Kazan Federal University Digital Repository

Depth rather than microrelief controls microbial biomass and kinetics of C-, N-, P- and S-cycle enzymes in peatland

Show simple item record

dc.contributor.author Parvin S.
dc.contributor.author Blagodatskaya E.
dc.contributor.author Becker J.
dc.contributor.author Kuzyakov Y.
dc.contributor.author Uddin S.
dc.contributor.author Dorodnikov M.
dc.date.accessioned 2019-01-22T20:32:27Z
dc.date.available 2019-01-22T20:32:27Z
dc.date.issued 2018
dc.identifier.issn 0016-7061
dc.identifier.uri https://dspace.kpfu.ru/xmlui/handle/net/147624
dc.description.abstract © 2018 Elsevier B.V. The formation of microrelief forms in peatlands - elevated and dry hummocks, depressed wet hollows and intermediate lawns - is controlled by the interaction of water table, nutrient availability and dominant plant communities. This affects the composition and activity of various functional groups of microorganisms. With depth, the change in peat quality from less to more highly processed organic material additionally regulates microbial activity. We hypothesized that microbial biomass and enzyme activities are driven by aeration and by peat quality and therefore (i) they increase from hollows (water saturated/anaerobic) through lawns (intermediate) to hummocks (aerobic) in the top peat and ii) they decrease with depth due to increasing distance from fresh plant-derived inputs and lower oxygen availability. These hypotheses were tested for enzymes catalysing the decomposition of C-, N-, P- and S-containing organic compounds in peat of the three microform types at three depths (15, 50 and 200 cm). Microbial biomass and peat chemical characteristics were compared with enzyme kinetic parameters, i.e. maximal potential activity (Vmax) and the Michaelis constant (Km). Microbial biomass carbon (MBC) and Vmax of β-glucosidase and N-acetyl glucosaminidase increased by 30–70% from hummocks and lawns to hollows in the top 15 cm, contradicting the hypothesis. Similarly, Km and the catalytic efficiency of enzymes (Ka = Vmax/Km) were best related to MBC distribution and not to the aeration gradient. With depth, Vmax of β-glucosidase, xylosidase and leucine aminopeptidase followed the hypothesized pattern in hollows. In contrast, MBC was 1.3–4 times higher at 50 cm, followed by successively lower contents at 15 and 200 cm in all microforms. The same depth pattern characterized the Vmax distribution of 6 out of 8 enzymes. Phosphatase activity decreased from drier hummock to wetter hollows and the higher activity throughout the peat profile suggested a high microbial demand for P. Enzyme activities and catalytic efficiency in peat were closely linked to the distribution of microbial biomass with depth, which in turn was best explained by P content. From the ecological perspective, these results clearly show that peat decomposition will be accelerated when microbial activity is stimulated e.g. by increased P availability.
dc.relation.ispartofseries Geoderma
dc.subject Enzyme catalytic efficiency
dc.subject Microbial biomass carbon
dc.subject P limitation
dc.subject Peat profile
dc.subject Peatland microforms
dc.title Depth rather than microrelief controls microbial biomass and kinetics of C-, N-, P- and S-cycle enzymes in peatland
dc.type Article
dc.relation.ispartofseries-volume 324
dc.collection Публикации сотрудников КФУ
dc.relation.startpage 67
dc.source.id SCOPUS00167061-2018-324-SID85044163766


Files in this item

This item appears in the following Collection(s)

  • Публикации сотрудников КФУ Scopus [24551]
    Коллекция содержит публикации сотрудников Казанского федерального (до 2010 года Казанского государственного) университета, проиндексированные в БД Scopus, начиная с 1970г.

Show simple item record

Search DSpace


Advanced Search

Browse

My Account

Statistics