Study on water physical properties and infiltration law of forest soil in northern mountain of Hebei

In order to study water physical properties and infiltration law of forest soil in northern mountain of Hebei,the soil water physical properties and soil infiltration of the mixed forest of Larix principis-rupprechtii and Betulaspp.Populus davidiana and Betula spp.,and Pinus tabulaeformis and Quercus mongolica as the research object,were measured for different forest types.the results showed that with the soil depth increase,soil bulk density gradually increased,while the soil moisture and total porosity gradually decreased.The average of soil bulk density showed the mixed forest of Pinus tabulaeformis and Quercus mongolica was maximum(1.11g/cm3),and the mixed forest of Larix principis-rupprechtii and Betulaspp.was minimum(0.92g/cm3).The descending order of maximum water holding capacity of soil was mixed forest of Populus davidiana and Betulaspp.(63.55%),mixed forest of Larix principis-rupprechtii and Betulaspp.(53.10%),mixed forest of Pinus tabulaeformis and Quercus mongolica(39.50%).The descending order of field capacity was mixed forest of Populus davidiana and Betula spp.(49.95%),mixed forest of Larix principis-rupprechtii and Betulaspp.(41.01%),mixed forest of Pinus tabulaeformis and Quercus mongolica(31.39%),The descending order of soil total porosity was mixed forest of Populus davidiana and Betula spp.(51.61%),mixed forest of Larix principis-rupprechtii and Betulaspp.(46.14%),mixed forest of Pinus tabulaeformis and Quercus mongolica(43.18%).In descending order of the soil steady infiltration rate was lower slope,middle slope,upslope for mixed forest of Larix principis-rupprechtii and Betulaspp.In descending order of the soil steady infiltration rate was middle slope,upslope,lower slope for mixed forest of Populus davidiana and Betulaspp.and mixed forest of Pinus tabulaeformis and Quercus mongolica.