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Titel |
Microtopographic variation in soil respiration and its controlling factors vary with plant phenophases in a desert–shrub ecosystem |
VerfasserIn |
B. Wang, T. S. Zha, X. Jia, J. N. Gong, B. Wu, C. P. A. Bourque, Y. Zhang, S. G. Qin, G. P. Chen, H. Peltola |
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 ; 12, no. 19 ; Nr. 12, no. 19 (2015-10-08), S.5705-5714 |
Datensatznummer |
250118116
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Publikation (Nr.) |
copernicus.org/bg-12-5705-2015.pdf |
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Zusammenfassung |
Soil respiration (Rs) and its biophysical controls were measured
over a fixed sand dune in a desert–shrub ecosystem in northwest China in 2012
to explore the mechanisms controlling the spatial heterogeneity in
Rs and to understand the plant effects on the spatial variation
in Rs in different phenophases. The measurements were carried out
on four slope orientations (i.e., windward, leeward, north- and south-facing)
and three height positions on each slope (i.e., lower, upper, and top) across
the phenophases of the dominant shrub species (Artemisia ordosica).
Coefficient of variation (i.e., standard deviation/mean) of Rs
across the 11 microsites over our measurement period was 23.5 %. Soil
respiration was highest on the leeward slope, and lowest on the windward
slope. Over the measurement period, plant-related factors, rather than
microhydrometeorological factors, affected the microtopographic variation
in Rs. During the flower-bearing phase, root biomass affected
Rs most, explaining 72 % of the total variation. During the
leaf coloration–defoliation phase, soil nitrogen content affected
Rs the most, explaining 56 % of the total variation. Our
findings highlight that spatial pattern in Rs was dependent on
plant distribution over a desert sand dune, and plant-related factors largely
regulated topographic variation in Rs, and such regulations
varied with plant phenology. |
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