冷杉腐朽病研究:Ⅳ.冷杉腐朽病对经济出材影响的研究

Studies on Fir Decay in Aplinc Forest Regions of Western Sichuan Ⅳ. The Influence of Fir Decay on the Rate of Timber Producing

在四川西部高山冷杉林区,冷杉腐朽病的危害性在于降低了林分出材率、改变了林未材仲结构。通过2849株冷杉伐倒木测定表明,冷杉林木发生腐朽后,林种结构有明显的变化,优良林种下降,加工材增加。在冷杉林木出材率方面,腐朽木较健康木下降8.4～28.8％(平均14.9％)。冷杉林区冷杉林分出材率(Y),与林分年龄的腐朽率(X_1),林分径级的腐朽率(X_2)均呈极显著的负相关。回归方程分别如下: (?)=81.46-0.21X_1 (?)=82.35-0.23X_2 据此,岷江冷杉林、峨眉冷杉林出材率为Ⅱ级,而鳞皮冷杉林、长苞冷杉则属Ⅰ级出材等级。文中讨论了正确测定冷杉林分出材率方法和查对表,便于生产应用。

The damage caused by fir decay in alpine fir forest regions of western Sichuan has decreased the outturn rate of the stand and changed the structure of timber assortment. The determinations of 2, 849 felled trees of fir have shown that. after fir trees had decayed,excellent timber decreased while the processing timber increased. The outturn rate of the decayed trees was 8.4~28. 8% (averagedly 14. 9%) lower than that of the healthy. The outturn rate (Y) of fir stand has a marked negative correlation with the rotten rate (x_1) of the stand age and the rotten rate (x_2) of the stand diameterclass. The regression equations are as follows :. Y=81.46-0. 21 x_1 Y=82.35?.23x_2 Investigations have also shown that the outturn rates of Abies faxoniana and A. faberi are the second degree but those of A. squamata and A. georgei the first degree.