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Nitrogen pools and cycles in Tibetan Kobresia pastures depending on grazing

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dc.contributor.author Sun Y.
dc.contributor.author Schleuss P.
dc.contributor.author Pausch J.
dc.contributor.author Xu X.
dc.contributor.author Kuzyakov Y.
dc.date.accessioned 2019-01-22T20:35:50Z
dc.date.available 2019-01-22T20:35:50Z
dc.date.issued 2018
dc.identifier.issn 0178-2762
dc.identifier.uri https://dspace.kpfu.ru/xmlui/handle/net/147889
dc.description.abstract © 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Kobresia grasslands on the Tibetan Plateau comprise the world’s largest pastoral alpine ecosystem. Overgrazing-driven degradation strongly proceeded on this vulnerable grassland, but the mechanisms behind are still unclear. Plants must balance the costs of releasing C to soil against the benefits of accelerated microbial nutrient mineralization, which increases their availability for root uptake. To achieve the effect of grazing on this C-N exchange mechanism, a 15NH4+ field labeling experiment was implemented at grazed and ungrazed sites, with additional treatments of clipping and shading to reduce belowground C input by manipulating photosynthesis. Grazing reduced gross N mineralization rates by 18.7%, similar to shading and clipping. This indicates that shoot removal by grazing decreased belowground C input, thereby suppressing microbial N mining and overall soil N availability. Nevertheless, NH4+ uptake rate by plants at the grazed site was 1.4 times higher than at the ungrazed site, because plants increased N acquisition to meet the high N demands of shoot regrowth (compensatory growth: grazed > ungrazed). To enable efficient N uptake and regrowth, Kobresia plants have developed specific traits (i.e., efficient above-belowground interactions). These traits reflect important mechanisms of resilience and ecosystem stability under long-term moderate grazing in an N-limited environment. However, excessive (over)grazing might imbalance such C-N exchange and amplify plant N limitation, hampering productivity and pasture recovery over the long term. In this context, a reduction in grazing pressure provides a sustainable way to maintain soil fertility, C sequestration, efficient nutrient recycling, and overall ecosystem stability.
dc.relation.ispartofseries Biology and Fertility of Soils
dc.subject 15 N labeling
dc.subject Grassland management
dc.subject Gross mineralization
dc.subject Intensive grazing
dc.subject Kobresia pygmaea
dc.subject Nitrogen uptake
dc.title Nitrogen pools and cycles in Tibetan Kobresia pastures depending on grazing
dc.type Article
dc.relation.ispartofseries-issue 5
dc.relation.ispartofseries-volume 54
dc.collection Публикации сотрудников КФУ
dc.relation.startpage 569
dc.source.id SCOPUS01782762-2018-54-5-SID85045736001


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  • Публикации сотрудников КФУ Scopus [22633]
    Коллекция содержит публикации сотрудников Казанского федерального (до 2010 года Казанского государственного) университета, проиндексированные в БД Scopus, начиная с 1970г.

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