Termites amplify the effects of wood traits on decomposition rates among multiple bamboo and dicot woody species

Abstract

Summary1. Wood decomposition is a key process in the terrestrial carbon cycle, controlling carbon storage with feedback to climate. In (sub) tropical forest, termites are major players in wood decomposition, but their role relative to that of microbial decomposers and wood traits of different tree species is poorly understood. The current literature also has strong bias towards dicot tree decomposition, while abundant woody monocots, particularly bamboos, also contribute greatly to (sub) tropical carbon cycling. 2. Here, we present the first experiment to disentangle effects of dead wood traits and termite activity on decomposition of 66 angiosperm species of wide-ranging phylogenetic position: 31 bamboos, eight non-bamboo Poaceae, 18 eudicots and nine magnoliids. We incubated dead stems of up to 4 size classes per species in a 'common garden' in tropical S China. We tested the hypotheses that (i) dead wood of bamboo (monocots) is less decomposable than dead wood of eudicots or magnoliids; (ii) both microbial-and termite-driven decomposition show negative relationships with initial wood density and with dry matter content. 3. Bamboo wood generally decomposed more slowly than dicot wood but only slightly slower at given wood density or diameter. Wood decomposition in both bamboo and dicot clades decreased with wood density or dry matter content. Termites contributed greatly to this pattern, explaining 53.4% of the variance in wood decomposition and preferentially attacking dead wood of lower initial density, which corresponded with thicker outer culm walls in the case of bamboo species. Thus, termites strongly strengthen the relationship between species' wood traits and litter decomposition as driven by microbial activity. 4. Synthesis. These previously unknown relationships among dead wood quality, diameter, termites and decomposing microbes of both woody monocots and dicots will advance our understanding of the driving mechanisms of (sub) tropical wood decomposition and its contribution to the global carbon cycle.

Tree leaf and root traits mediate soil faunal contribution to litter decomposition across an elevational gradient

“…Indeed, the mesofaunal contribution was strongly regulated by litter traits, being higher in nutrient‐rich and less lignified litter than in recalcitrant litter across elevations (Figure a). This finding supports some previous empirical evidence for the mesofaunal contribution (Fujii et al., ; Schädler & Brandl, ) and shows an analogy with the contribution of (meso‐ and) macrofauna to decomposition (Coq, Souquet, Meudec, Cheynier, & Hattenschwiler, ; Garcia‐Palacios et al., ; Liu et al., ). However, other papers reported a greater role for mesofauna in more recalcitrant litter or nutrient‐poorer sites (Milcu & Manning, ; Perez et al., ; Yang & Chen, ).…”

Wood decomposition is more strongly controlled by temperature than by tree species and decomposer diversity in highly species rich subtropical forests

“…Our results show that macro-invertebrates have little effect on wood decay, while microbial decomposers are the main agents of decay during the observed period. This finding contradicts recent studies from subtropical forests that found significantly lower decay rates of wood and bamboo in subtropical forests when termites were excluded (Liu et al 2015, Eichenberg et al 2017. However, both studies were conducted in forest communities with far lower leaf area index and a more open canopy structure than our system.…”

Changes in the Contribution of Termites to Mass Loss of Dead Wood among Three Tree Species during 23 Months in a Lowland Tropical Rainforest

“…These results are in accordance with the findings of Liu et al (2015), who reported the role of termites in enhancing the effect of wood traits on decomposition. Moreover, root foraging occurs more on dead wood hollowed by termites, thereby, accelerating nutrient cycling (Lu et al, 2013).…”