The afterlife of herbaceous plant species: A litter decomposition experiment in a temperate oak-hornbeam forest

Understanding the mechanisms of singular species and their traits impacts on ecosystem functions, is crucial in the era of unprecedented anthropogenic changes of the environment, e.g. to predict changes in carbon and nutrient cycling connected with species shifts. It may allow us to take protective measurements and mitigate the negative effects of global changes. Litter decomposition is a crucial process shaping nutrient cycling in ecosystems. Studies on decomposition in forest ecosystems are mainly limited to foliar litter. In contrast to woody plant species, our knowledge of decomposition of herbaceous plants is scarce. Thus, unanswered questions remain about the model that best describes the decomposition process of herbaceous plants. The relationship of decomposition rate to functional traits is unknown for this species pool. We used the litter bag method to determine the decomposition rate of 13 herbaceous plant species and four overstory tree species growing in a temperate oak-hornbeam forest. We showed that the litter decomposition rate and C and N release were higher in spring ephemerals than summer green herbaceous species, as the plants with small total individual aboveground biomass (TAB) and small total leaf area (TLA) decomposed the fastest. Our results demonstrate that in this generally acquisitive group of plants, size traits have a stronger impact on decomposition than economic traits. For almost all species, the two-phase exponential decay model explains the course of herbaceous species litter decomposition only slightly better than the single exponential model.