SPATIAL-DISTRIBUTION AND ESTIMATION OF FOREST FLOOR COMPONENTS IN A 37-YEAR-OLD CASUARINA-EQUISETIFOLIA (FORST) PLANTATION IN COASTAL SENEGAL

Forest floor spatial variability was studied in a coastal Casuarina equisetifolia plantation in Senegal. Systematic sampling was monitored along a 300 m transect perpendicular to the shore. The forest floor was divided into litter components (leaves, catkins, cones and twigs), fecal pellets and undetermined material. Total accumulation was 106 t ha(-1); litter components accounted for 50%; accumulation of fecal pellets averaged 15 t ha(-1). Components were not related to the local tree stand. The spatial pattern of each component was investigated by three complementary statistical methods operating at different scales, including spatial autocorrelations and geostatistics. Twigs and leaves were randomly distributed. The fecal pellet semivariogram was characterized by a high nugget effect and a large range of spatial dependence. Cones and catkins exhibited more complicated patterns with a large-scale trend and periodical structures. These results show that forest floor components exhibit particular spatial patterns, probably in relation to their production and decomposition specificity.