Shade shoot structure and productivity of evergreen conifer stands. Tests of three alternative hypotheses
1992
Leverenz, J.W. (Umeaa Univ. (Sweden). Inst. foer Fysiologisk Botanik)
The current annual increment (wood volume) of stands of evergreen conifers on a research site in Sweden, was found to be significantly correlated with the maximum ratio of shoot to leaf silhouette area of shade-acclimated shoots (Rmax). Neither the slope nor the intercept of the regression was significantly different from that published earlier relating maximum mean annual increment of British stands to Rmax. Moreover, a strong correlation between wood volumen increment and Rmax also occurs when data from four countries are combined. Wood density was not significantly correlated with Rmax. Harvest index for stand grown conifers more than 25 year old, was also not correlated with Rmax. Estimated net biomass production (excluding fine roots) was significantly correlated with Rmax (R2=0.82, F=17.7) These new analyses could not be used to disprove the hypothesis that variation in shade shoot structure of evergreen conifers has a measurable effect on maximum biomass production.
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