Eco-stoichiometric Characteristics Of Plant-soil Carbon,Nitrogen And Phosphorus In Typical Plant Communities In Chaohu Wetland

Wetlands are known as the "kidney of the earth".With the gradual recognition of the importance of wetlands,wetland research has become a hot topic in recent years.The contents of soil,plant carbon,nitrogen,phosphorus and ecologic stoichiometric characteristics of Chaohu Lake wetland were studied in order to provide a basis for the ecological protection and restoration of Chaohu Lake wetland.In Chaohu Lake wetland as the research object,using five kinds of typical plant community: cattail community(Typha orientalis),reed(Phragmites australis),wild pond artemisia community(Conyza bonariensis),solidago canadensis community(Solidago decurrens),red smartweed community(Polygonum orientale),the sample survey method is adopted,plants and soil samples,the analysis of the wetland soil and plant nutrient content and characteristics of ecological stoichiometry,explore the wetland soil-plant ecological stoichiometry between the correlation between characteristics,soil physical and chemical properties of soil and plant ecological characteristics of chemometrics.The main conclusions are as follows:(1)The average soil carbon,nitrogen and phosphorus contents of five plant communities were different in different seasons.In the dormancy season,the soil organic carbon(8.88 g/kg)and total nitrogen content(1.16 g/kg)were the highest in the goldenseal community,the soil total phosphorus content was the highest in the cattail community community(0.38 g/kg),and the variation range of total phosphorus was the largest,25.41%?63.53%.In the growing season,soil organic carbon(11.01 g/kg),total nitrogen(1.78 g/kg)and total phosphorus(0.35 g/kg)were the highest in cattail community,and the variation degree of soil organic carbon ranged from 9.57% to 83.82%.The nutrient content was higher in the growing season than in the dormant season.In the growing season,the carbon and nitrogen in wetland soil had obvious surface accumulation,and the change of soil carbon and nitrogen was consistent between soil layers,and there is a large variability between soil layers.However,there was no significant difference between soil layers of total phosphorus(P > 0.05),and the surface accumulation was not obvious.Soil stoichiometry was different between seasons.The soil C:N,C:P and N:P basically showed a different change with the increase of soil sampling depth,that is,decrease with the increase of depth.The wetland soil C:N in the survey area was between 4.07 and 11.54,which was lower than that for the Chinese wetland soil C:N(18.22);the lower C:N ratio indicated that the soil organic matter decomposed faster and forms less humus;the soil C:P was lower than wetland soil C:P in China(245.22);and soil N:P was slao lower than the China wetland soil N:P(13.60),indicating that the nitrogen content was low.(2)The average carbon,nitrogen and phosphorus contents of the dominant species in the five plant communities were different in different seasons.The carbon content of the dominant species in the five plant communities was higher in the growth season than in the dormant season,and the difference in nitrogen and phosphorus contents of the dominant species was significant(P < 0.05),with a low degree of variation.The stoichiometric ratios of C,N and P of plants in each community were all C:P > C:N > N:P.Phytostoichiometry was different in different seasons.In both dormancy and growth seasons,the plant C:P was the highest in cattail community and the lowest in polygonum.(3)Based on the analysis of plant-soil correlation,it was found that plant C:N,C:P and N:P had no correlation with soil C:N,C:P and N:P.Plant C,N and P are correlated with the corresponding C,N and P in soil,indicating that soil nutrient supply affects the nutrient content of plant tissues,and the nutrient for plant growth mainly comes from soil.(4)The experimental results showed that soil pH,water content and bulk density were the main factors affecting soil nutrient and ecological stoichiometric characteristics.Soil pH and water content had little effect on plant nutrients,while bulk density had no effect on plant nutrients.The correlation between soil carbon,nitrogen and phosphorus and its ecological stoichiometric ratio showed that C,N and P were significantly positively correlated,N and C:P were significantly positively correlated(P < 0.01),and C:P were significantly positively correlated with C:N and N:P(P < 0.01).