Soil physical-chemical aspects influence the fine roots parameters of Pinus elliottii Engelm. stands in southern Brazil

Planted forests make use of strategies to increase the efficiency in the use of available soil resources, such as the production of fine roots to absorb nutrients and water which are factors limiting tree growth. Thus, the assessment of fine roots production in forest stand is crucial to understand the tree nutrient dynamic. This study aims to evaluate the interaction between physical-chemical attributes of a Rhodic Paleudult soil and the distribution of the fine roots of a Pinus elliottii plantation grown in southern Brazil. Biomass and density of fine roots, calcium (Ca), magnesium (Mg), soil organic matter (SOM), pH, base saturation and cations exchange capacity, clay, and soil density, at soil depths of 0-5, 5-10, 10-15 and 15-20 cm, were evaluated. The total production of fine roots biomass in the 0-20 cm layer produced was 824.9 kg ha-1, with greater accumulation in the 0-10 cm layer, where 57.4% of the total fine roots were concentrated. The fine roots density varied from 0.38 to 0.53 g dm-3, decreasing in subsurface layers of 10-20 cm. The biomass and density of fine roots of P. elliottii were influenced by the higher concentrations of Ca, Mg, SOM, pH, base saturation, and cations exchange capacity, which can contribute to greater absorption of nutrients and, consequently, increase in productivity of a plantation.