Spatial heterogeneity of dead fuel moisture content in a Larix gmelinii forest in Inner Mongolia using geostatistics

Abstract

Spatial heterogeneity of fuel moisture content determines the spread rate and direction of a forest fire. Research on the spatial heterogeneity of the moisture content of dead fuel of Larix gmelinii Rupr. showed that: (1) fuel moisture content in litter layer < semi-humus layer < humus layer, and the coefficient of variation decreased with sampling depth; (2) the sill value of the semi-humus layer was highest, the humus layer moderate, the litter layer the smallest, overall, the spatial heterogeneity of the semi-humus layer was the highest. The humus layer in the slant direction and three layers in a vertical direction showed strong spatial correlation with the lowest nugget coefficient of 0.0968; (3) the fuel moisture content of the humus layer showed strong spatial anisotropy; and, (4) estimating the total moisture content of the sampling site by stimulated sampling reasonable control of the sampling interval, and increasing the sampling intensity can reduce the error. When the sampling intensity is increased to more than 16 and the sampling interval 3 m, the standard error is < 15%. The spatial heterogeneity of fuel moisture content is best revealed by increasing sampling density, sampling in different fire seasons, and in different slope directions and positions. The results can provide a scientific basis for forest fire prediction and prevention.