Deadwood decomposition modulates habitat structure and enhances resource availability within forest ecosystems. Deadwood decomposition is influenced by a combination of abiotic and biotic factors, wherein climatic variables, tree species, and wood characteristics play fundamental roles. However, the scarcity of studies conducted in dry and semiarid regions restricts our understanding of deadwood decomposition dynamics. Here, we studied the decomposition of logs in four plots across an elevation gradient spanning approximately 1000 m (from 1477 to 2317 m a.s.l.). The site was a burnt reforestation of different pine species in a Mediterranean mountain (Sierra Nevada, SE Spain). Logs of a range of diameters were cut to a similar length (75 cm), and their density loss was monitored over 15 years. We fitted three different types of functions (linear, negative exponential and negative sigmoidal) to evaluate the temporal trajectory of decomposition across the elevation gradient. Average wood density loss through the 15-year period ranged from 30.4 % to 63.3 % depending on the elevation plot, and it was highest at an intermediate elevation. The negative sigmoidal equation showed the best fit, but all functions rendered similar half-life values, which ranged between 12.8 and 29.4 years depending on the elevation plot. Contrary to most studies, larger-diameter logs experienced a quicker decomposition process, which could be linked to increased moisture retention and greater activity of large invertebrates in the larger-diameter logs. The variations observed across the elevation gradient are consistent with expectations on how the interaction between precipitation and temperature influences decomposition rates. The observed decomposition patterns in these mountain forests indicate a relatively rapid process, and underline the vital contribution of deadwood biological legacies to the preservation of soil fertility in the Mediterranean region.