Litterfall and nutrients of three woody species planted in oil-disturbed
and non-disturbed soils in the Amazon Basin
Abstract
This study aimed to assess the influence of oil-disturbed soils of the
Ecuadorian Amazon on the biomass and nutrient production of three
6-year-old woody species. The investigation involved the placement of 9
traps of 0.25 m 2 in each permanent sampling plot (6
plots on disturbed soils and 2 on non-disturbed soils). The biomass was
collected biweekly for one year. The collected samples were separated
into leaves and branches and weighed, after which the amounts of
nitrogen (N), carbon (C), phosphorus (P), calcium (Ca), magnesium (Mg),
potassium (K), copper (Cu), zinc (Zn), manganese (Mn), iron (Fe), and
sodium (Na) in the leaves and branches were determined. The results of
the study showed that the specimens of the three species planted on
non-disturbed soils produced similar amounts of litterfall, which
amounted to 4.33±0.28 Mg ha -1 yr
-1, as those planted on disturbed soils, which
amounted to 4.66±0.24 Mg ha -1 yr
-1. However, specimens of Zygia longifolia
produced greater amounts of biomass, which amounted to 5.44±0.31 Mg ha
-1 yr -1, than specimens of
Piptadenia pteroclada, which amounted to 4.90±0.37 Mg ha
-1 yr -1, and Platymiscium
pinnatum, which amounted to 3.06±0.23 Mg ha -1 yr
-1. The concentrations of macroelements N, Ca, and Mg
were higher in the biomass of non-disturbed soils, whereas the
concentrations of microelements Fe, Zn, and Mn were higher in the
biomass of disturbed soils. Therefore, the use of these species in the
Amazon forests is important to maintain biomass production and nutrients
on disturbed soils, similar to non-disturbed soils.