Spatial variability of humus forms in some coastal forest ecosystems of British Columbia

Abstract

The spatial variability of 5 humus form properties (thickness, acidity, total C, total N and mineralizable-N) was examined in 3 coastal forest sites of different tree species composition (western hemlock, Douglas-fir and western redcedar), humus forms, and ecological site quality using variogram and kriging. Humus form properties were found spatially dependent and the kriging interpolation between sample locations unbiased for all 5 properties and in all 3 sites. The overall range of spatial dependence ranged from 46 to 1 251 cm, but varied with property and site. The average range for the humus form properties increased from 109 cm (total N) to 704 cm (mineralizable-N), and that for the sites increased from 275 cm (western hemlock) to 581 cm (Douglas-fir). It appears that humus forms in each site occur in polygons with the lateral dimension ranging from 100 to 700 cm. The spatial pattern of each property in each site was portrayed in contour maps. © 1995 Elsevier/INRA.