Pine root exploration of standing dead tree trunks: a short-cut biocycling process

Aim of study: To characterize the colonization of Pinus herrerae roots in trunks of dead standing trees and to evaluate the composition of roots and decomposing tissues of standing dead trees. Area of study: Jaguariaiva, Parana state, Southern Brazil. Material and methods: This study evaluated root attributes in the soil, litter, and trunks of dead standing trees and the composition of wood and bark of trees. Root traits (length, mass mycorrhizal colonization, and mean nutrient concentrations), soil and organic layers, and mean nutrient concentrations of wood and bark for were analyzed by non-parametric test. Main results: Approximately 2 to 3.5 years after tree death, roots of adjacent trees in F and H horizon litter migrate into the wood/bark interface. Eight and a half years after tree death, roots of adjacent trees reached up to 3.3 m above the litter surface. At the wood/bark interface, a root mantle formed (length greater than 1 km m(-2)) with similar to 5% ectomycor-rhizal colonization. Root presence in the wood/bark interface reduced P, K, and Fe concentration of dead wood and Zn concentration in bark. Research highlights: Our results indicate that roots of P. herrerae are capable of colonizing dead tree trunks as a nutrient resource pool. This nutrient acquisition mechanism may function as a shortcut in the biogeochemical cycling of nutrients in forest systems.