Nr. Hulugalle et Jn. Ndi, CONTRIBUTORY FACTORS TO SOIL SPATIAL VARIABILITY IN AN ULTISOL .2. RETENTION OF LIVING TREES INSITU FOLLOWING LAND CLEARING, Communications in soil science and plant analysis, 24(11-12), 1993, pp. 1409-1419
The effect of retaining living trees in situ following manual land cle
aring on soil physical properties was studied in a Typic Kandiudult in
southern Cameroon. Soil compaction in the surface 100 mm was greatest
with complete clearing and least under forest, with retention of livi
ng trees resulting in soil compaction levels which were intermediate t
o both the former. Soil compaction in the surface 100 mm also increase
d with increasing distance from the tree trunk (or tree stump with com
plete clearing). Both the above observations were attributed to a comb
ination of high root density, high macrofaunal activity, high ground c
over, high organic matter content and low traffic under forest and at
the base of trees or tree stumps. Increasing soil compaction also occu
rred with increasing depth, and was attributed to the existence of few
biopores in the subsoil horizons. Absence of biopores was thought to
be due to low root densities in the subsoil caused by a combination of
low macroporosity, low air porosities during the wet season and low p
H. In comparison to sub-humid and semi-arid ecologies, therefore, the
beneficial effects of retaining living trees in situ following land cl
earing at this site were less.