Studies On Structure And Function Of Shrub Layer Of Karst Forest In Guizhou Provincial Center Mountainous Area, China

This artical takes the structure and function of the shrub layer in Guizhou provincial central karst mountainous areas as the research object.Using the methods of field plot investigation,combined with field investigation and inner analysis,qualitative and quantitative method,structure and function of the shrub layer in Guizhou provincial central karst mountainous areas was researched deeply.The data handling was carried out by computer analysis system.The main results as follows:The plant of shrub layer is rich in comprising species,complex in geographical elements, having an extensive connection with nearby floristic areas.The floristic characteristic of the region emphasizes on the tropical flora as well as the temperate flora.55 plots were divided into 15 community through the plants of shrub layer.The physiognomy of the community of shrub layer is mainly decided by the phanerophytes with microphylls,mesophylls,herbaceous, deciduous and evergreen leathery,simple and unentire leaves.In the community of shrub layer, the species diversity index,evenness index and richness index have pure correlational dependence. Gleason index is 2.7975.Menhinnick index is 0.6261.Simpson index is 0.2023.Hurlbert index is 0.8089.Shannon-Wiener index is 2.1304.Pielou index is 0.7753.The plants of shrub layer were mainly composed of Quercus fabric(8.7748),Lindera communis Hems l(4.7059),Castanea sequinii Dode(3.8524),Rhododendron simsii Planch(3.2543),Myrsine africana Linn(3.1876), Corylus heterophylla Fisch.ex Bess.var.sutchuenensis Franch(2.4199),Viburnum chinshanense Graeb(2.0879) and so on.The shrub layer coverage rate is 60%,average high is 1.65m,average DBH is 1.25era,biomass is 1.5663T/ha,leaf weight is 7.0386T/ha,and there are 32625 plants per hectare.In karst mountainous region in Guizhou provincial center,the contents of N,P,K,Ca and Mg are 17.2046Kg/hm~2,0.9289Kg/hm~2,3.8024Kg/hm~2,37.5362Kg/hm~2 and 2.686Kg/hm~2, respectively.In Pinus massoniana Lamb-Liquidambar formosana Hance,average high,DBH and leaf weight of shrub layer are least,biomas and element weight are largest.In Celtis julianae Schneid+Koelreuteria bipinnata Franch-Celtis julianae Schneid,average high and DBH of shrub layer are largest,leaf weight of shrub layer is largest in Myrica rubra(Lour.) Sieb.et Zucc+Quercus fabric-Rhododendron mariesii Hemsl.et Wils.The biomas is least in Pinus massoniana Lamb+Cunninghamia lanceolata(Lamb.) Hook+Salicaceae SP+Quercus fabric-Quercus fabric.The density and element weight are least in Liquidambar formosana Hance+Cunninghamia lanceolata(Lamb.) Hook+Pinus massoniana Lamb-Lindera communis Hemsl.The interrelation between shrub layer and the other parts of ecosystem is complicated.There are 42 families,72 genus and 106 species in tree layer.There are 67 families,148 genus and 292 species in shrub layer.There are 28 families,47 genus and 55 species in tree and shrub layer.For the average high,average DBH and biomass,the shrub layer is lower 6.5m,10.201cm and 112.0433T/ha,respectively than the tree layer.For density,the shrub layer is higher 31439(plants per hectare) than the tree layer.There are 412.6231Kg N,39.8209Kg P,264.4192Kg K, 926.0364Kg Ca,225.3816Kg Mg per ha in the tree and shrub layer,and the ratio of the shrub layer is 4.17%,2.33%,1.44%,4.05%,1.19%,respectively.For the average high,the shrub layer is higher 1.38m than the herb layer.For density,the shrub layer is lower 135748(plants per hectare) than the herb layer.There are 32.5051kg N,2.0916kg P,14.1965kg K,45.3259kg Ca,5.8252kg Mg per ha in the shrub and herb layer,and the ratio of the shrub layer is 52.92%,44.43%, 28.78%,82.81%,46.11%,respectively.The high of shrub layer and the high,DBH,density of tree layer,density,biomass of herb layer is showing a diverse change tendency.The high of shrub layer and the biomass of tree layer,high of herb is showing a similar change tendency.The DBH of shrub layer and the high,DBH,density,biomass of tree layer is showing a diverse change tendency.The density of shrub layer and the high,DBH,density,biomass of tree layer,density of herb layer is showing a similar change tendency.The density of shrub layer and the density, biomass of herb layer is showing a diverse change tendency.The biomass of shrub layer and the high,density,biomass of tree layer,density of herb layer is showing a similar change tendency. The biomass of shrub layer and the DBH of tree layer,the high,biomass of herb layer is showing a diverse change tendency.A change of the contents of elements of shrub layer and herb layer is showing a similar tendency.In karst mountainous region in Guizhou provincial center,the plants of shrub layer will grow better at middle altitude,eastern and southern slopes,under-part of less and big gradient.we can comprehend the structure and function of the shrub layer in Guizhou provincial central karst mountainous areas through the research.It provides the theory basis for vegetation restores,resource administration and vegetation protection etc.