Biomass offine roots in different land cover types atthe ‘arc ofdeforestation’, Brazil

Abstract

This study aims to evaluate the effect of land cover type, soil properties, and vegetationstructure on fine root biomass, and examined how these factors affect diameter of fine roots. Thestudy was conducted in communities located in the Nova Ipixuna, Parauapebas and Pacajámunicipalities of Pará state. In each area, nine farms were selected; in each farm were sampled fiveplots, totaling 135 plots distributed into nine different types of land cover; at each plot, four soilsamples were collected to quantify the fine roots, vegetation cover was inventoried, and soil wascollected for physical and chemical characterization. Fine roots were separated into four differentclasses. Principal Component Analysis (PCA) were done for the soil and vegetation matrix and theywere compared with the fine root biomass PCA through a co-inertia analysis. Variability was highfor fine root biomass data. All land covers exhibited a high proportion of fine roots > 1 mm. The co-inertia analysis showed that the fine root biomass PCA share a common structure with vegetationPCA, with 37% of the variability being explained; however only 9% of the variability was explainedby the soil PCA. Our results highlight the importance of roots with diameters 2 mm was critical to thedifferentiation among land covers.

Keywords

• family farms
• amazon
• soil properties
• vegetation