邓恩桉胸径生长对模拟硫、氮复合沉降的响应

应用二次回归旋转设计方法,安排硫、氮复合沉降对邓恩桉幼林影响的模拟实验,研究邓恩桉幼龄林胸径增长量对模拟硫、氮复合沉降的响应。排除年龄生长的影响,建立邓恩桉胸径生长响应的回归方程:■=0.776 3+0.193 5x1-0.125 6x2-0.510 0x1x2-0.245 0x12-0.597 5x22,分析硫、氮复合沉降对胸径增长的影响。结果表明,硫编码值为0.394 9(纯硫为28.20 kg.hm-2.a-1)和氮编码值为-0.105 1(纯氮为64.78 kg.hm-2.a-1)时,邓恩桉胸径年增长量可望达到最大0.84 cm。

Effect of simulated N and S combined deposition on DBH of Eucalyptus dunnii

The experiment about the effect of similated sulphur(S) and nitrogen(N) combined deposition on the growth of diameter at breast height(DBH) of young Eucalyptus dunnii plantation was arranged by the method of quadratic regression revolution design.The response of DBH in E.dunnii layer to sulphur(S) and nitrogen(N) combined deposition was studied.Eliminated the growth of age,the mathematical models: ■=0.776 3+0.193 5 x1-0.125 6 x2-0.510 0 x1x2-0.245 0 x21-0.597 5 x22 describing the above relations were established.As for the growth of DBH,their single effect,marginal effect and combined effect between sulphur(S) and nitrogen(N) were analyzed.The results showed that the best combination was S 28.20 kg·hm-2·a-1 and N 64.78 kg·hm-2·a-1 deposition respectively,which indicated that the growth of diameter at breast height would reach 0.84 cm·a-1.