摘要
该研究以宁夏盐池荒漠草原区苦豆子(Sophora alopecuroides)群落为研究对象,通过野外采样和实验室分析,研究了围封对苦豆子群落土壤颗粒分形维数的变化特征以及分形维数与土壤理化性质的关系。结果表明:(1)与围栏外相比,围栏处理样地的黏粒(<2μm)体积百分比含量增加,在0~10、10~20和20~40cm土层差异显著;粉粒(2~50μm)体积百分比含量在0~10cm土层显著增加;而砂粒(50~250μm)体积百分比含量减少,在0~10和10~20cm土层差异显著,围封可促使土质细粒化。(2)与围栏外相比,围栏内土壤有机碳、全N、全P、碱解氮、速效磷含量均有所提高,其中0~10cm土层分别增加了177.70%、155.70%、60.11%、120.42%、179.40%,10~20cm土层土壤有机碳、全N、全P、速效磷含量增加比例分别为202.80%、36.50%、27.78%和s37.30%,20~40cm土层土壤养分变化不显著,说明围栏封育使土壤养分主要富集在0~20cm土层,其中0~10cm土层富集达到显著水平。(3)苦豆子群落围栏内的土壤粒径分形维数在2.64~2.69之间,围栏外的分形维数在2.59~2.64之间;与围栏外相比,围栏内土壤粒径分形维数在0~10和10~20cm土层增加显著。(4)土壤粒径分形维数与土壤粒径分布、土壤有机碳、全N、全P、碱解氮、速效P含量均呈显著的线性关系,说明分形维数可以作为一个衡量土壤肥力、土壤结构以及退化土壤恢复程度的综合性指标。
In this paper, we set an object of study in the desert steppe in Ningxia, based on the field s am-pling and laboratory analysis. The characteristics of the fractal dimension of the soil and the relationship between fractal dimension and soil properties were studied. The results showed that: (1) there was more fine grained soil after enclosure. T he clay(〈2 μm)content increased significantly in 0 -10 c m , 10 - 20 cm and 20 - 40 cm soil layers(P 〈 0. 05). The silt sand(2 - 50 μm)content increased significantly in 0 - 10 cm soil layer(P 〈 0. 05). The sand(50 -250μm ) content decreased in 0 -10 c m, 10 -20 c m soil layer(P 〈 0.05). (2)Soil nutrients accumulated after enclosure. The organic carbon, TN , T P , alkali-hydrolyzablenitrogen, available phosphorus content of soil were higher. In 0 -10 cm soil layer, the organic carbon, TN, TP, alkali-hydrolyzable nitrogen, available phosphorus content increased by 177. 70%, 155. 70%, 60.11%, 120. 42% , and 179. 40% , respectively. In 10 -20 cm soil layer, the soil organic carbon, T N , TP, available phosphorus content increased by 202. 80 %, 36. 50%, 27. 78 % and 37. 30 % , respectively. The soil nutrient change is not significant in 20 -40 cm soil layer(P〉0. 05). Obviously, enriched nutri-ents were distributed mainly in the 0 -20 cm layer and concentrated in 0 -10 cm layer(P〈0 . 05). (3 ) In the enclosed plot, the fractal dimension of soil is of between 2. 64 - 2. 69, and the fractal dimension of the out-side fence is 2. 59 - 2. 64. Compared with outside fence, the fractal dimension of soil in the enclosed plot increased significantly in 0 -10 cm and 10 -20 cm(P〈0 . 05). (4 )T h e soil fractal dimension and soil pa r t i-cle size distribution, the organic carbon, TN, TP, alkali-hydrolyzable nitrogen, available phosphorus con-tent all showed a linear relationship. The results show that fractal dimension can be used as a comprehen-sive index to measure soil fertility, soil structure and soil restoration.
出处
《西北植物学报》
CAS
CSCD
北大核心
2017年第6期1234-1241,共8页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金(31540007)
关键词
苦豆子群落
荒漠草原
封育
分形维数
土壤理化性质
Sophora alopecuroides community
desert s tep p e
fencing
fractal dimension
soil physico-chemical properties