Study On Soil And Water Conservation Function Of Different Forest Vegetation Types Of Small Watershed Of Mianyang Guansi River

Different types of forest vegetation Guansi River as the research object,Through field investigation and laboratory analysis,chosen in the basin typically 5 forest vegetation types,broadleaf forest,mixed wood,needles pure forest,coniferous mixed forest,bamboo for the study,qualitative and quantitative analysis.By studying the lawsuit River vegetation types have different physical and chemical properties and associated soil layer after layer of litter,By studying the lawsuit River vegetation types have different physical and chemical properties and associated soil layer after layer of litter,After comprehensive analysis within the watershed areas of different soil and water conservation effect of forest vegetation type.At the same time using principal component analysis of different types of soil and water conservation forest vegetation ability to evaluate lawsuit River region,In order to improve soil and water conservation in the basin vegetation feature provides theoretical support.Through a large number of experimental data,the results show that:1) Litters of the main factors is the difference in thickness of litter composition and texture of the different sub-sources,Study area forest litter depth sorting order of bamboo (3.10cm)> mixed wood (2.99cm)> coniferous mixed forest (2.15cm)> needles pure forest (1.88cm)> broadleaf forest (1.15cm).The maximum water holding capacity of litter is mainly affected by the maximum rate and the water holding capacity of the litter,Study area maximum water holding capacity of litter changes followed bamboo (10.91 t.hm-2)> coniferous mixed forest (10.09t.hm-2)> mixed wood (9.83t.hm-2)> needles pure forest (8.09t.hm-2)> broadleaf forest (5.22 t.hm"2).Effective water-holding capacity per unit area of bamboo (8.16t.hm-2)> coniferous mixed forest (7.21 t.hm-2)> mixed wood (6.87 t.hm-2)> needles pure forest (5.28t.hm-2)> broadleaf forest (4.09t.hm-2),bamboo litter in the water absorption capacity of the strongest.2) Various types of forest vegetation at the 0-30cm soil layer thickness increases with soil depth,soil moisture content is reduced.The deeper soil layers,each forest vegetation types of soil moisture rate reached a relatively stable value. Various types of forest vegetation is manifested in soil bulk density with increasing depth into the soil layer increased.In the most vulnerable to outside interference soil bulk density coniferous 0-10cm soil layer needles pure forest (1.31g/cm3)<bamboo (1.34g/cm3)<coniferous mixed forest (1.47g/ cm3)<mixed wood (1.49g/cm3)<broadleaf forest (1.54g/cm3).3) Forest soils under different vegetation types maximum water holding capacity per unit area size were broadleaf forest (4204.00 t/hm2)> Bamboo (4088.97 t/hm2)> needles pure forest (4072.35t/hm2)> mixed wood (3691.96 t/hm2)> coniferous mixed forest (3504.46 t/hm2),Effective water-holding capacity per unit area were bamboo size (261.33 t/hm2)> needles pure forest (219.50 t/hm2)> mixed wood (199.39 t/hm2)> coniferous mixed (144.89 t/hm2)> broadleaf forest (79.60 t/hm2),Displacement size unit area were needles pure forest (1633.09 t/hm2)> broadleaf forest (1626.32 t/hm2)> coniferous mixed (1587.57 t/hm2)> mixed wood (1507.02 t/hm2)> Bamboo (1460.41 t/hm2).Overall it can be seen,bamboo water stronger.Bamboo on soil improvement mainly non-capillary porosity and more,in order to improve the performance of broad-leaved forest soil porosity and increase soil infiltration.4) Within the study area,each soil aggregate size increased with soil depth variation of the order of (> 2mm)> (2-lmm)> (1-0.5mm)> (<0.25mm)> (0.5-0.25mm).> 2mm water stable aggregates mean is needles pure forest (41.47%)> mixed wood (37.82%)> broadleaf forest (37.46%)> Bamboo (34.82%)> coniferous mixed forest (34.25%).Broadleaf forest soil aggregate water stability strongest.5) 0-20cm soil lawsuit River,20-40cm highest sand content,showed grit (2-0.02mm)> powder (0.02-0.002mm)> clay (<0.002mm),the main sandy loam.In the most vulnerable to damage soil 0-20cm soil,Size clay content were broadleaf forest> mixed wood>coniferous mixed forest> bamboo> needles pure forest.However,large differences in soil organic matter,Overall 0-20cm layer of soil organic matter content greater than 20-40cm soil layer,In the mean soil organic matter were bamboo> needles pure forest> mixed wood> coniferous mixed forest> broadleaf forest.6) Principal component analysis of the various types of soil and water conservation forest vegetation comprehensive evaluation capacity of the soil,Draw each type of forest vegetation in the study area were the strength of the soil water conservation features bamboo> needles pure forest> mixed wood>coniferous mixed forest> broadleaf forest.