Discrete riparian inflow points (DRIPs) transport dissolved organic carbon (DOC) from large areas to discrete sections of streams, yet the mechanisms by which DRIPs affect stream DOC concentration, cycling, and export are still unknown. Here, we tested four models that account for different hydrologic and biological representations to show that DRIPs generally reduce DOC exports by either diluting stream DOC (snowmelt period) or promoting aquatic metabolism (summer).

We applied CoupModel to quantify the impacts of natural and human disturbances to adjacent water bodies in regulating net CO₂ uptake of northern peatlands. We found that 1 m drops of the water level at the beaver pond lower the peatland water table depth 250 m away by 0.15 m and reduce the peatland net CO₂ uptake by 120 g C m^-2 yr^-1. Therefore, although bogs are ombrotrophic rainfed systems, the boundary hydrological conditions play an important role in regulating water storage and CO₂ uptake.

Stable isotope ratios (isotope values) of surface water reflect hydrological pathways, mixing processes, and atmospheric exchange within catchments. We used a water-balance-based mapping method, which represents patterns of surface flow and mixing, and added a regression-based correction step using catchment environmental characteristics to map water isotope ratios across all the rivers of New Zealand.

We introduce a new multi-process river sediment module for Earth system models. Application and validation over the contiguous US indicate a satisfactory model performance over large river systems, including those heavily regulated by reservoirs. This new sediment module enables future modeling of the transportation and transformation of carbon and nutrients carried by the fine sediment along the river–ocean continuum to close the global carbon and nutrient cycles.

Peatlands are a major stock of carbon that can be released as dissolved organic carbon (DOC), affecting carbon balance and downstream water quality. This study investigates the impact of peatland restoration on water balance and DOC exports using a simple modelling approach. The results suggest that the restoration can affect the water balance and the dynamics of DOC in the peatland. However, there is no major impact in the quantity of DOC released in a short-term period (3 years).