Temperature sensitivity of nutrient release from dung along elevation gradient on the Qinghai-Tibetan plateau

The temperature sensitivity of nutrient release from dung decomposition will influence ecosystem nutrient recycling in the future global warming. However, the relationship between temperature and nutrient release is not well understood. We conducted a 2-year-long study to understand the yak dung decomposition and its potential response to climate change along an elevation gradient from 3,200 to 4,200 m above sea level on an alpine meadow on the Qinghai-Tibetan plateau. Mass loss of different chemical components of dung [organic carbon (C), cellulose, hemicellulose, lignin, N, P, potassium (K), calcium (Ca) and magnesium (Mg)] significantly decreased with elevation. The ratios of C:N and N:P in the remaining dung increased significantly with decrease in elevation. The average temperature sensitivities (% A degrees C-1) (i.e., increase of the mass loss (%) per 1A degrees C temperature increase among elevations) were approximately 37, 75, 168, 41, 29, 37, 29, 34, and 31% per 1A degrees C warming within a 273-day decomposition period, which decreased with decomposition time, for organic C, cellulose, hemicellulose, lignin, N, P, K, Ca, and Mg, respectively. The temperature sensitivity of organic C mass loss is positively correlated to the C:N ratios in dung. The average temperature sensitivity of phosphorus mass loss was higher than that of nitrogen mass loss for the first 273 days and thereafter this situation was reversed.