Invasive forest pathogens affect the characteristics, microbial colonisation, and decomposition of leaf litter in streams

Invasive tree pathogens threaten forests worldwide, but their effects on streams are poorly understood. Nevertheless, infections that lead to changes in the characteristics of litter inputs may affect stream communities and ecosystem processes. We studied cross-ecosystem derived from Phytophthora cinnamomi, ×alni, Ophiostoma novo-ulmi infection Castanea sativa (chestnut), Alnus lusitanica (alder), Ulmus minor (elm) trees, respectively, by assessing physical chemical senescent leaves healthy, symptomatic, highly symptomatic individuals. Leaf three health statuses per species was then incubated laboratory microcosms microbial decomposers leaf decomposition were assessed. Tree significantly affected characteristics, decomposition, status trees conditioned these differently depending species. In C. sativa, had higher toughness, polyphenolic concentration slower than healthy trees. A. lusitanica, phosphorus concentration, lower carbon:phosphorus ratio faster Finally, U. minor, nitrogen carbon:nitrogen Effects mediated decomposer colonisation activity. The composition aquatic hyphomycetes associated with varied status. Most striking two-fold richness infected O. alters nutritional quality litter, potentially affecting functioning ecosystems strongly dependent riparian inputs.