Subarctic catchment water storage and carbon cycling – Leading the way for future studies using integrated datasets at Pallas, Finland

Abstract

Subarctic ecohydrological processes are changing rapidly, but detailed and integrated ecohydrological investigations are not as widespread as necessary. We introduce an integrated research catchment site (Pallas) for atmosphere, ecosystems, and ecohydrology studies in subarctic conditions in Finland that can be used for a new set of comparative catchment investigations. The Pallas site provides unique observational data and high-intensity field measurement datasets over long periods. The infrastructure for atmosphere-to landscape-scale research in ecosystem processes in a subarctic landscape has recently been complemented with detailed ecohydrological measurements. We identify three dominant processes in subarctic ecohydrology:(a) strong seasonality drives ecohydrological regimes, (b) limited dynamic storage causes rapid stream response to water inputs (snowmelt and intensive storms), and (c) hydrological state of the system regulates catchment-scale dissolved carbon

The Spatiotemporal Variability of Snowpack and Snowmelt Water 18O and 2H Isotopes in a Subarctic Catchment

“…It has an area of 4.42 $${\mathrm{k}\mathrm{m}}^{2}$$ and the elevation ranges from 268 to 364 m a.s.l. The infrastructure for monitoring meteorological variables has a history of over 80 years (Marttila et al., 2021), while intensive hydrological measurements have been possible since 2008. Research activities at the Pallas site are growing, particularly since 2014, when ecohydrological investigations started being conducted.…”

“…As a result, characterizing the spatial and temporal variation of snowpack and meltwater 18 O and 2 H isotopic composition for their use in hydrology research, in snow‐influenced regions, remains challenging (Beria et al., 2018; Penna et al., 2018). Studies that address the spatial and temporal variability of snowpack and snowmelt water 18 O and 2 H isotopes on a catchment scale (Marttila et al., 2021) are rare because snow and meltwater samples in high latitude and altitude regions are difficult to obtain (Pu, Wang, et al., 2020; Tetzlaff et al., 2018). Due to the limited number of samples available for isotopic analysis, adequately capturing of the gradual 18 O and 2 H enrichment of melting snowpack and meltwater can be undermined (Taylor, Feng, Williams, et al., 2002; Taylor et al., 2001).…”

Flushing or mixing? Stable water isotopes reveal differences in arctic forest and peatland soil water seasonality

“…The Pallas catchment is located in Northern Finland, roughly 170 km north of the Arctic Circle. Monitoring history in the wider Pallas region dates back to 1935 when the first weather stations were installed, and research infrastructure has been gradually expanding (Lohila et al, 2015), especially during the last decade (Marttila et al, 2021). The total area of the catchment is 4.42 km 2 , altitude ranges from 268 to 364 m a.s.l.…”

Coupling of Water‐Carbon Interactions During Snowmelt in an Arctic Finland Catchment

“…A more detailed description of measurements in the catchment can be found in Marttila et al. (2021).…”