A growing concern associated with fire in The Netherlands is estimating the spread of wildfire, however often the data needed to estimate canopy fires are lacking. The primary parameter required is canopy bulk density (CBD), which requires estimations of canopy gap fraction and leaf area index (LAI). The accuracy of three indirect methods of estimating CBD (a densiometer, hemispherical canopy photographs (HCP), and a LI-COR LAI 2200c plant canopy analyzer) was compared for three common tree species in the Netherlands [Scots pine (Pinus sylvestris L.), black pine (Pinus nigra Arnold) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)]. No differences between species were found for CBD, but the denser canopies in the Douglas-fir stands did have significantly lower gap fractions than the two pine species. The HCP method produced higher gap fraction estimates than the other two methods, but fell within reported ranges. LAI derived from HCP was the only variable that correlated significantly to CBD, although this correlation was not strong (R=0.53).
Published Date: 2020-10-01; Received Date: 2020-09-07