The relative changes of spruce increment in the air-polluted regions of Upper Orava (Slovak Republic), evaluated by multiple regression
1993
Dursky, J. | Smelko, S. (Technicka Univ., Zvolen (Slovakia). Lesnicka Fakulta)
Data on changes of basal area increment in consequence of pollutant load in the region of the Upper Orava (Slovak Republic) are presented. The index of increment (IUP) for each tree was calculated according to the relation [1]. Then, by step regression analysis, from a large number of considered factors those that influenced the index (Tab.2) were separated - defoliation; d.b.h.; crown length; bio-social status of tree; micro-stand density and ages. Statistically insignificant influence on IUP was had by: tree height; micro-site class of the tree species; area of crown mantle; and stem damage. A multiple linear regression model was derived [3] and for the chosen comparison base (crown defoliation=10) according to the relation [2] the increment changes were calculated (Fig. 1). The multiple coefficient of correlation was 0.38 and the average error of determination (IUP) according to the model [2] was 37.50.
显示更多 [+] 显示较少 [-]