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Titel |
Soil organic carbon dynamics of black locust plantations in the middle Loess Plateau area of China |
VerfasserIn |
N. Lu, J. Liski, R. Y. Chang, A. Akujärvi, X. Wu, T. T. Jin, Y. F. Wang, B. J. Fu |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 11 ; Nr. 10, no. 11 (2013-11-07), S.7053-7063 |
Datensatznummer |
250085399
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Publikation (Nr.) |
copernicus.org/bg-10-7053-2013.pdf |
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Zusammenfassung |
Soil organic carbon (SOC) is the largest terrestrial carbon pool and
sensitive to land use and cover change; its dynamics are critical for carbon
cycling in terrestrial ecosystems and the atmosphere. In this study, we
combined a modeling approach and field measurements to examine the temporal
dynamics of SOC following afforestation (Robinia pseudoacacia) of former arable land at six
sites under different climatic conditions in the Loess Plateau during
1980–2010, where the annual mean precipitation ranging from 450 mm to 600 mm. The
results showed that the measured mean SOC increased to levels higher than
before afforestation when taking the last measurements (i.e., at age 25 to
30 yr) at all the sites, although it decreased at the wetter sites in the
first few years. The accumulation rates of SOC were 1.58 to 6.22% yr−1
in the upper 20 cm and 1.62 to 5.15% yr−1in the upper
40 cm of soil. The simulations reproduced the basic characteristics of
measured SOC dynamics, suggesting that litter input and climatic factors
(temperature and precipitation) were the major causes for SOC dynamics and
the differences among the sites. They explained 88–96, 48–86 and 57–74%
of the variations in annual SOC changes at the soil depths of 0–20, 0–40,
and 0–100 cm, respectively. Notably, the simulated SOC decreased during the
first few years at all the sites, although the magnitudes of decreases were
smaller at the drier sites. This suggested that the modeling may be
advantageous in capturing SOC changes at finer timescale. The discrepancy
between the simulation and measurement was a result of uncertainties in
model structure, data input, and sampling design. Our findings indicated
that afforestation promoted soil carbon sequestration at the study sites
during 1980–2010. Afforestation activities should decrease soil disturbances
to reduce carbon release in the early stage. The long-term strategy for
carbon fixation capability of the plantations should also consider the
climate and site conditions, species adaptability, and successional stage of
recovery. |
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