Forest degradation modifies litter production, stoichiometry, and
decomposition dynamics in Southern Temperate Forests.
Abstract
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 regulates the carbon and nutrient cycling. However, it is
unclear how degradation affects litter decomposition and carbon and
nutrient dynamics. The main objective of this study was to evaluate the
effect of forest degradation on the production and decomposition of
litter and C:N:P stoichiometry dynamics in a temperate forest in
south-central Chile. 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. The litter production, decomposition, and C, N, and P
concentrations were evaluated monthly for one year. 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. The
remanent litter mass reached 56% in the mature forest, while it was
only 93% in the degraded forest. Decomposing litter showed the lowest
C:N and C:P ratios in the mature forest during most of the year. The
balance between inputs and outputs yielded a greater accumulation of
litter in the mature forests. Our results strongly suggest that
anthropic degradation has altered litter quality, production,
decomposition, and nutrient dynamics. Further research should be focused
on assessing how changes in litter dynamics affect natural forest
regeneration and soil biogeochemical functioning.