David Kniha
Senior Engineer
Authors
Junbin Zhao Mikhail Mastepanov Cornelya Klutsch Hanna Marika Silvennoinen David Kniha Svein Wara Runar KjærAbstract
No abstract has been registered
Authors
Junbin Zhao Cornelya Klutsch Hanna Marika Silvennoinen Carla Stadler David Kniha Runar Kjær Svein Wara Mikhail MastepanovAbstract
ABSTRACT Drained cultivated peatlands are recognized as substantial global carbon emission sources, prompting the exploration of water level elevation as a mitigation strategy. However, the efficacy of raised water table level (WTL) in Arctic/subarctic regions, characterized by continuous summer daylight, low temperatures and short growing seasons, remains poorly understood. This study presents a two‐year field experiment conducted at a northernmost cultivated peatland site in Norway. We used sub‐daily CO 2 , CH 4 , and N 2 O fluxes measured by automatic chambers to assess the impact of WTL, fertilization, and biomass harvesting on greenhouse gas (GHG) budgets and carbon balance. Well‐drained plots acted as GHG sources as substantial as those in temperate regions. Maintaining a WTL between −0.5 and −0.25 m effectively reduces CO 2 emissions, without significant CH 4 and N 2 O emissions, and can even result in a net GHG sink. Elevated temperatures, however, were found to increase CO 2 emissions, potentially attenuating the benefits of water level elevation. Notably, high WTL resulted in a greater suppression of maximum photosynthetic CO 2 uptake compared to respiration, and, yet caused lower net CO 2 emissions due to a low light compensation point that lengthens the net CO 2 uptake periods. Furthermore, the long summer photoperiod in the Arctic also enhanced net CO 2 uptake and, thus, the efficacy of CO 2 mitigation. Fertilization primarily enhanced biomass production without substantially affecting CO 2 or CH 4 emissions. Conversely, biomass harvesting led to a significant carbon depletion, even at a high WTL, indicating a risk of land degradation. These results suggest that while elevated WTL can effectively mitigate GHG emissions from cultivated peatlands, careful management of WTL, fertilization, and harvesting is crucial to balance GHG reduction with sustained agricultural productivity and long‐term carbon storage. The observed compatibility of GHG reduction and sustained grass productivity highlights the potential for future paludiculture implementation in the Arctic.
Authors
Paul Eric Aspholm David Kniha Hans Geir Eiken Snorre Hagen Ida Marie Bardalen Fløistad Ingrid Helle Søvik Ane-Sofie Bednarczyk Hansen Simo Maduna Cornelya Klutsch Finn-Arne HaugenAbstract
No abstract has been registered
