2025/11/13 by Boch, Steffen, Pichon, Noémie, Hölzel, Norbert +3
#FOS: Biological sciences #bryophyte #colonization #community recovery #disturbance experiment #land-use intensity #seed addition
paper · doi:10.14471/2025.45.011
In semi-natural grasslands, land-use intensification is considered as one of the major drivers of habitat degradation, leading to biodiversity decline. The recovery of biodiversity and ecosystem functions in grasslands after disturbances, i.e. the ability to return to previous conditions, is of particular importance from an economical but also a conservational point of view, as ecosystem functions ensure the provision of ecosystem services. Accordingly, sowing of seed mixtures is widely used to restore grasslands, often combined with sward disturbances to increase the establishment success. However, while sward disturbances initially affect vascular plants drastically, the effects on the bryophytes are largely unclear. Moreover, it is unclear whether seed addition affects bryophyte recovery and species richness and whether land‐use intensity interacts with the recovery of bryophyte communities after disturbances. To test the effects of disturbance, separately and in combination with seeding, along a gradient in land-use intensity on bryophyte communities, we established a full factorial experiment with each four 7 m × 7 m treatment subplots (control, seeding only, seeding and disturbance, distur- bance only) in 72 agricultural grasslands in Germany. In 2 m × 2 m quadrats per treatment subplot, we monitored the recovery of bryophyte communities over two years. Disturbances strongly decreased bryophyte richness and cover and led to a high Sørensen dissimilarity between disturbed and un- disturbed subplots. While richness and cover in general strongly decreased with increasing land-use intensity, the decrease in richness due to disturbance was strongest at low land-use intensity, where bryophyte richness was generally higher. In the second year of the experiment, species richness did not differ anymore between disturbed and undisturbed subplots, and species composition became more similar between disturbed and undisturbed subplots, indicating a recovery of the communities. How- ever, bryophyte cover did not recover. Interestingly, land-use intensity and seeding in general had no significant effect on the recovery of bryophyte species richness and cover. The quick recovery of bryophyte species richness indicates that grassland-restoration measures including disturbances and seed addition seem to have no detrimental effects on bryophyte diversity. However, ecosystem func- tions provided by bryophytes might be limited until bryophyte cover is fully restored.