 mm,and the annual accumulative temperature ≥10 ℃ was in the range of 4 758 and 5 940 ℃.Vertical distribution varied with geographical location.For instance,in the mid sub-tropical belt when moving from north to south,T.grandis grew at altitudes of 800-1 000 m in the Dabie Mountains,1 200-1 500 m in the Huangshan Mountain and Tianmu Mountain areas,and 1 800-2 000 m in the Wuyi Mountains.In the high-altitudeareas with light wind,abundant sunshine,and few cold waves,and where the absolute low temperature was-18.0 ℃ With an annual accumulated temperature ≥10℃ of 3 500℃,T.grandis grew and fruited normally.Additionally,in the Wuyi Mountains of South China although the accumulated temperature≥10 ℃ at 1 800-2 000 m was only 3 200 ℃,T.grandis grew tall and fruited normally due to a higher absolute low temperature that was over-15.0 ℃.T.grandis thrived best in fertile soil,which in the optimum areas of this study consisted of soil with rich organic matter,a soil texture of loose,sandy loam to light clay,and pH of 5.2-6.5.