Study On Resources Of Wild Economic Plants And Ecological Adaptation Of Representative Plants In Rocky Desertification Control Area

Karst area is rich in plant resources.As a common phenomenon of ecological degradation in karst area,rocky desertification leads to a single regional vegetation structure,ecosystem degradation and biodiversity reduction.In order to protect plant diversity and maintain the balance of ecosystem,the application of native plants in rocky desertification control was explored,so as to provide scientific basis for the development and utilization of wild economic plants and the plant configuration mode of rocky desertification control in the demonstration area.From July to November in2018 and April to October in 2019,the author carried out the plant resources survey in the Salaxi demonstration area of Bijie by using the method of combining transect and quadrat,and set up 50 quadrat sets.In August 0f 2020,the typical dominant communities were selected in the demonstration area to collect the leaves of four species——Cyclobalanopsis glaucoides,Platycarya longipes and Mahonia Imbricata,Zanthoxylum dimorphophyllum var.spinifolium,and were tested and analyzed.In order to reveal the diversity and status of plant resources in the demonstration area,the characteristics of family and genus diversity,floristic division and functional division of wild economic plant resources were analyzed;the correlation analysis and chlorophyll content analysis of leaf thickness(T),leaf length(L),leaf width(W),leaf tissue water content(LWC)and other morphological characteristics of four species in the typical ecological community in the demonstration area were carried out.In order to explore the ecological adaptability of four species in different ecological communities,the differences of physiological and biochemical indexes were analyzed,such as biomass,free proline content,soluble protein content,soluble sugar content,malondialdehyde(MDA)content,superoxide dismutase(SOD)and peroxidase(POD)activity.(1)There are 738 species of wild plants(excluding cultivated species)in the demonstration area,belonging to 439 genera of 132 families,including 16 species of13 genera of 10 families of pteridophytes,11 species of 9 genera of 7 families of gymnosperms and 709 species of 417 genera of 115 families of angiosperms.Among angiosperms,dicotyledons are the most,with 585 species belonging to 341 genera of100 families and 126 species belonging to 76 genera of 15 families.(2)Due to the interaction of karst habitat heterogeneity and human disturbance activities,the families and genera of species in the demonstration area are mainly composed of few species families and few species genera,with high diversity of families and genera,while the genera and species of seed plants tend to be concentrated in medium families and larger families,with obvious advantages of medium families and larger families,which play a dominant role in the floristic composition and community construction of the demonstration area.(3)In terms of life form,dwarf shrubs and small trees are the main woody plants,while woody vines are less,and deciduous species are far more than evergreen species.Herbaceous plants are rich and diverse,and mainly perennial,deciduous shrubs and small trees are dominant,which is not only the performance of the karst plateau ecological environment limiting the distribution of plants,but also the result of plants adapting to the karst ecological environment.(4)The flora of the demonstration area is rich,and various geographical elements are staggered and overlapped.The Pteridophyte family,genus and species differentiation is small,and the tropical component is the main component at the family level of seed plants;the temperate component is the dominant component at the genus and species level,followed by the tropical component,and there are a few Mediterranean and Central Asian components,and the Chinese endemic components account for a certain proportion,and the demonstration area has Osmunda japonica originated from Jurassic,Quercus aquilinus,Pteris pinnatifida,Lygodium japonicum and the remains of the Tertiary period are Cunninghamia lanceolata,Cryptomeria fortunei,Taxus chinensis,Podocarpus macrophyllus,and Tetracentron sinense.It can be seen that the flora origin of Salaxi demonstration area has a certain ancient relict nature,with high unique elements,complex geographical elements and wide sources,with the dual nature of temperate zone and tropical zone,and the characteristics of transition from tropical zone to temperate zone.(5)According to the classification statistics of different economic functions,there are 528 species belonging to 346 genera of 121 families,318 species belonging to 169 genera of 73 families,206 species belonging to 142 genera of 75 families,87 species belonging to 80 genera of 42 families,57 species belonging to 32 genera of 21 families,131 species belonging to 88 genera of 25 families,139 species belonging to114 genera of 63 families,19 species belonging to 14 genera of 14 families and 14 genera of resin and gum Among them,85 species belong to 62 genera of 38 families,68 species belong to 56 genera of 37 families,101 species belong to 74 genera of 46 families and 149 species belong to 123 genera of 63 families.Among the wild economic plant resources,117 kinds of Chinese medicine plants were selected for national key census;among the dominant economic plants,deciduous species mainly include Cotinus orientalis,Carpinus pubescens,Betula luminifera,Corylus yunnanensis,Quercus alba and Quercus variabilis,evergreen species include Cyclobalanopsis glauca,Cyclobalanopsis tenuifolia,Rhododendron simsii and Mahonia fortunei;rare and endangered plants include Allium latifolium,Gastrodia elata,Cymbidium faberi,Paris polyphylla var.polyphylla and Euptelea pleiosperma32 species,88 species endemic to China.The ecological environment of a single community is more fragile,and plants are more vulnerable to stress.From the perspective of morphological structure,evergreen species in the demonstration area usually protect the leaf surface by leaf coat or thick cuticle,or reduce the exposed area to reduce transpiration when adapting to karst drought and other stress,deciduous species usually choose the form of deciduous leaves to avoid the damage of stress,so as to survive the drought period smoothly.In terms of physiology and biochemistry,P.longipes,a deciduous species,is most vulnerable to stress in the community,and its biochemical indexes are relatively large,Z.dimorphophyllum var.spinifolium has the strongest drought tolerance and the strongest adaptability in different ecological communities.The drought resistance of the four species was Z.dimorphophyllum var.spinifolium > M.imbricata > C.glaucoides > P.longipes.The research shows that the wild economic plants in the demonstration area have rich diversity in plant species and economic functions,and the ecological adaptability of the species is strong,which is of great significance for the biodiversity protection and ecological and economic development of Bijie Karst Plateau.At the same time,this study provides theoretical basis and decision-making reference for the allocation and cultivation of economic plants in the demonstration area,as well as the selection and breeding of economic plants in the process of ecological environment protection and restoration and reconstruction of degraded ecosystem.However,in the future ecological restoration and reconstruction of rocky desertification control area,the basic situation and characteristics of different vegetation ecological communities and the ecological adaptability of more economic plants need to be further studied.