Conclusion
Our results highlight the importance of flow intermittence on river
meta-ecosystem dynamics and particularly on network-scale coarse organic
matter cycling. Drying, by promoting the accumulation of unprocessed
leaf litter, can affect the river network carbon processing and budget,
modifying the timing and quantity of organic matter transport to
recipient ecosystems (e.g. lakes, flood plains and oceans; Datry et al.
2018, Catalàn et al. 2022). However, intermediate drying extent could
potentially stimulate ecosystem functions of downstream ecosystems. Our
results are also some of the first to unravel the links between aquatic
and terrestrial functioning in river networks from a large-scale field
study (Scherer-lorenzen et al. 2022). By identifying where, when and
under which conditions organic matter may accumulate and hotspots of
decomposition occur, our research will help better predict impacts of
climate change on biogeochemical cycles. As climate change exacerbate
river drying in space and time, accounting for flow intermittence and
its effects on both biodiversity and ecosystem functioning is also key
to inform management actions that support healthy, functional ecosystems
which deliver benefits to our societies, such as pollution attenuation
(via microbial nutrient processing) and climate regulation (via carbon
cycling; Palmer and Ruhi 2019).