Land use drives trematode dynamics in a restored stream system.

Urban freshwater ecosystems are subjected to multiple anthropogenic and natural stressors, emphasizing the need to evaluate and restore their ecological status amid ongoing biodiversity loss. While successional dynamics of free-living taxa are commonly assessed, the environmental drivers shaping parasite-host interactions in degraded and restored systems remain poorly understood. Here, we examined trematode species richness, overall prevalence, and community composition in first intermediate snail hosts across an urban stream system with a history of severe degradation and gradual restoration. Over two years of monthly sampling, we assessed differences in trematode dynamics across restoration stages and adjacent land-use types. We examined 6300 snails of 13 different species and identified 25 trematode species with an overall prevalence of 19.1%. Adjacent land use emerged as a consistent predictor of trematode dynamics, with agricultural sites supporting higher species richness and prevalence than forested or urban sites. In contrast, trematode community composition showed limited spatial turnover and did not differ substantially with restoration history or land use. Restoration history was not associated with trematode richness, overall prevalence, or community composition, suggesting quick recovery of trematode-host assemblages in recently restored habitats. The most abundant snail,