Omnipresence of leaf herbivory by invertebrates and leaf infection by fungal pathogens in agriculturally used grasslands of the Swiss Alps, but low plant damage

摘要: Agriculturally used grasslands in the Alps are characterised by a trade-off between high fodder production some and plant species richness others. In contrast to production, however, little is known on relevance of biological interactions plants, invertebrate herbivores, fungal pathogens for Alps. At time when vegetation was fully developed, but prior agricultural use, we examined whether leaf damage herbivory pathogen infection, their diversity, affected functional group, land altitude. Moreover, studied extent diversity related each other, richness, standing crop. We recorded area damaged ten types five infection 12,054 leaves legumes, other forbs, graminoids collected 215 grassland parcels 12 valleys Swiss With 83 % all infested, were omnipresent. However, only 2.7 1.2 pathogens. Damage highest graminoids. More occurred traditionally mown sites at lower altitudes, while independent use Most found legumes from fertilised sites, whereas number unfertilised sites. Larger crop associated with higher per leaf. Neither nor correlated diversity. more rich parcels, level, tended be parcel level. Our results highlight omnipresence plant–herbivore plant–pathogen interactions. They suggest that current changes mowing grazing or abandonment decrease herbivory, fertilisation decreases As our did not reveal conservation conflicts diversities pathogens, as generally low, conclude protecting diverse low-intensity should maintained.