Specific respiratory activity (SRAC) was not significantly affected by treatments, although it tended to
be lower in soils under Vochysia sp. (data not shown).
Lower SRAC in soil under Vochysia sp. might be the
result of differences in organic substrate quality since
this genus is known to accumulate Al in foliage with
potential suppression of litter decomposers (GonzaÂlez,
1996). Pooled comparisons between agroforestry systems
and pasture also showed no differences for SRAC
(Table 4). The slightly higher SRAC in the surface soil
of pastures corresponded to the higher CMIN for
pasture soil.