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在野外调查与室内分析的基础上,对黄土丘陵区典型草原带植被自然恢复过程中土壤水稳性团聚体及其主要影响因子的演变规律进行了研究,并用通径分析法对二者的相互关系进行了定量分析。结果表明:随着植被演替,土壤中大粒级水稳性团聚体含量逐步增加,>5mm粒级团聚体在土壤团粒结构中占主导地位,含量占50%~80%。其次是5~2mm含量,占到10%~15%左右。不同群落之间>5mm团聚体含量在2m深土层加权平均值比较结果为:大羽茅群落>长芒草群落>铁杆蒿群落>百里香群落>香茅草群落,其中大羽茅群落是香茅草群落>5mm团聚体含量的近5倍,长芒草群落也是香茅草群落的近4倍左右。主要影响因子对团聚体直接作用系数的大小为:物理性粘粒>有机质>全氮>全铁>阳离子交换量>全量铝>游离铁>全磷>pH值>粘粒>碳酸钙。物理性粘粒、有机质和全氮是影响水稳性团聚体含量的主要因子。
Based on field investigation and laboratory analysis, the evolution of soil water-stable aggregates and their main influencing factors during the natural restoration of vegetation in the typical steppe vegetation in the loess hilly region was studied, and the relationship between the two The relationship was quantitatively analyzed. The results showed that with the succession of vegetation, the content of large-sized water-stable aggregates increased gradually, and the aggregates> 5 mm aggregates dominated the soil aggregate structure, accounting for 50% ~ 80% of the total soil aggregates. Followed by 5 ~ 2mm content, accounting for about 10% to 15%. The results showed that:> 5 mm soil aggregates> 5 mm soil aggregates> 2 mm deep soil layers, the results were as follows: Dahomeyx obscurus community> Amomumvollina community> Artemisia tatarinoff community> Thyme community> Lemongrass community, Aggregate content of nearly 5 times, Chang Meng grass community is also citron grass community nearly 4 times. The main influencing factors on aggregates direct acting coefficient of the size: physical clay> organic matter> total nitrogen> total iron> cation exchange capacity> total aluminum> free iron> total phosphorus> pH> clay> calcium carbonate. Physical clay, organic matter and total nitrogen are the main factors affecting the content of water-stable aggregates.