Dalbergia Odorifera Forest Associated Species Adaptability Evaluation And Compound Management Research

Understory vegetation is a special part of Dalbergia odorifera forest,which is of important significance to maintain forest system stability and to improve the site growth.Used the gray correlation degree analysis we indexed the adaptability of associated vegetation under the D.odorifera plantation in Chengmai,and we designed 4 models of undergrowth compound management,that are medicine model,agro forestry model,herbage model and fertilizer model.Followed up the managements on the varies models,we analyzed the soil nutrient improvements,the undergrowth community changes and the forest growth effects in different models,aimed at providing theoretical references for the compound management of D.odorifera forest.1.There are 86 species,belonging to 41 families and 79 genera of D.odorifera undergrowth.From the perspective of plant type,the species and quantity of the angiosperm are dominant,while the species of fern are few and quantities are many.The dominant families are obvious.For example,there are many kind of species like Euphorbiaceae,Leguminosae,Rubiaceae,Gramineae,Compositae,etc.In the survey sample,Crassocephalum crepidioides has the highest important value about 86.21.so as the Ageratum conyzoides,Dracaena angustifoli and Piper sarmentosum,all above 50.00.Manihot esculenta,Solarium nigrum,Uraria lagopodioides and Medicago sativa are below 15.00,as the occasional species.The important value of Ipomoea batatas below 10,which belongs to extinction.2.Adaptability evaluation of D.odorifera forest understory companion species and construction of compound managements.The study use the method of grey correlation analysis,from 3 aspects such as growth properties,system structure and function effects,to appraise the influence factors of D.odorifera main forest associated species adaptability.We chose 15 indexes,which contain height,survival rate,coverage,et al,to construct the index system for Adaptability evaluation of D.odorifera understory companion species,and at last got an adaptive ranking.The best adaptive plants are Arachis hypogaea,Desmodium triflorum,Alysicarpus vaginalis,Stephania epigaea,Lolium perenne,of which the correlations are 0.9613?0.9591?0.9562?0.9486?0.9412.The correlations of Dracaena angustifolia,Millettia speciosa,Piper sarmentosum,Desmodium reticulatum,Manihot esculenta,Ageratum conyzoides,Arachis hypogaea,Richardia scabra,Borreria stricta have passed 8.The general adaptive plant contain Clerodendrum cyrtophyllum,Clerodendrum cyrtophyllum,Trifolium repens,Crotalaria uncinella,Crotalaria uncinella,Crotalaria uncinella,of which the correlations are 7.914?7.743?7.392?7.259?7.182.Besides,the correlations of other plants are less than 7.Accord to the ranking,we ehose Stephania epigaea,Indigofera hirsute,Arachis hypogaea,Trifolium repens,Clerodendrum cyrtophyllum,Lolium perenne to design 4 management models,that are S.epigaea for the medicine model;A.hypogaea for the agro forestry model;C.cyrtophyllum+Lolium perenne for the herbage model and Indigofera hirsute+T.repens for the fertilizer model.3.Effects of forest compound management models on the forestry growth.The designed models had promotion effect on growth of D.odorifera.The fertilizer model worked best,and the average height and diameter at breast heigh(DBH)of trees in sample plot had increased by 2.71m and 2.53m.Compared with the control plot,the growth rate of average height and DBH of trees in fertilizer model plot had increased by 26%and 22%.At the same time the growth rate of average height and DBH of trees in other 3 models' plots were also higher than the control plot.4.There are 56 species plants of forests composite sample area of operation,the species of the Gamineae and Rubiaceae are dominant,while the species which includes more are few.The total number of species of forest plots Medicine Model,foresters mode,mode and phosphate mode grass were 20,18,21,24,they were higher than the control plot 17.The main construction of artificial forest associated species occupies a major niche in the community,important values above 50.00.The important value of original advantages plant includes C.crepidioides,A.conyzoides,D.angustifolia and P.sarmentos,um were 36.21,34.85,29.63 and 34.93,which decreased by 58.01%,58.35%,61.83%and 52.39%.The average tree height and average DBH of fertilizer model within the sample area dalbergiae cocobolo increased by 2.71 m and 2.53 cm respectively.And compared to the control plot,tree high growth rate and DBH growth rate of fertilizer model increased by 26%and 22%,respectively,high tree diameter at breast height growth rate of herbage model increased by 16%and 18%respectively,tree height and diameter at breast height growth rate of medicine model.agro forestry model are higher than the control plot and are at around 10%.