Evidence to wood biodeterioration of tropical species revealed by non-destructive techniques

The wood biodeterioration process is one of the symptoms produced by biotic agents that affect the biomechanics of urban trees and reduce their useful life and environmental services. This process is mainly studied through methods that are time-consuming or destructive and provide little information regarding the degradation process at the cellular scale. Based on a non-destructive study of five tropical urban trees: Poincianella pluviosa (sibipiruna), Pterocarpus rhorii (aldrago), Rhamnidium elaeocarpum (saguaraji), Trichilia clausenii (Catiguá) and Lafoensia glyptocarpa (mirindiba rosa); the wood decaying zone, by xylophagous fungi, was analized. The trunk-wood samples containing the decaying zone were extracted with metal probes. Their microscopic anatomical structures were characterized and their microdensity and chemical composition analyzed by X-ray densitometry and X-ray fluorescence, respectively. Degraded cell wall fiber and vessels obstructed by mycelial mass were observed in wood decay zones. The presence of wood compartmentalized by the formation of extractive deposits was also observed, as a possible resistance mechanism varying among species. Likewise, phosphorus (P), calcium (Ca), calcium/manganese molar ratio and wood density increase were observed in barrier zones, while iron (Fe) was related to the decay zone. Altogether, the present study show for detailed evaluation of the wood biodeterioration process at the microscopic scale. The potential of non-destructive techniques for application in the physiological analysis of trees was also demonstrated. [Display omitted] •Non-destructive techniques were used for tree natural decay process analysis at microscopic scale.•The compartmentalization process was analyzed by an anatomical, physical and chemical approach.•The barrier zone is demarcate by the cellular arrangement in different directions and from occlusions of extractives in longitudinal elements.•The defense mechanism is characterized by the wood density and pH (Ca / Mn) increase, and the distribution of Ca and P in parenchymal cells.•The increase of Fe and Mn in decay zones are indicators of the metabolic process of pathogenic fungi.