Wood decomposition is an important process in forest ecosystems. Woody debris (WD) provides shelter and a nursing medium for plant seedlings and habitat for many arthropods and other organisms, representing a substantial reservoir of carbon in forests. Therefore, it is important to disentangle the effects of factors affecting wood decomposition rates. 

In a study published in Forest Ecology and Management, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) conducted an experiment to examine the biotic and abiotic factors determining wood decomposition rates across a forest disturbance gradient.  

The researchers examined the decomposition of freshly cut logs of two native species with contrasting wood specific gravities (WSG) in a tropical montane rain forest landscape in Xishuangbanna, SW China. They measured the wood specific gravities (WSG) loss at intervals and total mass loss at the end of the experiment. 

They found that species and disturbance gradient categories had significant effects (weak effect for disturbance gradient) on wood decomposition rates when measured on a mass loss basis, but not on a WSG loss basis. 

When considering mass loss, they found logs of the species with low initial WSG and logs placed in open land decomposed faster. 

Moreover, afterlife effects of wood functional traits interacted with abiotic conditions and decomposition processes (microbial decomposition, macro-organisms (termites), photo-degradation) in a complex manner to determine wood decomposition rates. WSG loss was not a reliable predictor of mass loss. 

"Our results suggest that wood functional traits, in particular WSG and probably bark thickness, have important afterlife effects. However, these effects may have substantially different consequences for microbial decomposition, as compared to photo-degradation or decomposition by macro-organisms, such as termites", said Dr. Gbadamassi G.O. Dossa, first author of the study.