Table 1. Forest variables and the number of pixels per plot used in the analyses. Basal area weighted DBH (DBHB), mean height of dominant trees (H), stem number (N trees), basal area (BA), effective plant area index (PAIeff) and number of pixels of the airborne hyperspectral data used per plot (N pixels). The plots were located within approximately 3 km from each other.
Plot Species DBHB,
cm 		H,
m 		N trees,
ha–1 		BA,
m2 ha–1 		PAIeff,
m2 m–2 		N pixels
Pine 1 Pinus sylvestris 20.4 18.7 688 19.9 1.68 905
Pine 2 Pinus sylvestris 16.6 16.4 1760 28.0 2.14 1137
Pine 3 Pinus sylvestris 21.6 22.9 992 33.0 2.20 1139
Pine 4 Pinus sylvestris 30.3 25.1 272 17.6 1.30 689
Birch 1 Betula pendula, B. pubescens 14.0 18.6 1520 19.5 2.37 916
Birch 2 Betula pendula, B. pubescens 20.0 23.2 416 11.5 1.48 641
Birch 3 Betula pendula, B. pubescens 17.4 21.3 1184 22.9 2.56 1264
Birch 4 Betula pendula, B. pubescens 12.0 17.2 1904 16.8 2.44 759
Spruce 1 Picea abies 28.5 26.2 512 29.8 2.49 879
Spruce 2 Picea abies 44.8 34.3 368 46.0 3.25 744
Spruce 3 Picea abies 21.8 21.9 672 22.0 2.22 636
Spruce 4 Picea abies 29.7 26.0 400 22.9 2.84 688
Spruce 5 Picea abies 30.1 26.5 624 38.6 3.41 874
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Fig. 1. Contribution of woody elements to tree level reflectance based on four different models (M1 = Model 1, M2 = Model 2, M3 = Model 3, M4 = Model 4). Models 1–2 were estimated using Eq. 1 and Models 3–4 using Eq. 2. In Models 2 and 4, direct forest floor contribution was extracted from pixel reflectance before fitting the model. View larger in new window/tab.

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Fig. 2. Relationships between woody element contribution and effective plant area per vertical crown projection area (crown PAIeff) (left) and tree height (right), based on Model 4 (woody element contribution estimated using Eq. 2, with direct forest floor contribution first extracted from pixel reflectance).