Study On Mechanism And Management Models For Water Resources Conservation Forests In Middle Segment Of Daqing Mountains

Daqing Mountain is the main body of Yinshan Mountains, located in the northern of Tumochuan Plains, irrigated farmland of Tumochuan Plains in the south of Daqing Mountain. This area is located in the upper and middle reaches of the Yellow River, carry out 236,900,000 m~3 water to Yellow River each year. Therefore, Daqing Mountain is an important source of water supply areas in the upper and middle reaches of the Yellow River, and plays an important role of regulation water balance and water supply. In this paper, Guluban Farmland was typical research objector in the middle of Daqing Mountain, measured data as the main body and combination of information gathered, analyzed community structure of water conservation forest, soil structure, function of forest microclimate, water conservation function, and put forward recommendation to manage water conservation forest. In order to in-depth knowledge of mechanism of hydrological of vegetation in the area, and provided method for management of water conservation forest.The main results are as follows:(1) Community structure of forestsThe density of 30a pinus tabulaeformis plantation should not be more than 3200 / hm2 in Daqing Mountain, the density of 20a larix prince rupprecht plantation in 1700 / hm2 without differentiation phenomenon.Neighborhood comparison shows pinus tabulaeformis plantation's diameter comparison is the biggest, Larix prince rupprecht and Btula platyphlla's height comparison are biggest, Larix prince rupprecht's crown comparison is largest. Uniform angle index indicated that pinus tabulaeformis and Larix prince rupprecht are uniformly distribution, Btula platyphlla is random distribution. Point pattern analysis shows pinus tabulaeformis in the scale of 3-43m is gathered distribution, Larix prince rupprecht in the scale of r>2m is random distribution, Btula platyphlla in the scale of 2-50m is significant gathered distribution.(2) Physical and chemical properties of forest soilSoil bulk densities of Btula platyphlla and larix prince rupprecht are significant better than other vegetation type in Daqing Mountain. In total porosity, Btula platyphlla and larix prince rupprecht are more than 50%, the performance of pinus tabulaeformis is worst.In an average soil bulk density, total porosity, capillary porosity, the largest water holding capacity of soil, capillary water holding capacity, field capacity, followed by Btula platyphlla > larix prince rupprecht >Ostryopsis Decne> pinus tabulaeformis.The content of surface soil organic of Btula platyphlla and larix prince rupprecht is higher than others, with the increase in the depth of soil, the content of soil organic decreased in all types. Btula platyphlla's total N content of surface soil is the biggest, which is 0.658%; Ostryopsis Decne's is the smallest, which is 0.326%. When soil depth reaches 40-60cm, Btula platyphlla's total N content is largest, which is 0.162%, pinus tabulaeformis's is the smallest, which is 0.084%. The content of surface soil total P is pinus tabulaeformis 0.108%, larix prince rupprecht 0.112%, Btula platyphlla 0.116%, Ostryopsis Decne 0.110%, when soil depth reaches 20-40cm, the content of larix prince rupprecht is higher than surface. It indicates the total P is not evenly distributed. The C/N ration of different soil in different vegetation changes largely, in 0-10cm layer, pinus tabulaeformis's ration is biggest, Btula platyphlla's ration is smallest, but in 40-60cm layer, larix prince rupprecht's ration is biggest, Ostryopsis Decne's ration is smallest.The largest radius scope of macropores in different vegetation is distributed in 1.5-1.8mm; the smallest is concentrated in 0.6-0.8mm. The density of macropores shows that large radius macropores with small density, small radius macropores with large density. The density of macropores in different depth shows that upper soil with relatively small density, the lower soil with relatively large density. The macropores in different vegetation follow the order: Ostryopsis Decne (1.09mm)> pinus tabulaeformis (0.92mm) >Btula platyphlla (0.90mm)> larix prince rupprecht (0.87mm). The density of macropores in the range of 90-587/dm~2, the average is 258/dm~2; the coefficient of variation is 62.59%. Simulated density and average radius of macropores with power function, the correlation coefficient R~2 is 0.892. On the basis of research, the macropores maybe obviously effect by biological and physical factors.(3) Characteristics of forest micro-climateInner temperature of pinus tabulaeformis is low 0.03℃than outside, inner humidity is high 0.58% than outside, inner wind speed is small 1.69m/s than outside; inner temperature of larix prince rupprecht is low 0.54℃than outside, inner humidity is low 0.05% than outside, inner wind speed is small 0.54m/s than outside; inner temperature of Btula platyphlla is low 0.05℃than outside, inner humidity is high 0.99% than outside, inner wind speed is small 0.42m/s than outside; Characteristics of different stand shows, inner temperature of pinus tabulaeformis, and inner humidity of Btula platyphlla and inner wind speed of larix prince rupprecht are biggest.(4) Ecological functions of water conservation forestCanopy interception has close relationship with rainfall levels, with increase of rainfall, interception ability of canopy lower. When rainfall is 20mm, interception rate of canopy was only 5.21-19.92%. The biggest interception ability shows, pinus tabulaeformis's interception is large to 0.170mm, larix prince rupprecht and Btula platyphlla are 0.104mm and 0.052mm.The volume of forest litters shows, pinus tabulaeformis is smallest to 5.15t/hm~2; larix prince rupprecht is biggest to 18.62t/hm~2. The water-holding capacity indicates, larix prince rupprecht is 0.65mm, pinus tabulaeformis is only0.11mm. Processes of water-holding capacity shows, in the first half an hour, Btula platyphlla absorbs large of water to 1.81g/g, pinus tabulaeformis only absorbs 0.70g/g, which is 38.67% of Btula platyphlla. With the increase of time, 4 types of litters' water-holding volume is increase, but speed is slow.Penetration characteristics changes great in different vegetation, the penetration of Btula platyphlla and larix prince rupprecht is good. In small intensity (intensity of rainfall