兴安落叶松天然林生物量及生产力的研究

A STUDY ON THE BIOMASS AND PRODUCTIVITY OF THE NATURAL LARIX GMELINII FORESTS

依据生物量标准木２３７株、解析木８１４株以及３５５块标准地实测材料对内蒙古大兴安岭林区三个气候区兴安落叶松天然幼、中龄林的生物量和净初级生产力进行了分析比较。结果表明，兴安落叶松天然林的生物产量明显受热量带的影响。残差分析证实了ＶＡＲ模型ＩｎＷ＝Ｉｎａ＋ｂＩｎＤ＋ｃＤ或ＩｎＷ＝Ｉｎａ＋ｂＩｎＤ￣２Ｈ＋ＣＤ￣２Ｈ在估测兴安落叶松天然林生物量方面的应用价值，该模型对相对生长率随Ｄ或Ｄ￣２Ｈ皇线性变化的情况更为适合。本文还给出了各气候区适宜的林分密度和叶面积指数范围。

The distribution area of Larix gmelinii in the Da Xingan Mountain,Inner Mongolia,was divided into three zones.They are Southeastern Zone,Central Zone and Northern Zone,respectively.The biomass and net primary produ- ctivity of the natural young- and middle-aged stands of Larix gmelinii in the three zones were studied, based on the analysis of biomass from 237 sample trees,allometric dimension analysis of 814 trees,and field investigations co- nducted in 355 plots. An allometric model,InW= lna + blnD + cD or lnW = lna + blnD￣2H+ cD￣2H,which incorporates a variable allometric latio(VAR),was used to fit to the biomass data of the bolewood,bolebark, live branch and leaf compo- nents of Larix gmelinii.Residual analysis showed that the VAR model signi- ficantly improved the estimation of live branch,leaf and bolebark biomass, and it provided less biased estimates compared with the CAR model,InW= lna + blnD or lnW =We lna + blnD￣2H. The VAR model is superior to the CAR model,particularly when the allometric relationships change in a linear fas- hion with increasing stem sizes. The aboveground biomass and net primary productivity of the stands we- re respectively 85.37 t· ha￣-1 and 9.86 t· ha￣-1·a￣-1for young-aged group at the Southeastern Zone;56.74 t·ha￣-1 and 7.29 t·ha￣-1·a￣-1 for young-aged group,72.34 t·ha￣-1 and 6.26 t·ha￣-1·a￣-1 for middle-aged group at the Central Zone;and 41.81 t·ha￣-1 and 5.29 t·ha·a￣-1 for young-aged group,55.62 t·ha￣-1 and 5.02 t·ha￣-1·a￣-1for middle-aged group at the Northern Zone.These data sho- wed that the biomass and net primary productivity of the stands tended to decrease from the Southeastern Zone to the Northern Zone,or Southeastern Zone>central Zonc>Northern zone. The reference ranges of the suitable density and leaf area index for sta- ands of different zones were also given in this paper.