The Soil Properties Study Of Medicinal Plant Communities In Yang Xian

In this study,we choose Eucommia ulmoides,Macrocarpium officinale,Ginkgo biloba,Forsythia suspensa,Forsythia suspensa-Platycladus orientalis,Chaenomeles cathayensis,Catsiatora Linn,Platycodon grandiflorus,Scutellaria baicalensis 16 medicinal plant communities as the main objects in Qinba mountainYangxian,through field vegetation surveys and indoor sample analysis,determination of soil organic carbon and nutrient content,analysis of the characteristics of vertical distribution;Combining traditional statistics and path analysis method,analysis of different community soil organic carbon and the differences between the correlation of soil physical and chemical properties and soil nutrients on soil organic carbon and the effect of different communities for the study of soil organic carbon dynamics and its change law,provide the basis data for understanding the soil factor effect on soil organic carbon,provide theoretical basis and key control factor.The medicinal plants of the counties also provides a reference index for soil.The main conclusions are as follows:1.The county of medicinal plants and soil physical and chemical properties of soil organic carbon distribution characteristics.The county of different vegetation types of soil organic carbon,organic carbon,carbon,soil total nitrogen and total phosphorus content in soil spatial distribution rule of similar,are presented with the increase of soil depth and gradually reduce the trend;By the results of nutrient distribution together arbor community soil nutrient content is high,the using effects of soil fertility significantly,herbaceous community soil nutrient content,in addition to the st John's wort-using community,shrub community soil nutrients.Different vegetation types of variability of soil organic carbon,coefficient of variation of the height in the order: Chaenomeles > Catsiatora Linn > Forsythia > Ginkgo > Magnolia > Scutellaria > Macrocarpium > Platycodon >Forsythia-Platycladus;Coefficient of variation,the largest is the quince community for moderate variation,the variation coefficient is the smallest forsythia-using mixed low for variation.2.The county medicinal plant community soil organic carbon and soil physical and chemical.Properties of correlation analysis C/N ratio range in different community between 5.58-14.31,Forsythia,Eucommia and Macrocarpium community C/N value is relatively large.Different communities C/P and C/K value is the deepness of soil deepen shows the tendency of decrease.And C/N value decline is not obvious,relatively stable.Correlation analysis results show that the organic carbon and the measurement indicators of soil physical and chemical properties between(except total potassium)are presented.Suggesting that exists between soil nutrients promote or inhibit the relationship between each other,and organic carbon content of high and low influence soil physical,chemical properties and fertility levels.So in the future study of soil carbon sink change rule to consider when the change of other nutrients.3.The county medicinal plant community relationship between soil organic carbon and soil factor.Analysis of the sizeStepwise regression analysis showed that soil total nitrogen,total phosphorus,total potassium,soil bulk density and soil water content and their interaction,is the influence of different vegetation types of the dominant factor on the changes of soil organic carbon content,size analysis showed that the mechanism of soil organic carbon.Plant communities of the study area comprehensive stepwise regression analysis showed that the soil organic carbon important factor affecting the area are the soil total nitrogen and soil water content.4.The county community soil organic carbon and magnolia bark N?P?K distribution characteristics and the coupling relationship research.The county the investment community in the process of growth and development,soil organic carbon,total nitrogen and total phosphorus are shown as the growth of the forest age and gradually reduce the trend,the following order: 2-years old Magnolia officinalis > 4-year old Magnolia officinalis > 7-years old Magnolia officinalis > 7-years old Magnolia > 11-years old Magnolia officinalis.With the increase of soil depth,soil nutrient content gradually decreases,and the change rule of total phosphorus and total potassium is not obvious.Magnolia bark of different forest age communities C/P and C/K as the soil layer deepen showed a trend of significantly lower,and C/N value decline is not obvious,relatively stable.Correlation analysis showed that different colonies magnolia bark of organic carbon and total nitrogen were very significant positive correlation.By comparing the standardized regression coefficient,found that the dominant factor of the investment community soil organic carbon,total nitrogen;The dominant factor of magnolia officinalis pure forest is total nitrogen,followed by total phosphorus,the minimum total potassium;And is the dominant factor of mixed forests,total nitrogen,followed by total potassium,the minimum total phosphorus;Low forest age of Magnolia officinalis community(2a)the dominant factor only total nitrogen.To sum up,the county have significant different medicinal plant community nutrient,soil nutrient content high arbor community,for the use of soil fertility was significant,herbaceous community soil nutrient content,in addition to Magnolia officinalis community,shrub community soil nutrient,the investment community are at the low forest age and forest age stage,soil organic carbon and fertility levels still for degradation stage.Size analysis showed that the factors affect the mechanism of soil organic carbon in different soil.