
pmid: 14969913
I compared the shoot structures of high-elevation red spruce (Picea rubens Sarg.) and balsam fir (Abies balsamea (L.) Mill.). Needle widths, thicknesses and perimeters were measured to estimate total leaf areas from measured projected leaf areas. Measured needle perimeter/needle width ratios differed significantly from estimated ratios that assumed needles were either rhomboidal or elliptical in cross section. The vertical and horizontal silhouette shoot area to total leaf area ratios (STAR(v) and STAR(h)) of the two species were negatively correlated with needle packing and canopy height. Red spruce had higher values of STAR(v) than balsam fir at each canopy height, but STAR(v) declined with canopy height at a similar rate in the two species. The STAR(h) values of the two species did not differ significantly at a given canopy height. Needle packing increased with canopy height at the same rate in the two species. Needle weight increased in red spruce and decreased in balsam fir with increased needle packing, but showed no significant dependence on canopy height. Red spruce had higher values of STAR(h) than balsam fir at low values of needle packing, but STAR(h) values converged at high values of needle packing. The generally comparable values of STAR, along with similar needle diameters, may imply that red spruce and balsam fir have similar collection efficiencies of wet and dry particles. Measurements of STAR may be used to estimate leaf area indices (LAI) more accurately when using indirect techniques.
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 5 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Average | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |
