Coprophilous fungal spores in modern lowland agropastoral ecosystems of Eastern-Central Europe reflect herbivore grazing pressure

Herbivores play a pivotal role in shaping vegetation dynamics, yet the intensity of past grazing remains difficult to reconstruct. Coprophilous fungal spores (CFS) are widely used to trace grazing by herbivores, but their potential to reflect grazing pressure has been less explored. Here, we present the first systematic assessment of CFS diversity to grazing pressure in European lowland agropastoral ecosystems, based on surface soil and dung samples from diverse habitats in Romania. While a quantitative reconstruction of herbivore density remains challenging due to animal mobility, we identified several CFS types associated with elevated grazing pressure. Sordaria, Podospora, Sporormiella, and Delitschia-types emerged as robust indicators of grazing pressure and/or herbivore density, while other taxa, such as Arnium, Bombardioidea, and Trichodelitschia-types, occurred only sporadically. Notably, Sordaria and Sporormiella abundance commonly peaked under heavy grazing. Additional fungal taxa with occasional coprophilous affinities, including Apiosordaria, Cercophora, Chaetomium, Coniochaeta, Gelasinospora, and Neurospora-types, also tracked grazing activity, and Glomus strongly indicated heavily grazed environments. CFS abundance was further elevated in moist habitats, spring samples, and areas where animals congregate. Independent CFS quantification as concentrations or percentages relative to the fungal sum is preferred over a pollen sum approach. Our findings also emphasise the value of plant indicators, such as Plantago lanceolata and Asteraceae for strengthening grazing regime reconstructions in Eastern-Central European lowlands. Key suggestions for future studies include broadening the range of fungal spore types used to reconstruct past grazing intensity, identifying CFS typical for certain dung, and standardizing identification and nomenclature protocols to enhance comparability across palaeoecological studies.