Study On Alpine Meadow Community And Its Ecological Stoichiometry In Sejila Mountain

In the system where plants and soil are interconnected,soil has fertility and provides water and mineral nutrients for the growth and development of plants.The texture,water and mineral nutrient content of soil not only affect the individual development of plants,but also the type,distribution and dynamics of plant communities.One of the decisive factors.The ecological effects of plants on the soil are due to factors such as the utilization of soil fertility,the fixation of the soil,the accumulation and decomposition of plant community biomass,etc.,which make the soil nutrients appear various dynamic changes in time and space scales..Therefore,the effect of soil nutrients is inseparable from the diversity and productivity of plant communities,and the relationship between the two has always been an important research object of researchers.This interactive effect relationship will vary with different environments,and topographic factors are an important factor in the relationship between vegetation and soil.Mountain ecosystems are one of the important components of terrestrial ecosystems,and alpine meadow ecosystems are part of alpine mountain ecosystems.Alpine meadow vegetation is closely related to soil and sensitive to climate change.It is the interaction between alpine ecosystem vegetation and soil.An important part of impact research.Sejila Mountain is located in an alpine region,with a large altitude span,obvious vertical differentiation of vegetation and soil,and the distribution of east and west slopes is basically even.It is a typical area where the interaction effects of vegetation and soil under the influence of slope can be studied.The alpine meadow vegetation of Sejila Mountain belongs to an important vegetation zone spectrum in Sejila Mountain.It is not only an important part of the vegetation of Sejila Mountain,but also an important grazing area for local herders in summer.The diversity of meadow plants in this area And the research on soil nutrient conditions are rarely reported.Under such circumstances,this paper studies the interrelationship between the plant community characteristics of the alpine meadow in Sejila Mountain and its soil factors,and draws the following conclusions:(1)53 species of seed plants were investigated in the alpine meadow of Sejila Mountain,belonging to 22 families and 37 genera.In terms of species composition,they are mainly composed of Compositae,Gramineae,and Scrophulariaceae.Dominate.The meadow community on the east slope of Sejila is dominated by Polygonum rotundifolia,while the meadow community on the west slope is dominated by Polygonum viviparum.In terms of the composition of the flora,it can be divided into 4 types and 1 variant according to the distribution type of the family.Among them,the world distribution type is the most dominant,and there is no regional endemic family distribution.According to the distribution type of genera,it can be divided into 8 types and 3 variants.Among them,the northern temperate zone has the largest number of distributions,and there is no China-specific genera distribution.The species composition of the alpine meadow community in Sejila Mountain is more complex than that of the alpine meadow in northern Tibet,and there are more species types that make up the community.The average species diversity index of the alpine meadow community in Sejila Mountain was 3.23,the average richness index was 4.79,and the evenness index average was 0.90.The Shannon-Wiener diversity index,Margalef richness index and Pielou evenness index of Sejila Mountain are consistent in the west slope>east slope,and there are significant differences.It shows that the community on the west slope has more plant species,the community structure is more stable,and multiple species coexist.The number of individuals in the community on the west slope is more balanced than that on the east slope and the species diversity is higher.One-way analysis of variance showed that the aspect had a significant impact on the species diversity of alpine meadows on the eastern and western slopes of Sejila.The total biomass of the alpine meadow community in Sejila Mountain is 428.76～726.14 g/m2,with an average of 534.71 g/m2;the aboveground biomass of the community is 151.63～291.78 g/m2,with an average of203.08 g/m2;The amount is 290.12～434.36 g/m2,with an average of 331.64 g/m2.The biomass of the east slope is significantly higher than the biomass of the west slope.The above-ground biomass,underground biomass,and total biomass all show the same pattern as east slope> west slope.The total biomass on the east slope is 41.28% higher than the west slope,and the above-ground biomass on the east slope It is 65.25% higher than the west slope,and the underground biomass on the east slope is 25.62% higher than the west slope.The root-to-shoot ratio is West Slope(1.89)>East Slope(1.47).The single-factor analysis of variance shows that the aspect has a significant impact on the East-West slope root-shoot ratio,indicating that the underground and above-ground biomass allocation strategies of plants on the east and west slopes are different.different.