四川小桐子分布特点及适生环境选择初探

四川小桐子主要沿金沙江、安宁河和雅砻江干流及其支流干热河谷呈窄带状水平分布,垂直分布范围为500~1 600 m,最高1 910 m,最适高度为1 600 m以下;分布形式有零星分布、团条状分布和成片分布.小桐子在攀西河谷上段、下段和二半山3个典型垂直气候带上的树高、地径、果重、千粒重和含油率差异不显著;在500~1 600 m海拔梯度内营养和生殖生长无明显差异;在山地红壤上生长较差,山地燥红土、山地粗骨红壤和冲积沙壤上生长均较好,但含油率差异并不显著;土层深厚(50~120 cm)有利于小桐子生长;小桐子在各个坡向都生长良好,阳坡、半阳坡生长更好;在山地下部、沟谷河滩处生长和结果量好于山地中上部.

Preliminary Study on Distribution Characteristics of Jatropha curcas and Selection of Its Suitable Habitat in Sichuan Province

In Sichuan Province,Jatropha curcas is mainly distributed within a narrow horizontal belt along dry-hot river valleys of the Jinsha River,the Anning River,the Yalong River and their main tributaries.J.curcas is usually distributed in scattered,clustered or patched pattern in the province.It was showed by investigation that the optimal habitat for J.curcas was below 1 600 m in Sichuan Province,with average distribution elevation between 500 m and 1 600 m,and 1 910 m as the highest. It was indicated that there were no significant differences in plant height and basal diameter of the trees,the thousand-grain weight and the seed oil content sampled from trees growing on 3 typical vertical climate zones,i.e.,on the Mount Erban zone,on the upper and the lower reaches of Panxi River.Neither there were not evident differences in sexually reproductive or vegetative growth of the plants that grew within elevation level within 500~ 1 600 m.The results showed that J.curcas plants grew better on dry red soil,mountainous coarse red soil and on the alluvial sandy soil than on the common mountainous red soil.However,there was no significant difference in the oil content of the seeds sampled from trees growing on different soil conditions.It was showed that deep soil(soil depth was from 50 m to 120 cm) was beneficial to growth of J.curcas.It was showed that J.curcas could grow well on varied slope aspects,though it grew better on sunny and semi-sunny slopes.The results also showed that J.curcas trees growing at the bottom of the slope,in the valley and on the river banks could grow and fruit better than those growing on the upper and middle parts of the slopes.