Study On Chemical Characteristics Of Plant-Soil Ecology In Different Succession Stages Of Caohai Wetland In Guizhou Province

Under the influence of natural and man-made two factors,grassland wetland vegetation is leading to the direction of swamp,and the water body has different degrees of eutrophication.Lake eutrophication and its depletion of submerged macrophytes,aquatic plant diversity and other issues have become a worldwide problem.Ecological stoichiometry is a discipline that studies the element flow and balance between plant and natural environment.Therefore,the use of ecological stoichiometry method to reveal the plateau lakes eutrophication effects on aquatic plants and marsh wetland vegetation prediction trend for wetland protection and has important theoretical significance to the restoration and reconstruction work,and has positive significance for the enrichment and development of wetland ecosystem in China in ecological stoichiometry chemometrics.In this paper,we used the spatial distribution instead of the time course to study the plant communities with different successional stages of grassland wetland as the object.Through the field investigation of aquatic plant community,combined with the indoor analysis of the sample,analysising of driving factors of water quality variation in Grass Sea and its effects on aquatic plant communities by Principal Component Analysis and Quantity Sorting.The changes of plant-soil eco-chemical metrological characteristics of different successional stages of grassland wetland were studied by eco-stoichiometric method.The adaptability mechanism of plant in water eutrophication environment and the comparison of different successional stages Inter-plant stability difference.The main conclusions are as follows:1)Characteristics of ?-diversity of aquatic plants in eutrophic zoning of grasses:In general,mild eutrophication grade(B area)>middle of the nutritional level(C area)>moderate eutrophication grade(A area);different succession stage plant community ? diversity changes:Simpson diversity index(D),Pielou evenness index(J)little change;The abundance index(R): 1> II> IV> III;Shannon-Wiener information index(H)1> IV> II> III;The main factors of water quality factor analysis showed that the main eutrophic factors were total nitrogen,total phosphorus,permanganate index,dissolved oxygen,leaf green a content and transparency;2)Redundancy analysis(RDA)indicated that total nitrogen,total phosphorus,chlorophyll a content and potassium permanganate index were the main environmental factors affecting the distribution of aquatic plants,Among them,Lemna minor,Alternanthera philoxeroides,Potamogeton natans,Scirpus triqueter L and Schoenoplectus tabernaemontani were mixed with total nitrogen,total phosphorus and chlorophyll a The results showed that these species had good adaptability to eutrophication,hi-rich habitat.The waterlogging plants such as Hydrilla verticillata,Potamogeton perfoliatus and Ottelia acuminata were negatively correlated with pollution factors.These plants were mainly found in the middle reaches of the region,prefering more clean water bodies;3)With the process of positive succession sequence,the C content of dominant species in plant community gradually increased,and the ability of vegetation C was gradually enhanced with the process of forward succession.Indicating that grassland vegetation is mainly restricted by P element;In general,with the succession sequence,soil C,N,P element content,measurement ratio and active ingredient showed a decreasing trend as a whole,which is a sign of soil degradation(swamp);4)The internal stability of different elements in the grassland wetland plants is HN: P>HN>HP,the range of HN is-1.57-12.35,the range of HP is-0.48-1.109,the variation range of HN: P is-1.04-14.29.The plant density of the plants with high chemical stability can survive in the eutrophic lakes with the increase of the degree of eutrophication of the lake.The succession of the plants is only Community associated species or no record,is now becoming the dominant species of the community of such plants have a high stability.5)Potassogeton malaianus,Potamogeton lucens and Utricularia Aurea Lour in submerged plants have higher C: N and C:P ratios,and these plants may be more Suitable for the grassland wetland eutrophic lake submerged plant restoration species.