(2)The total organic carbon(TOC)content of 0-30 cm in the Alpine Meadow of Sejila Mountain is 17.36～88.18 g/kg,and the content of particulate organic carbon(POC)is 2.01～61.62 g/kg.The easily oxidized organic carbon(EOC)content is 2.55～16.658 g/kg,microbial biomass carbon(MBC)content is12.40～331.14 mg/kg,and microbial biomass nitrogen(MBN)content is12.40～168.09 mg/kg,which is higher than that of alpine meadows in northern Tibet The carbon content indicates that the alpine meadow soil of Sejila Mountain has a higher carbon accumulation capacity but is more sensitive to habitat changes at the same time.The proportion of easily oxidizable organic carbon in the west slope is higher than that of the east slope;in the soil from 0-10 cm to 10-20 cm,the decline rate of total organic carbon and easily oxidizable organic carbon in the west slope is higher than that in the east slope.slope.The soil organic carbon composition of the alpine meadow of Sejila Mountain and the difference in soil depth between the east and west slopes are importantly related to the soil p H and microbial composition caused by the climate of Sejila Mountain and its forest area.The content of available nitrogen(AN)in the 0-30 cm of the alpine meadow of Sejila Mountain is 58.76-480.36 mg/kg,the content of available phosphorus(AP)is between 6.20-65.55 mg/kg,and the content of available potassium(AK)is between 0.03 and 0.30.g/kg.The content of each available nutrient showed the order of east slope>west slope,and had surface accumulation.The content of soil available nitrogen and available phosphorus showed significant difference in the east and west slopes(P<0.05),and the content of soil available potassium was in the east and west slopes.The difference was not significant(P>0.05).The content of total nitrogen(TN)in the 0～30 cm of the Alpine Meadow of Sejila Mountain is 1.51～5.94 g/kg,the content of soil total phosphorus(TP)is 0.53～0.95 g/kg,and the content of soil total potassium(TK)is between 1.51 and 5.94 g/kg.4.83～7.99g/kg.Both soil total nitrogen and total phosphorus showed the order of east slope>west slope,and both had surface accumulation.However,total potassium appears as west slope> east slope,contrary to other elements,mainly concentrated in the middle soil(10-20 cm).The single-factor analysis of variance showed that the aspect had an effect on available nitrogen,available phosphorus,and total phosphorus.In the same soil layer,the soil available nitrogen,available phosphorus,and total phosphorus on the east and west slopes showed significant differences(P<0.05),indicating that The slope aspect of Sejila Mountain has a significant impact on the accumulation of soil nutrients.(3)The dominant plants in the Alpine Meadow of Sejila Mountain have C content of 384.55～433.72 g/kg,leaves of N content of 9.83～28.48 g/kg,and leaves of P content of 0.55～2.64 g/kg.The K content is 3.70～16.74 g/kg.The leaf nutrient contents of the alpine meadow in Sejila Mountain are all: C>N>K>P.In terms of the nutrient contents,C,N,and P all show the order of east slope>west slope,and the K content shows the order of west slope> On the east slope,plant leaf nutrient content and soil nutrient content showed similar laws.The C content of plant roots is 376.24～456.33 g/kg,the root N content is 6.33～10.61 g/kg,the root P content is 0.30～0.88 g/kg,the root K content is 3.3～8.48 g/kg,the average value is 4.72 g /kg.The root nutrient contents of the alpine meadow in Sejila Mountain are all: C>N>K>P.In the comparison of root nutrient contents,the content of C and P appears to be east slope>west slope,while the content of N and K appears to west slope.>Dongpo.The performance of this law is different from the law of leaf and soil nutrient content.(4)Soil C/N,C/P,N/P,C/K stoichiometric ratios have the same vertical spatial distribution as C,N,P,K,and decrease from the upper layer to the lower layer,except for the K element.The soil nutrient content is east slope> west slope,while the soil stoichiometric ratio is mostly west slope> east slope,which is the opposite of soil nutrient content.Plants and soil have interactive effects,and there is a close relationship between the two.Correlation analysis shows that the content of soil C,N,and P elements has a significant positive correlation with the content of plant C,N,and P elements.By comparing plant leaves and The correlation between root system and soil is strong and weak,and it is found that the correlation between leaves and soil is stronger.