摘要
林木有效养分浓度区间为林木生长量(Y)对林木养分吸收量(X)的导数大于零的养分浓度(C)区间.依据林木的养分生产力方程1/C=(2/Cm)-[1/(CmXm)]X,当养分吸收量X等于有效吸收量上限Xm时,养分浓度C为有效浓度上限Cm;当养分吸收量X趋向于0时,养分浓度C趋向于起始浓度;由此给出有效养分浓度区间为Cm/2<C<Cm.桉树试验林样本分析与检验的结果表明,养分生产力方程在描述桉树树干中氮、磷、钾浓度与吸收量关系时具有较高的精确度;运用回归分析求出的不同林龄桉树树干有效养分浓度区间的曲线具有一定的实用价值.
The effective nutrient concentration range is defined as the range within which the derivative of tree growth (Y) with respect to nutrient uptake (X),dY/dX>0. According to the nutrient productivity equation, 1/C=(2/Cm)-X,when nutrient uptake reaches its effective upper limit, X=Xm, nutrient concentration reaches its limit, C=Cm; while as X approaches zero, C approaches its initial concentration, C0=Cm/2, giving thus the effective nutrient concentration range: Cm/2<C<Cm. Results from the analysis of stem samples collected from eucalyptus trial stands indicate that the nutrient productivity equation can well be applied for describing the relationship between 1/C and X for the three tested elements, nitrogen, phosphorus and potassium. Accounted for by their relatively high levels of accuracy, the estimated effective concentration range curves are of high value for practical use. The present study presents a new way of approach to the determination of critical nutrient concentration values for forest growth.
出处
《中南林业科技大学学报》
CAS
CSCD
2002年第4期1-6,共6页
Journal of Central South University of Forestry & Technology
基金
国家"八五"林业科技攻关专题<工业用材林施肥技术和地力维护措施研究>
"九五"国家林业科技攻关专题<纸浆材微生物应用与施肥技术研究>
挪威HYDRO公司资助的国际合作项目<中国南方人工林培育>的部分内容.
关键词
桉树
养分生产力
养分浓度
养分吸收
有效养分浓度区间
Eucalyptus
nutrient concentration
nutrient uptake
nutrient productivity
effective nutrient concentration range
