When and how much a non-native tree species changes the temporal patterns and biomass of litterfall input in subtropical streams

Abstract

Context In headwater streams, allochthonous litterfall input is an essential process to maintain the ecosystem functioning. The presence of non-native species in the riparian vegetation, with phenological characteristics distinct from those of most native tree species, can alter this process. Aims We evaluated the effect of the phenology of a non-native species (Hovenia dulcis) on the temporal patterns and biomass of litterfall input into streams by comparing one stream with (Hovenia stream) and another without (Native stream) H. dulcis in their riparian vegetation. Methods We quantified the litterfall input from native tree species and H. dulcis for 1 year by using buckets suspended above the streambeds. Key results The temporal pattern of litterfall input changed between streams, with quantitative differences between them during autumn and winter. In the Native stream, litterfall input was slightly higher in spring (∼79 g m−2 month−1), followed by winter (∼68 g m−2 month−1) and autumn (∼54 g m−2 month−1), whereas in the Hovenia stream, it was concentrated in autumn (∼126 g m−2 month−1). Conclusions and implications Our results indicated that the presence of H. dulcis in the riparian vegetation, when in high density, changes the temporal pattern and biomass of litterfall input into subtropical streams.