桂东南三个主要薪炭树种的养分特点及其幼林的生态效益

本文对博白和岑溪县薪炭试验林的窿缘按、刺栲和大叶相思三个树种的养分特点进行了初步分析，提出窿缘桉属氮磷钙锰养分相关型．刺栲属氮磷钾锰养分相关型，大叶相思属磷钾养分相关型；发现三个树种对钙元素具有强烈的吸收特点。五年生幼林土壤肥力明显提高，生态效益显著。

NUTRIENT CHARACTERISTIC OF THREE MAJOR FUELWOOD SPECIES AND ECOLOGICAL EFFICIENCY OF THE JUVENILE FUEL-FORESTS IN SOUTH-EAST OF GUANGXI

In this paper,a preliminary study was made on the nutrient characteristic of three major fuelwood species in the fuel-forests of Bobei ad Cenxi counties of Guangxi.The three species are Eucalyptus exserta,Acacia auriculijormis and Costanopsis hystrix.The results showed that E. exserta belonged to N-P-Ca-Mn nutrient type,A.auriculiformis to p-k type and C.hystrix to N-P-K-Mn type.The characteristics were correlated with their height growth. In this study, we still discovered that the three species had a characteristic of strongly absorbing of element Ca,and the soil fertility level of the 5 year fuel-forests was greatly improved and their ecological efficiency was highly remarkable.