Forest degradation modifies litter production, quality, and decomposition dynamics in Southern temperate forests

Abstract

Introduction Anthropic disturbances are driving unprecedented changes in forest ecosystem functions and biogeochemical processes, hindering the forests’ benefits to society. Litter decomposition is one of the most critical processes that regulate forests’ carbon and nutrient cycling. However, how forest degradation affects litter decomposition and elemental dynamics requires further examination. The main objective of this study was to evaluate the effect of forest degradation on the production and decomposition of litter and C,N, and P dynamics in a temperate forest in south-central Chile. Methods Litter traps and litter bags were installed in three Long Term Research Forest Plots (LTER) representing different conservation states: mature, secondary, and degraded Nothofagus forests. Results and Discussion The total litter input varied between 3.5 to 1.1 Mg ha–1 year–1 in the mature and degraded forests, respectively. We found the highest lignin and nutrient levels in the degraded forest and the lowest in the mature forest. In the mature forest, 44% of the initial litter was decomposed, while in the degraded forest it only reached 7%. Decomposing litter showed the lowest C:N and C:P ratios in the mature forest most of the year. The balance between inputs and outputs yielded a more substantial litter accumulation in the mature forests. Conclusion Our results strongly suggest that anthropogenic degradation altered litter quality and nutrient dynamics while decreasing litter production and decomposition.