内江城市防护绿地土壤抗蚀性研究"

On the Soil Anti-erodibility of the City Protective Green Belts——A Case Study of the Neijiang City

选取内江市防护绿地中林地、草地、灌丛作为研究对象.通过对土壤容重、机械组成、＞0.25mm干筛团聚体含量、抗蚀指数、水稳性指数等指标研究城市不同防护绿地对土壤抗蚀性的影响.结果表明：三种样地土壤抗蚀性都较低,其抗蚀性都随着时间的增加呈下降趋势;在机械组成中三种样地都以砂粒占主导,土壤含沙量较高;土壤干筛团聚体主要集中在2～5mm和1～2mm这两个粒径范围内,在5～7mm、1～2mm、0.5～1mm、0.25～0.5mm粒径范围内其差异不显著,在1～2mm和＞0.25mm林地和草地与灌丛的差异显著;三种样地的土壤水稳性指数变化与其抗蚀指数趋于一致,水稳性指数越高,抗蚀指数也越高.表层土壤的抗蚀性大小排列为：灌丛＞林地＞草地;亚表层土壤的抗蚀性大小排列为灌丛＞草地＞林地.

Urban green lands like the woodland, grassland, shrubland in the city ofNeijiang were chosen as our research subjects. Through the study of the indices like the volume weight, the mechanical composition, 〉0. 25mm drying sieve aggregate, the anti-erofibility index, the water stability, the effect of different protective green areas upon the anti-erodibility of city green belt soil is put under examination. The findings show that the three kinds of sampled soils are found to have a rather low anti-erodibility which decreases with time; in terms of the mechanical composition, sand grains are predominant, the sand content in soil is rather high; as for the drying sieve aggregate, the particle size range chiefly in diameter from 2mm to 5mm, and from lmm to 2mm, no significant difference is found in sand particle sizes of 5-7mm, 1-2mm, 0.5-1mm, 0. 25-0. 5mm; there exists significant difference between the woodland, the grassland and the shrubland in terms of the sand sizes ranging 1-2mm and 〉0.25mm; as for the water stability of the three sampled land soils, it goes consistent with its anti-erodibility, the higher the water stability is, the higher an erodibility will be found; the topsoil anti-erodibility of the three sampled lands is.. shrubland〉woodland〉grassland; while in terms of the anti-erodibility of the subsurface soil, the order of the three sampled soils is.. shrubland〉 grassland〉 woodland.