不同林龄马尾松人工林土壤水土保持功能

Soil and Water Conservation Functions of Pinus massoniana Plantation at Different Forest Ages

以宜宾高县5个林龄马尾松人工林为对象,对林地土壤持水性、团聚体水稳定性及抗蚀性进行研究。结果表明：土壤容重随林龄增长先增加后减小,中龄林最大,表层和亚表层分别为1.293g/cm3,1.448g/cm3,与总孔隙度、毛管孔隙度呈极显著负相关;林龄对土壤肥力作用显著,中龄林及近熟林养分低于其他林龄;林地以DR0.5、DR0.25为主,含量为51.910%-85.770%,63.334%-86.780%;

The water retention, water stability of soil aggregates, soil anti-erodibility in 5 different forest ages Pinus massoniana plantations were examined in Gao county, Sichuan province, China. The results showed that soil bulk density increased firstly, then decreased with increasing forest age. Soil density in mid-maturation plantation was the highest（1. 293 g/cm^3 in surface, 1. 448 g/cm^3 in subsurface）, and it had a highly significant negative correlation with soil total porosity and capillary porosity. Forest age had a significantly impact on soil nutrient, the nutrients of mid-and near-maturation plantation were lower than that of the others. The main soil aggregates was DR0.5 and DR0.25, which ranged from 51. 910% to 85. 770%, from 63. 334% to 86. 780% respectively. PAD of Pinus massoniana plantation at different forest ages was M40〈Ma〈M3〈M31〈M14 , soil aggregate of mid-maturation plantation decreased, which was easy to cause serious soil erosion. The order of average soil erodibility factor（K） values of 0-40 cm soil layer was M40〈Ms〈MI4〈M31〈Ma, and it was very significant negative correlation with clay and organic matter, very significant positive correlation with silt. Soil texture determined soil erodibility. Soil organic matter content and soil particle composition of forest were main factors influencing soil erodibility, and had an impact on soil aeration conditions, to a certain extent, determined the soil adhesion and water-holding ability. The soil texture of mid-and near-maturation plantation deteriorated, soil aggregates decreased, water-holding ability reduced, thus reconstructing of low-function forest especiallyis for mid- and near-maturation forest was very important.