Seasonally changing interactions of species traits of termites and trees promote complementarity in coarse wood decomposition

Complementary resource use by functionally different species may accelerate ecosystem processes. However, how co-variation in plant traits and animal traits promotes complementarity through temporal plant-animal interactions is poorly understood, even less so in detrital systems, thereby hampering our fundamental understanding of decomposition and carbon turnover. We hypothesized that, in seasonal subtropical forests where termites are major deadwood decomposers, trait complementarity of both termite species and tree species should promote overall deadwood decomposition through different seasons and years. Findings from a four-year coarse wood decomposition experiment involving 27 tree and 5 termite species support this hypothesis. Phenological and mandibular traits of the two most abundant termite species controlled wood decomposition of tree species differing in wood traits, through the seasons over four years, thereby promoting overall deadwood decomposition rates. Our findings indicate that complementarity in functional trait co-variation in plants and animals plays an important role in carbon cycling.

Methods
The article describes a detailed study conducted in two forest sites in Zhejiang Province, East China, focusing on the decomposition of logs from various tree species to understand environmental and biological factors influencing wood decay. The study utilized 81 healthy adult trees from 27 species, creating 648 log samples for decomposition experiments. Data collection involved placing logs in designated plots and monitoring them over several years with the help of micro-weather stations to gather information on environmental conditions such as soil temperature, moisture, and wind.

For data on wood decomposition, the study assessed volume loss by visually estimating log surface area reduction using a grid system, and depth measurements in termite tunnels to calculate volume loss. Termite species were identified and quantified to understand their role in decomposition, and their traits like body size and mandibular width were measured to assess their feeding capabilities.

Wood traits were also meticulously recorded, including density, dry matter content, and chemical composition such as carbon, nitrogen, phosphorus, lignin, and cellulose content. This comprehensive dataset from field measurements, laboratory analysis, and environmental monitoring provided a robust foundation for evaluating the interactions between wood traits, termite activity, and environmental conditions in wood decomposition processes.