Comparing direct and indirect leaf area measurements for Scots pine and Norway spruce plantations in Sweden

Abstract

The area of foliage absorbing solar radiation is often expressed as leaf area index (LAI). In this study, specific leaf area (SLA), leaf area at tree level (LA) and LAI at stand level were measured on eight experimental plots of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris), together with tree and stand measurements from biomass harvest. Both projected area and half total surface area were measured, and a model of the relationship between the units was constructed. SLA was larger for pine (61.62 cm 2 g −1) compared to spruce (50.2 cm 2 g −1) and showed a trend of decreasing higher up in the crown. Leaf area was significantly higher for Norway spruce compared to Scots pine on both tree and stand level. Models were constructed using diameter at breast height, tree height and stand basal area to estimate LA. The models were general site-independent models that can be used for easy estimations of single tree leaf area. Indirect measurement of LAI (LAIe) was shown to underestimate LAI with on average 30-73% depending on species and measurement technique. Using the extensive data collected, conversion models were constructed for estimating LAI from LAIe together with basal area, stem number and stand height. These species-specific conversion models will allow for more accurate estimations of LAI that can be used in mechanistic models of forest growth and for future estimates of LAI from remote sensing data.

Comparison of Methods for the Estimation of Total Inorganic Nitrogen Deposition to Forests in Germany

“…The approach by Kirchner et al (2014) has been developed for spruce stands but only 34 of the 104 plots included in this study were pure spruce stands. The leaf area index (LAI) in spruce stands is often higher than in pine stands (Panferov et al, 2009;Goude et al, 2019). Zhang et al (2003) found generally higher vd values for stands with higher LAI values.…”

How tree species, tree size, and topographical location influenced tree transpiration in northern boreal forests during the historic 2018 drought

“…Higher water demands due to higher leaf area or tree size can influence the way species respond to drought. In Scandinavian boreal forests, spruce tends to have a higher leaf area compared to pine of a given size, and commonly grows in stands reaching higher leaf area index (LAI; Cienciala et al, 1997;Goude et al, 2019). Spruce, however, has lower stomatal conductance, as indicated by its lower Q DZ (Figures 4 and 5).…”

A Raspberry Pi‐based camera system and image processing procedure for low cost and long‐term monitoring of forest canopy dynamics

“…leaf on or leaf off). Other studies where differences have occurred include Goude et al (2019) who concluded that both LAI-2000C and DHP techniques underestimated LAI (in two conifer species) compared to values derived from destructive biometric sampling, but that the digital HP method underestimated the 'true' values more than LAI200C method.…”