三江县油茶林低产状况的初步研究和改造建议

Initial Study and Proposal Cencerning Low yielding Oiltea Camellia in Sanjiang County,Guangxi

用路线和样方调查方法，调查三江县的同乐、独峒、八江、同坪、林溪５个乡的油茶林。调查结果表明：三江县油茶林低产原因是多数油茶林用点播造林，导致林木个体生长和经济性状良莠混杂；同一片林老、中、幼树同存，４５年生林以老、中龄树为主；林分单位面积密度过大（２２００株／公顷～４８００株／公顷）；铲山抚育造成土壤肥力衰退；油茶树的营养水平较低。建议从当地现有的优良品种中选育良种，用育苗造林取代点播造林，用梯级整地造林、割草抚育和摘果收获取代直接在坡地上点播造林和铲山抚育以及林地捡籽收获，油茶林尚未郁闭前间种豆类及其他改良土壤的作物。

Route and quadrat are used to investegate oiltea camellia in Tongle,Dudong,Bajiang,Tongping and Linxi,totally five townships in Sanjiang county.The reasons of low yielding oiltea camellia lies are in afforestation of dibbling mostly that causes a poor individual growth and economic effect;old timber,adult tree and young growth simultaneously are in a forest with a big stand density (2 200 individuals/hm 2 to 4 800 individuals/hm 2);weeding and cultivation (named YOUBA locally) made decline of soil fertility and malnutrition of oiltea camellia plants.Authors' suggestions for improvement are selection of local improved varieties planting is used instead of afforestation of dibbling,afforestation in terrace preparation of soil, intercrop oiltea camellia and soya beans before canopy closure of oiltea camellia forest.