Soil fertility of cohune palm (Attalea cohune) dominant forests compared to non-cohune forests in northwestern Belize

Abstract

We studied how soils vary between cohune palm and non-cohune forests and assessed whether the forests differed in soil fertility. We sampled soil profiles from six cohune palm forests and eleven non-cohune forests. Our laboratory analyses included soil organic matter (SOM), extractable phosphorous, and the total concentration of 10 elements. Each soil characteristic was subjected to a mixed-effects model with depth, forest type, and the interaction between the two as factors that were grouped by excavation. Total phosphorous, sulfur, and SOM differed significantly between the two forest types, with higher values in non-cohune forests, on average. SOM, extractable phosphorous, and nine elements showed statistically significant changes with depth. The interaction between depth and forest type was significant for eight elements and SOM. The elemental concentrations were consistently maintained with depth in the cohune forests. Meanwhile, the elemental concentrations in non-cohune forest soils decreased with depth for all elements except calcium and magnesium, which increased concentration with depth. Cohune forest soils and non-cohune forest soils differ in distinct ways but these differences do not relate to key measures of soil fertility. Cohune palm forest soils exhibit consistent elemental concentrations with depth, which suggests bioturbation or another phenomenon that redistributes nutrients.