Multilevel analysis of six species of Phyllostachys bamboo and Arundo donax: preliminary survey on Italian grown stands

The paper focuses on a multilevel analysis considering six species of bamboo of the Phyllostachys family (P. bambusoides, edulis, iridescens, viridiglaucescens, violacescens, and vivax) and Arundo donax grown in temperate climates, most of them not already studied in the literature. The analysis is divided into three levels. The analysis at the first level (the microscopic scale) includes an anatomical study to assess the shapes and dimensions of the vascular bundles and the sclerenchymatic and parenchymatic tissues. At the second mesoscale level, the percentage and distribution of the fibres, voids and parenchyma are calculated. At the third level, the macroscopic one, a discussion of the influence of the microscopical properties on mechanical properties is carried out. Despite the limited number of specimens analysed at the microscale level, differences between species emerged from the analysis and influenced the macroscopic characteristic values. In particular, the morphology of the components differs, especially in the case of Arundo donax, which presents a unique distribution of its components along the culm wall. Different contents of each component are observed for the species analysed. Moreover, an innovative analysis that focuses on the presence and distribution of voids is presented, which have a fundamental role in the mechanical behaviour of this material. The analysis did not account for the influence of the environment on composition or anatomical and physical characteristics.