Physical and mechanical wood properties of ring-shaken chestnut (Castanea sativa) trees

Abstract

Ring shake is a defect that strongly affects chestnut (Castanea sativa Mill.) use and its occurrence is known to be mainly related to mechanical stress within a tree; however, few investigations have compared the physico-mechanical properties of healthy and shaken trees. Hence, the aim of this study is to compare the density, compression strength, bending strength (MOR), and shrinkages between healthy and shaken trees in coppice stands. The investigation was carried out in the Lazio Region in central Italy in trees with a cambial age between 6 and 25 years. The results showed that shaken trees had lower mechanical strength and shrinkages than healthy ones and that the physico-mechanical parameters might be used to predict ring shake occurrence in a specific geographic area. Geographical location strongly affected the physico-mechanical properties of the chestnut wood, and this factor influenced ring shake occurrence. MOR value was assumed to be the parameter that could be applied at almost all study sites to distinguish between shaken and healthy trees. There was no difference between the shaken and healthy portions of a disk inside the same tree.

Impact of Climate, Stand Growth Parameters, and Management on Isotopic Composition of Tree Rings in Chestnut Coppices

“…The dendrochronological series of the examined stands were short, and a weaker climate signal was expected due to the strong impact of vegetative regrowth from stumps. Chestnut is characterized by relatively wide tree rings [4][5][6], and it is not a particularly sensitive species in terms of dendrochronology [35]. Moreover, is not studied much from the dendrochronological point of view [36], and physiological studies of the species are also quite rare [9,37,38].…”

“…Stand thinning had a positive effect on WUEi after 1-2 years. Stand competition (indicated by shoots/stump and stumps/ha) positively influenced both WUEi and δ 18 O.as a multipurpose species for landscape enhancing and conservation in rural, mountain, and marginal area [3].In Italy, chestnut coppices (589, 362 ha) are important not only for wood production [4][5][6][7], but also because they represent an essential element of the culture and rural landscape, providing protection and ecosystem services essential for human well-being and conservation of resources [2,8].The species shows remarkable plasticity [9], although adequate ecological conditions must be guaranteed for its healthy development. In particular, the annual minimum rainfall should not be less than 600 mm, with optimal growth conditions found in areas where precipitation is above 900-1000 mm.…”

“…Thinning can have a positive effect on tree growth, improving stand resilience and resource use efficiency [10,12], as well as the physiological responses of trees to drought [13]. Thinning in chestnut has also been proven to increase wood quality conditions [4,5].Tree-ring features, such as tree-ring width (TRW) and tree-ring carbon and oxygen stable isotope composition, have proved to be powerful tools when investigating the impact of climate on the growth and physiology of tree species. Indeed, stable carbon isotopes (δ 13 C) is mainly controlled by stomatal conductance during carbon fixation (gs) and the rate of photosynthesis (A), both of which are driven by environmental conditions [14,15].…”

“…In Italy, chestnut coppices (589, 362 ha) are important not only for wood production [4][5][6][7], but also because they represent an essential element of the culture and rural landscape, providing protection and ecosystem services essential for human well-being and conservation of resources [2,8].…”

“…Thinning can have a positive effect on tree growth, improving stand resilience and resource use efficiency [10,12], as well as the physiological responses of trees to drought [13]. Thinning in chestnut has also been proven to increase wood quality conditions [4,5].…”