Self-Thinning in Even-Aged Natural Stands of Betula pubescens
- 1 October 1989
- Vol. 56 (2) , 264-268
- https://doi.org/10.2307/3565346
Abstract
The mass-density relationship of the shade intolerant species Betula pubescens Ehrh. does not conform to the self-thinning rule (which states that m = K.N.gamma. where .gamma. is equal to -1.5), the exponent (-1.37) differing significantly from -1.5 (p < 0.05). According to an extended allometric model, which predicts the relationships of the thinning exponent to allometric exponents derived from stand dimensions, this deviation from -1.5 can be attributed to the relatively high allocation of resources to radial growth and poor ability to add mass into the already occupied space. Crown depth growth in B. pubescens declines with increasing tree height, implying that surviving trees mainly increase their leaf area by radial growth (assuming that the leaf area index remains constant during thinning). Average mass density, estimated on the basis of stand weight and stand volume, decreases as a population develops. The performance of B. pubescens stands during self-thinning is in close agreement with the prediction of the extended allometric model.This publication has 0 references indexed in Scilit: