Leaf Litter Decomposition in the Tropics Dynamically Recovers Following Experimental Disturbance Across Temporal Scales

Tartara, Arianna and Neira‐Salamea, Karla and Endara, María‐José and Escobar, Sebastián and Albuja, Genoveva Granda and Guevara‐Andino, Juan E. and Rödel, Mark‐Oliver and Sayer, Emma J. and López, Eva Tamargo and Villa‐Galaviz, Edith and Blüthgen, Nico and Heethoff, Michael (2026) Leaf Litter Decomposition in the Tropics Dynamically Recovers Following Experimental Disturbance Across Temporal Scales. Biotropica, 58 (2): e70198. ISSN 0006-3606

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Abstract

Litter decomposition by arthropods and microbes is a key ecosystem process in tropical forests, yet its response to disturbance and forest regeneration remains poorly understood. To investigate decomposition dynamics across forest succession, we conducted a space‐for‐time study in the Ecuadorian lowland Chocó spanning active cacao plantations and pastures (year 0), regenerating secondary forests (1–38 years), and old‐growth forest. We deployed litterbags in 32 plots, with aboveground litterbags accessible to arthropods and belowground ones allowing only microbial decomposition. Each litterbag contained standardized leaf litter from five common tree species. We modeled litter mass loss as a function of forest age and environmental variables associated with regeneration. To assess ecosystem resilience to new disturbances, we also tested how localized pulse perturbation (forest clearing) and fencing (large ground‐dwelling animal exclusion) influenced decomposition. Aboveground decomposition was primarily driven by surface temperature, elevation, tree biomass, and forest age, with trajectories varying by land‐use history. In sites recovering from cacao cultivation, decomposition followed a U‐shaped pattern, with lower rates during mid‐succession and again higher rates in old‐growth forest. This suggests that faunal decomposers respond non‐linearly to successional changes, likely reflecting shifts in habitat quality and resource availability. Belowground decomposition remained stable across forest ages and was shaped by soil moisture and soil carbon‐to‐nitrogen ratios, indicating strong environmental filtering on microbial communities. Perturbation reduced decomposition, especially aboveground, and the rates in fenced treatments did not reach undisturbed levels. Our findings highlight the effects of large‐ and small‐scale disturbances on an essential process for successful tropical forest restoration.