Verification of a Leaf Litter Decomposition Model Based on Long-term Field Trials in Gongga Mountain, Qinghai-Tibetan Plateau, China

Abstract Background and aimsAlthough litter decomposition is a vital soil ecosystem process in forest ecosystems, most decomposition models are based on short-term decomposition experiments. Prediction of long-term decomposition dynamics using short-term decomposition models may lead to unreliable results. A leaf-litter decomposition model was evaluated and verified using a long-term field trial in Gongga Mountain, on the eastern flank of the Qinghai-Tibetan Plateau, China. Methods A 90-month experiment employing 360 broad-leaf litter (five species) samples were conducted using the litterbag method at three elevations (2250 m, 2780 m and 3000 m a.s.l.) in Gongga Mountain. The remaining litter mass was measured to fit a mathematical decomposition model by different exponential functions (two-, three-, four- and six-parameters) and akaike information criterion (AIC). ResultsThe four-parameter model (B) employed for each litter type among the four functions showed the highest R2 and lowest AIC value. The fast and slow decomposition rate constant (kf and ks) for a given litter at 2250 m was higher than that observed at 3000 m. ConclusionsThese results indicated that the four-parameter exponential function (two-pool model) was recommended as a suitable decomposition model of long-term broadleaf litter decomposition at different elevations on Gongga Mountain.