Труды сотрудников ИЛ им. В.Н. Сукачева СО РАН

/ N. Bischoff [et al.] // Agric. Ecosyst. Environ. - 2016. - Vol. 235. - P253-264, DOI 10.1016/j.agee.2016.10.022 . - ISSN 0167-8809
Аннотация: The Kulunda steppe is part of the greatest conversion areas of the world where 420,000 km2 grassland have been converted into cropland between 1954 and 1963. However, little is known about the recent and future impacts of land-use change (LUC) on soil organic carbon (OC) dynamics in Siberian steppe soils under various climatic conditions. By investigating grassland vs. cropland soils along a climatic gradient from forest to typical to dry steppe types of the Kulunda steppe, our study aimed to (i) quantify the change of OC stocks (0–60 cm) after LUC from grassland to cropland as function of climate, (ii) elucidate the concurrent effects on aggregate stability and different functional soil organic matter (OM) fractions (particulate vs. mineral-bound OM), and (iii) assess climate- and LUC-induced changes in the microbial community composition and the contribution of fungi to aggregate stability based on phospholipid fatty acid (PLFA) profiles. Soil OC stocks decreased from the forest steppe (grassland: 218 ± 17 Mg ha?1) over the typical steppe (153 ± 10 Mg ha?1) to the dry steppe (134 ± 11 Mg ha?1). Across all climatic regimes, LUC caused similar OC losses of 31% (95% confidence interval: 17–43%) in 0–25 cm depth and a concurrent decline in aggregate stability, which was not related to the amount of fungal PLFA. Density fractionation revealed that the largest part of soil OM (>90% of total OC) was associated with minerals and <10% of C existed in particulate OM. While LUC induced smaller relative losses of mineral-associated OC than particulate OC, the absolute decline in total OC stocks was largely due to losses of OM bound to minerals. This result together with the high 14C ages of mineral-bound OM in croplands (500–2900 yrs B.P.) suggests that mineral-bound OM comprises, in addition to stable OC, also management-susceptible labile OC. The steppe type had a larger impact on microbial communities than LUC, with a larger relative abundance of gram-positive bacteria and less fungi under dry conditions. Our results imply that future drier climate conditions in the Siberian steppes will (i) result in smaller OC stocks on a biome scale but (ii) not alter the effect of LUC on soil OC, and (iii) change the microbial community composition more than the conversion from grassland to cropland. © 2016 Elsevier B.V.

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Держатели документа:
Institute of Soil Science, Leibniz Universitat Hannover, Herrenhauser Stra?e 2, Hannover, Germany
VN Sukachev Institute of Forest, Siberian Branch of the Russian Academy of Sciences, Akademgorodok 50, Krasnoyarsk, Russian Federation
Institute for Water and Environmental Problems, Siberian Branch of the Russian Academy of Sciences, Molodezhnaya Street 1, Barnaul, Russian Federation
Faculty of Biology, Altai State University, Prospekt Lenina 61a, Barnaul, Russian Federation
Institute of Biostatistics, Leibniz Universitat Hannover, Herrenhauser Stra?e 2, Hannover, Germany
Institute of Biology, Martin Luther University Halle-Wittenberg, Am Kirchtor 1, Halle (Saale), Germany
Soil Science and Soil Protection, Martin Luther University Halle-Wittenberg, Von-Seckendorff-Platz 3, Halle, Saale, Germany

Доп.точки доступа:
Bischoff, N.; Mikutta, R.; Shibistova, O.; Puzanov, A.; Reichert, E.; Silanteva, M.; Grebennikova, A.; Schaarschmidt, F.; Heinicke, S.; Guggenberger, G.

/ J. Cui, Z. Zhu, X. Xu [et al.] // Soil Biol. Biochem. - 2020. - Vol. 142. - Ст. 107720, DOI 10.1016/j.soilbio.2020.107720 . - ISSN 0038-0717
Аннотация: The impact of increasing amounts of labile C input on priming effects (PE) on soil organic matter (SOM) mineralization remains unclear, particularly under anoxic conditions and under high C input common in microbial hotspots. PE and their mechanisms were investigated by a 60-day incubation of three flooded paddy soils amended with13C-labeled glucose equivalent to 50–500% of microbial biomass C (MBC). PE (14–55% of unamended soil) peaked at moderate glucose addition rates (i.e., 50–300% of MBC). Glucose addition above 300% of MBC suppressed SOM mineralization but intensified microbial N acquisition, which contradicted the common PE mechanism of accelerating SOM decomposition for N-supply (frequently termed as “N mining”). Particularly at glucose input rate higher than 3 g kg?1 (i.e., 300–500% of MBC), mineral N content dropped on day 2 close to zero (1.1–2.5 mg N kg?1) because of microbial N immobilization. To cope with the N limitation, microorganisms greatly increased N-acetyl glucosaminidase and leucine aminopeptidase activities, while SOM decomposition decreased. Several discrete peaks of glucose-derived CO2 (contributing >80% to total CO2) were observed between days 13–30 under high glucose input (300–500% of MBC), concurrently with CH4 peaks. Such CO2 dynamics was distinct from the common exponential decay pattern, implicating the recycling and mineralization of 13C-enriched microbial necromass driven by glucose addition. Therefore, N recycling from necromass was hypothesized as a major mechanism to alleviate microbial N deficiency without SOM priming under excess labile C input. Compound-specific 13C-PLFA confirmed the redistribution of glucose-derived C among microbial groups, i.e., necromass recycling. Following glucose input, more than 4/5 of total 13C-PLFA was in the gram-negative and some non-specific bacteria, suggesting these microorganisms as r-strategists capable of rapidly utilizing the most labile C. However, their 13C-PLFA content decreased by 70% after 60 days, probably as a result of death of these r-strategists. On the contrary, the 13C-PLFA in gram-positive bacteria, actinomycetes and fungi (K-strategists) was initially minimal but increased by 0.5–5 folds between days 2 and 60. Consequently, the necromass of dead r-strategists provided a high-quality C–N source to the K-strategists. We conclude that under severe C excess, N recycling from necromass is a much more efficient microbial strategy to cover the acute N demand than N acquisition from the recalcitrant SOM. © 2020 Elsevier Ltd

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Держатели документа:
Key Laboratory of Agro-ecological Processes in Subtropical Region & Changsha Research Station for Agricultural and Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan, 410125, China
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Gongdong, 510640, China
Jiangsu Provincial Key Laboratory for Bioresources of Coastal Saline Soils, Jiangsu Coastal Biological Agriculture Synthetic Innovation Center, Yancheng Teachers' University, Yancheng, 224002, China
Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
School of Environment, Natural Resources & Geography, Bangor University, Gwynedd, LL57 2UW, United Kingdom
Department of Agricultural Soil Science, Department of Soil Science of Temperate Ecosystems, University of G?ttingen, G?ttingen, Germany
Institute of Environmental Sciences, Kazan Federal University, Kazan, 420049, Russian Federation
Agro-Technological Institute, RUDN University, Moscow, 117198, Russian Federation
Departamento de Ciencias Quimicas y Recursos Naturales, Universidad de La Frontera, Temuco, Chile
VN Sukachev Institute of Forest, SB-RAS, Krasnoyarsk, 660036, Russian Federation

Доп.точки доступа:
Cui, J.; Zhu, Z.; Xu, X.; Liu, S.; Jones, D. L.; Kuzyakov, Y.; Shibistova, O.; Wu, J.; Ge, T.