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Title:
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Seasonal patterns of belowground biomass and productivity in mountain grasslands in the Pyrenees
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Author:
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Garcia i Pausas, Jordi; Casals, Pere; Romanyà i Socoró, Joan; Vallecillo Rodríguez, Sara; Sebastià, Ma. T.
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Notes:
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Given the importance of root dynamics for
soil C storage, the aim of this study was to analyze
first the seasonal dynamics of belowground productivity
and then the short-term effects of grazing
exclosure on root dynamics in mountain grasslands.
Soil coring and root ingrowth cores were used to
assess belowground biomass (BGB) and productivity
in grazed and ungrazed (grazing exclosures) plots in
two mountain grasslands. Annual belowground production
ranged from 472 to 590 gm−2, representing
from 14 to 22% of the maximum root biomass
measured over the year. Spring was the most
productive season, accounting for more than 50% of
total annual production, indicating that factors besides
temperature may affect seasonal root dynamics.
Although belowground production was much higher
in the top 5 cm compared to deeper, the relative
productivity rate (production-to-BGB ratio) and renewal
time was higher at the subsurface (5–15 cm)
layer. The contribution of the subsurface layer to total
belowground production increased in spring, possibly
due to occasional freezing events at the
uppermost layer in the early growing season. The
stronger seasonality in subsurface relative productivity
rates may reflect depth-dependent changes in
root characteristics and lifespan. Excluding grazing
increased belowground productivity in summer, but
its effects on BGB showed great variability
between sites.
This study was funded by the Spanish Ministry of Science and Education (MEC) within the framework of the Carbopas (REN2002-04300-C02-02) project and by the European Comission under Carbomont project (EVK1- CT-2001-00125). This research was also supported by the Balangeis project (SUM2006-0030-CO2-02), Agroeco II (CGL2009-13497-CO2-02) and the Graccie project (Consolider Nº 22422) launched by the Spanish Ministry of Science and Technology. |
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Subject(s):
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-Belowground biomass
-Grazing exclusion
-Mountain grasslands |
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Rights:
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(c) Springer Verlag, 2011
info:eu-repo/semantics/restrictedAccess |
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Document type:
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article
publishedVersion |
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Published by:
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Springer Verlag
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