Annual and seasonal dynamics of
total soil respiration (TSR) of sandy Albeluvisols and clay Phaeozems under
forest, grassland, and arable were studied in situ (Russia, Moscow Region). Measurements
of soil CO2 emission were carried out by closed chamber method from
November 1997 through October 2003 weekly. The highest mean TSR (806+86
g C·m-2·yr-1) was observed for sandy Albeluvisols under
grassland. It significantly exceeded the annual CO2 fluxes from
soils of other ecosystems (P< 0.1). The lowest value of mean annual TSR was
observed for arable clay Phaeozems (361+55 g C·m-2·yr-1).
It was reliably lower than in soils of the other cenoses (P<0.5). No significant
differences were found between annual amounts of CO2 emitted from
Albeluvisols under forest and Phaeozems under forest and grassland. The interannual
variability of TSR caused by the difference of weather conditions was 30% on average and ranged
from 25-26% (forest and grassland ecosystems on Albeluvisols) to 37% (agroecosystem
on Phaeozems). We found that TSR in natural ecosystems positively correlated
with the total annual precipitation and sum of precipitation for the spring season
(R=0.73-0.90, P<0.1). The share of the cold period (November-April) to the annual
CO2 flux was substantial and averaged 22-25% and 17% for natural and
agricultural ecosystems, respectively. Therefore, emission of CO2 during the cold
period was an essential part of the annual CO2 fluxes from soils of
sub-boreal zone, which should be taken into account while calculating the
carbon budget for the whole year.
Author: V.O. Lopes de Gerenyu, I.N. Kurganova, L.N. Rozanova, et al (ikurg at issp dot psn dot ru)
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