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通过实验室培养的方法,研究了沙坡头地区不同植被配置区(纯柠条、纯油蒿、柠条油蒿混交林)土壤碳矿化潜力及不同凋落物在土壤中的分解。结果表明,通过103d的室内培养,相同配置不同处理的土壤碳矿化差异不显著,灌丛密度高的植被配置碳矿化量高。不同生境土壤CO2-C的释放在灌丛下不加凋落物处理的情况下,单行油蒿与双行柠条样地间碳矿化存在显著性差异(P=0.047),其他各样地及各处理差异均不显著。总的来说,柠条样地土壤碳矿化潜力高于其他2种样地。凋落物分解速率在不同生境土壤最初的分解速率均为1年生草本混合样>油蒿>柠条,在培养40d之后,3种凋落物的分解速率趋于一致,这与草本较高的C、N、C/N比有关。另外,柠条样地的土壤加油蒿凋落物比在柠条样地的土壤中加柠条凋落物有较高的初始碳矿化潜力,这除与油蒿凋落物较易分解有关外还与不同生境土壤养分的可利用性有关,但在培养过程中出现拐点,这与柠条较高的C、N、C/N有关。在不同生境的土壤中,碳矿化潜力均为灌丛下>灌丛外,灌木的存在使更多的有机质和养分积聚在灌丛下,形成灌丛肥岛,对碳的固存具有显著贡献。
The potential of carbon mineralization and the decomposition of different litter in soils with different vegetation allocation zones (pure Carambola, pure Artemisia ordosica, Artemisia mandshurica mixed forest) in Shapotou area were studied by laboratory culture. The results showed that there was no significant difference in soil carbon mineralization with different treatments under the same configuration through 103 days of in-house culture, and the vegetation density with high shrub density was high with carbon mineralization. Soil CO2-C release from different habitats was not significantly affected by litterfall treatment (P = 0.047), but the differences were not significant There was no significant difference among treatments. In general, the soil potential for mineralization of Caragana korshinskii is higher than the other two sites. The decomposition rate of litter in different habitats was first year herbaceous hybrid> Artemisia ordosica> Caragana korshinskii. After 40 days of culture, the decomposition rates of the three litters tended to be the same, N, C / N ratio. In addition, the Caragana korshinskii soil Artemisia ordosica litter had higher initial carbon mineralization potential than the Caragana littoralis litter in the soil of Caragana korshinskii, which was not only related to the easier decomposition of the Artemisia ordosica litter, The availability of soil nutrients in different habitats, but inflection point appeared in the culture process, which is related to the higher C, N, C / N of Caragana korshinskii. In soils with different habitats, the potential for carbon mineralization is under shrubs> shrubs. The presence of shrubs accumulates more organic matter and nutrients under shrubs and forms shrubs and fertile islands with significant carbon fixation contribution.