Temporal and spatial changes in soil micronutrients in managed Nothofagus pumilio forest of Tierra del Fuego, Argentina

MANSILLA, R.; PANCOTTO, V.;; MORETTO, A; NÓVOA-MUÑOZ, J.C; GÓMEZ-ARMESTO, A; PONTEVEDRA-POMBAL, X.; ESCOBAR, J

Environmental Earth Sciences

Springer

Año: 2016 vol. 75 p. 1 - 8

Soil organic components are important factorsin the quality and productivity of forest ecosystems. Timberharvesting reduces plant cover and the amount oforganic matter in forest floor layer, increases surface runoff,soil erosion and alters microclimatic conditions overlarge areas. These changes can have important implicationsfor nutrient cycling dynamics and soil organic mattermineralization. Fueguian temperate forests of Nothofaguspumilio (lenga) have been intensely harvested for the lastdecades, mainly by shelterwood-cut silvicultural system.Harvesting removes nutrients contained in logs from thesite, modifies light, temperature and soil humidity, constrainingnutrient cycling process. In this study, we evaluateavailable copper (Cua), zinc (Zna), iron (Fea), andmanganese (Mna) concentrations and reservoirs in standsthat represent a chronosequence and their respective primaryforests (controls): stands cut 1 year ago, stands cut5?10 years ago, and stands harvested more than 50 yearsago. Concentrations of Zna and Cua in primary forest were39.9 and 2.6 mg/kg, and increased in harvested sites to 60.5 and 3.2 mg/kg, respectively. Fea and Mna concentrationsshowed similar ranges in both harvested and controlsites. Recent harvested sites showed the highest Cua concentrations.Micronutrient reservoirs showed similar rangesin both harvested and primary forests. We concluded thatmicronutrient availability changes at short term after forestharvesting; thus, the inclusion of soil fertility assessment inforest management plans should be incorporated to preservethe fertility of lenga forests soils and ensuresustainability.