1 research outputs found
The contribution of insects to global forest deadwood decomposition
The amount of carbon stored in deadwood is equivalent to about 8âper cent of the global forest carbon stocks. The decomposition of deadwood is largely governed by climate with decomposer groupsâsuch as microorganisms and insectsâcontributing to variations in the decomposition rates. At the global scale, the contribution of insects to the decomposition of deadwood and carbon release remains poorly understood. Here we present a field experiment of wood decomposition across 55 forest sites and 6 continents. We find that the deadwood decomposition rates increase with temperature, and the strongest temperature effect is found at high precipitation levels. Precipitation affects the decomposition rates negatively at low temperatures and positively at high temperatures. As a net effectâincluding the direct consumption by insects and indirect effects through interactions with microorganismsâinsects accelerate the decomposition in tropical forests (3.9% median mass loss per year). In temperate and boreal forests, we find weak positive and negative effects with a median mass loss of 0.9âper cent and â0.1âper cent per year, respectively. Furthermore, we apply the experimentally derived decomposition function to a global map of deadwood carbon synthesized from empirical and remote-sensing data, obtaining an estimate of 10.9â±â3.2âpetagram of carbon per year released from deadwood globally, with 93âper cent originating from tropical forests. Globally, the net effect of insects may account for 29âper cent of the carbon flux from deadwood, which suggests a functional importance of insects in the decomposition of deadwood and the carbon cycle