Boreal ecosystems, known for their abundant water resources and carbon-rich soils, are expected to face significant impacts from climate change. The expected changes include accelerated warming and notable shifts in precipitation patterns. These alterations in temperature and precipitation are likely to modify soil hydrology, affecting flow paths and the movement of water and solutes from terrestrial to aquatic (T-A) ecosystems. Despite increasing interest, there are still gaps in understanding how boreal landscapes respond to water variability under climate change. This is important as comprehending catchment hydrology mechanisms can elucidate the impacts of climate change on water and solute export.
To shed light on this concept, we conducted a six-year study in a forested experimental watershed, focusing on two types of headwater catchments: low-relief wetlands and steep hillslopes. We used the hydrograph separation method to analyze annual and seasonal pre-event and event water dynamics to understand how boreal landscapes respond to precipitation regime changes.
Our initial findings show that the boreal landscapes respond to changes in precipitation depending on the proportion of different landscape components and previous conditions. Steep hillslopes influence runoff due to their steep gradient, while antecedent conditions, such as soil moisture levels in hillslopes before precipitation events, affect solute export. In contrast, low-relief landscapes rely on nearby wetlands as essential water storage reservoirs, especially during storms.
Understanding how these landscapes respond to different events is necessary for predicting the impact of climate change on water and solute export from the T-A boreal ecosystem.