Basic wood density and moisture content of 14 shrub species under two different site conditions in the Chilean Mediterranean shrubland

Abstract

Aim of study: The aim of this study is to provide information on species-specific basic wood density (g cm-3) and moisture content (%) in Mediterranean shrublands. Area of study: The study covers two sites of the sclerophyllous shrubland in central Chile, Cortaderal (34°35’S 71°29’W) and Miraflores (34°08’S 70°37’W), characterized by different climatic and topographic conditions.  Materials and methods: The sampling area covers 4,000 m2 over four plots at two sites. Shrub species were identified and size-related attributes such as height and crown size measured. A total of 322 shrubs were sampled at 0.3 m aboveground to determine basic wood density and moisture content. Species-specific differences and similarities were analyzed by multiple pairwise comparisons (post-hoc tests) and by ordination and hierarchical clustering. Main results: We found high variation across species in wood density (0.46-0.77 g cm-3) and moisture content (41.6-113.1%), with many significant differences among species in wood density and among sites in moisture content. Because intraspecific variability could not be explained by shrub size and pronounced differences in wood density (0.49-0.64 g cm-3) also occurred between species of the same genus  (e.g., Baccharis linearis and Baccharis macraei), our results suggested that phylogenetic affinity may be less important than adaptation to local conditions. Research highlights: The values presented here were variable according to the type of species and environmental conditions, necessitating the determination of basic wood density (BWD) and moisture content at site – and species-specific level. The provided BWD estimates allow converting green volume to aboveground biomass in shrubland areas and are an essential source of information for estimating the carbon stocks.