The role of terrestrial productivity in regulating aquatic dissolved organic carbon concentrations in boreal catchments ...

• Main Authors: Zhu, Xudan, Chen, Liang, Pumpanen, Jukka, Ojala, Anne, Zobitz, John, Zhou, Xuan, Laudon, Hjalmar, Palviainen, Marjo, Neitola, Kimmo, Berninger, Frank
• Format: Dataset
• Language: English
• Published: Dryad 2022
• Subjects: FOS Biological sciences; boreal catchments; DOC; terrestrial productivity; GPP; Discharge; catchment size; landscape; Laudon; Northern Sweden
• Online Access: https://dx.doi.org/10.5061/dryad.wpzgmsbp9; https://datadryad.org/stash/dataset/doi:10.5061/dryad.wpzgmsbp9

The past decades have witnessed an increase in dissolved organic carbon (DOC) concentrations in the catchments of the Northern Hemisphere. Increases in terrestrial productivity may be a reason for the increases in DOC concentration. The aim of this study is to investigate the impacts of increased terrestrial productivity and changed hydrology following climate change on DOC concentrations. We tested and quantified the effects of gross primary production (GPP), ecosystem respiration (RE) and discharge on DOC concentrations in boreal catchments over three years. As catchment characteristics can regulate the extent of rising DOC concentrations caused by the regional or global environmental changes, we selected four catchments with different sizes (small, medium and large) and landscapes (forest, mire and forest-mire mixed). We applied multiple models: Wavelet coherence analysis detected the delay-effects of terrestrial productivity and discharge on aquatic DOC variations of boreal catchments; thereafter, the ... : 1. Study site Four catchments with different sizes (small, medium and large) and landscapes (forest, mire and forest-mire mixed) were studied. Hereafter, following the catchment named ‘S’, ‘M’ and ‘L’ state the catchment sizes while ‘forest’, ‘mire’ and ‘mix’ show the land cover types. Three sub-catchments locate in Krycklan, about 50 km northwest of the city of Umeå in northern Sweden (64°14′ N, 19°46′E) (Fig S1). In Krycklan, C2[S-forest] is covered by forest with the size of 0.14 km2; C4[S-mire] of 0.19 km2 is covered by 40.4% of wetlands, and the remainder is forest; C6[M-mix] of 1.3 km2 is constituted by 72.8% of forest, 24.1% of wetland and 3.1% of lakes (Table 1). The climate is characterised as a cold temperate humid type with persistent snow cover during the winter season. The 30-year mean annual temperature (1981-2010) is 1.8 C, January -9.5 ◦C, and July 14.7 ◦C. The mean annual precipitation is 614 mm, mean annual mean runoff is 311 mm, giving an annual average evapotranspiration of 303 mm (Laudon ...