Contribution of microbial activity and vegetation cover to the spatial distribution of soil respiration in mountains

Sushko, S.; Ovsepyan, L.; Gavrichkova, O.; Yevdokimov, I.; Komarova, A.; Zhuravleva, A.; Blagodatsky, S.; Kadulin, M.; Ivashchenko, K.

Авторы: Sushko Sofia, Ovsepyan Lilit, Gavrichkova Olga, Yevdokimov Ilya, Komarova Alexandra, Zhuravleva Anna, Blagodatsky Sergey, Kadulin Maxim, Ivashchenko Kristina
Журнал: Frontiers in microbiology
Год издания: 2023
Издательство: Frontiers Research Foundation
Местоположение издательства: Switzerland
DOI: 10.3389/fmicb.2023.1165045
Аннотация: The patterns of change in bioclimatic conditions determine the vegetation coverand soil properties along the altitudinal gradient. Together, these factors controlthe spatial variability of soil respiration (RS) in mountainous areas. The underlyingmechanisms, which are poorly understood, shape the resulting surface CO2 fluxin these ecosystems. We aimed to investigate the spatial variability of RS and itsdrivers on the northeastern slope of the Northwest Caucasus Mountains, Russia(1,260–2,480 m a.s.l.), in mixed, fir, and deciduous forests, as well as subalpineand alpine meadows. RS was measured simultaneously in each ecosystem at 12randomly distributed points using the closed static chamber technique. After themeasurements, topsoil samples (0–10 cm) were collected under each chamber(n = 60). Several soil physicochemical, microbial, and vegetation indices wereassessed as potential drivers of RS. We tested two hypotheses: (i) the spatialvariability of RS is higher in forests than in grasslands; and (ii) the spatial variabilityof RS in forests is mainly due to soil microbial activity, whereas in grasslands, it ismainly due to vegetation characteristics. Unexpectedly, RS variability was lower inforests than in grasslands, ranging from 1.3–6.5 versus 3.4–12.7 μmol CO2 m−1 s−1,respectively. Spatial variability of RS in forests was related to microbial functioningthrough chitinase activity (50% explained variance), whereas in grasslands it wasrelated to vegetation structure, namely graminoid abundance (27% explainedvariance). Apparently, the chitinase dependence of RS variability in forests maybe related to soil N limitation. This was confirmed by low N content and highC:N ratio compared to grassland soils. The greater sensitivity of grassland RS tovegetation structure may be related to the essential root C allocation for somegrasses. Thus, the first hypothesis concerning the higher spatial variability of RSin forests than in grasslands was not confirmed, whereas the second hypothesisconcerning the crucial role of soil microorganisms in forests and vegetation ingrasslands as drivers of RS spatial variability was confirmed.
Добавил в систему: Евдокимов Илья Витальевич

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Contribution of microbial activity and vegetation cover to the spatial distribution of soil respiration in mountainsстатья

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