The Macroporosity Properties of Forest Soil and Its Eco-hydrological Significance

The macropore is a common phenomena to forest soil with notable influence to water transport in soil.The standard of macropore size has not been unified due to the differences among the research methodology and purposes.The macropore aperture was usually considered as 0.03～3 mm.The pore of aperture larger than 3mm,which was very massive comparison with soil pore structure,was not concluded in soil macropre because of water transport form in these pores being different from normal soils.The activities of animals and function of roots were main causes of macropore formation for forest soil.The methodologies of macropore research had dye tracer,CT scanning and infiltration,and the fractal theory was also used to researched macropore characters.The most characteristic of macropore was water movement rapidly,So the two-region model was used widely,which the soil pores were divided into two parts,one part water moved rapidly and the other part water moved very slowly.The surface flow was principle formation for forestry adjusting runoff and conserving water,and the soil macropre significantly affected the surface flow formed.The study about forest soil macropore could further understand the mechanism of forest conserving water and the process of forest adjusting runoff.