The fate of 13 C 15 N labelled glycine in permafrost and surface soil at simulated thaw in mesocosms from high arctic and subarctic ecosystems

• Published in: Plant and Soil
• Main Authors: Ravn, Nynne Marie Rand, Elberling, Bo, Michelsen, Anders
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2017
• Subjects: Carbon and nitrogen isotopes; Carbon dioxide; Glycine; Permafrost thaw; Plant-microbe interactions; Tundra; Arctic; Cassiope tetragona; permafrost; Subarctic
• Online Access: https://curis.ku.dk/portal/da/publications/the-fate-of-13c15n-labelled-glycine-in-permafrost-and-surface-soil-at-simulated-thaw-in-mesocosms-from-high-arctic-and-subarctic-ecosystems(95339d87-0f34-4238-bed4-287d9dd4a9fd).html; https://doi.org/10.1007/s11104-017-3322-x

Background and aim: Nutrient distribution and carbon fluxes upon spring thaw are compared in mesocosms from high arctic and subarctic ecosystems dominated by Cassiope tetragona or Salix hastata/Salix arctica, in order to evaluate the possibility of plant and microbial utilization of an organic compound in thawing permafrost and surface soil. Methods: Double labeled glycine ( 13 C 15 N) was added to soil columns with vegetation and to permafrost. During thaw conditions ecosystem respiration 13 C was measured and 13 C and 15 N distribution in the ecosystem pools was quantified one day and one month after glycine addition. Results: Near-surface soil microbes were more efficient in the uptake of intact glycine immediately upon thaw than plants. After one month plants had gained more 15 N whereas microbes seemed to lose 15 N originating from glycine. We observed a time lag in glycine degradation upon permafrost thaw, in contrast to surface soil thaw. Conclusions: Our results suggest that both arctic plants and microorganisms acquire amino acids released upon spring and permafrost thaw. Despite indications of more efficient utilization of added substrate in the High Arctic than the Subarctic, we conclude that patterns of nutrient distribution are similar and predictions based on subarctic data valid for high arctic settings.