Does Mowing and Plant Composition Alter the Activity of Litter Decomposition? - A Case Study on Solidago Stand Restoration Methods

Abstract

Soil ecosystem services are facilitated by the breakdown of organic matter. The speed of this decomposition process is predominantly influenced by the nature of the plant material undergoing decomposition and the abundance and variety of organisms involved in processing organic matter. Consequently, any disruption to the soil ecosystem will impact the decompo-sition process. Invasive plants, such as Solidago species, cause a significant ecological threat to natural habitats, emphasizing the need to develop effective and environmentally safe methods to control their presence. This study utilized decomposition rates as indicators of soil health in the context of grassland restoration following Solidago invasion. The field experiment on Solidago species removal and land restoration was established in April 2020 in a 5 × 3 factorial arrangement in a completely randomized block design with four replications. Various seed mixtures (including grasses, grasses with legumes, seeds collected from a seminatural meadow, and the use of fresh hay with no seeds) were sown, and different mowing frequencies (1, 2, and 3 times per year) were implemented. Two types of litterbags were prepared. The large litterbags were prepared using fibreglass mesh (aperture 5 mm) to allow free microbial and small soil animals, and small litterbags with nylon (aperture 0.02 mm) were used to allow free microbial. Three seasons ([June 2021, August 2021, and April 2022) of data on litterbag biomass reduction were collected. Two hypotheses were tested: (1) the plant species composition used in the restoration process affects litter decomposition rates, and (2) mowing regimes influence litter decompo-sition rates. Seed mixture, mowing, season and interaction between seed and season were significant with both mesh sizes (p <0.05). The findings revealed that decomposition rates were higher in plots with the highest species diversity (seminatural meadow), indicating a positive correlation between increased species diversity and enhanced soil processes. Additionally, mowing two and three times per season positively influenced the decomposition process. In conclusion, higher plant species composition and mowing more than once increase the decomposition rates and can serve as a valuable tool for identifying appropriate grassland management practices.