Trait variability differs between leaf and wood tissues across ecological scales in subtropical forests
Revealing how plant traits vary over disparate spatial scales and how ecological processes mediate such variation is important for understanding plant community assembly. However, to what extent does the distribution of trait variation among ecological scales differ between leaf and wood tissues and between physical and chemical traits? What are the consequences of resource competition and/or habitat filtering on the community assembly with respect to differences between leaf and wood traits, and between physical and chemical traits?
Subtropical evergreen broad-leaved forests in five sites in the Ningbo area (29°41–50′ N, 121°36–52′ E) in eastern China.
Traits of 96 woody plant species were sampled and variation of ten physical- and chemical-based leaf and wood traits were partitioned across six ecological scales (site, plot, species, individual plant, twigs and leaf age) using a linear mixed model.
From individual plant to site scales, variance partitions were distinct between leaf and wood traits. In leaf tissues, physical and chemical traits showed a consistent pattern, with the majority of variation found among species and individual plants, with little among plots. For wood tissues, the largest variation in physical traits was at the species and individual plant scales, with the largest variation in chemical traits observed at the plot scale. Variance partition was markedly similar within and across species.
Leaf and wood traits vary differently in relation to ecological scale, suggesting that trait variability is tissue-specific. The large variability of wood traits at the plot scale suggests a strong habitat filtering process. The large variation in leaf traits within plots may reflect niche differentiation across species and the importance of intra-specific variation that affects species co-existence. Our study demonstrated that physical and chemical traits may be independent. These decoupled trait axes may increase the dimensionality of niche space and facilitate species co-existence in forest communities.