Mangshan Evergreen Broad-leaved Forest Soil Nutrient Distribution Research

Evergreen broad-leaved forest(EBLF),covering a lot of area in China,is the zonal vegetation type in subtropical area.However,under long-term human disturbances,this forest is shifting to include much more degraded area dominated by secondary.The serious destruction of the earth ecological balance of the environment and human survival and sustainable development, forest restoration and forest tending is becoming a crunch time task in front of people, forest soilnutrients on the forest restoration and forest tending more and more attention to the role.Study on forest soil nutrients, so that people can better understand the fertility of the soil forming process and the distribution patterns of soil nutrients, has important significance to implement, promote forest restoration and tending to maintain the balance of ecological environment. With the development of the forest vegetation gradually in-depth study, people began to pay attention to characteristics of nitrogen, phosphorus, potassium in the soil is the main nutrient elements distribution. Through the combined method of using field monitoring and laboratory experiment, initially to Hunan Mangshan nature reserve of evergreen broad-leaved forest, soil total nitrogen of total phosphorus, total phosphorus and available nutrient vertical distribution were studied, and the improvement of efficiency in forest soil, for the study of Mangshan National Forest Park increased soil improvement efficiency, vegetation restoration of breeding and provide important reference for regeneration.In Mangshan National Forest Park in the East set plot, in4different altitude (i.e.1000m,1000-1300m,1300-1600m,1600-1902m) with vegetation types representative in setting standards, sample size is20m×33.3m, a total of15standard plots, the evergreen broad-leaved forest are7. Set of3soil sample and excavating the soil profile in each plot along the diagonal, depth profiles for100cm,0-20cm,20-40cm,40-60cm,60-100cm layered soil, intends to analyze the relationship between the soil nutrient content, horizontal, vertical distribution characteristics and the physical and chemical properties of soil.The main results were brought forth as follows:(1)The soil nutrient content:Mangshan National Forest Park in the evergreen broad-leaved forest of7investigation samples, through experimental analysis,the total nitrogen content in0-100cm layer between the0.314-3.893g·kg-1; K content between9.261-66.546g·kg-1; the content of alkali hydrolyzable nitrogen, available phosphorus and available potassium changes in2.717-66.658g·kg-10.202-4.131g·kg-1,4.508-52.825, g·kg-1range, the average values were10.04,0.541,0.2246g·kg-1; the mean soil nutrient content, the average value of total nitrogen, total phosphorus, total potassium, available phosphorus, available N, K in74samples were:1.542g·kg-1,0.235g·kg-1,31.953g·kg-1,10.04g·kg-1,0.541g·kg-1,0.2246g·kg-1.(2)Law of distribution of soil nutrient:three kinds of nutrient elements Mangshan National Forest Park of evergreen broad leaved forest soil layer0-100cm soil N, P, K the average value was basically with the increase of soil depth and decreased in order of size, are:0-20cm>20-40cm layer>40-60cm layer>60-100cm layer.In different altitude range are compared, the basic trend of nitrogen, phosphorus, potassium and0-20cm layer of three kinds of soil nutrient content was enhanced with the increasing altitude.(3)Physical factors affect soil nutrient content:analysis of soil nutrient content and climate, bulk density, field moisture capacity, soil texture correlation, results showed that:soil area belongs to subtropical montane humid climate, ample sunshine, abundant rainfall, with the temperature rising, the microorganism in the soil of organic matter mineralization rate, nutrient release amount increase increased nutrient, solubility, improve the effectiveness. There is a close relationship between the size of soil nutrient content and soil bulk density, showed a significant negative correlation, the correlation was not significant degree sequence is clay content<silt content<sand content, which is relatively effective nutrients in soil and clay content correlation. Soil organic matter and field moisture significantly positive correlation.(4) Factors of chemical effects of soil nutrient content:analysis of soil nutrient content and pH value, soil organic carbon density relationship, results showed that:in the study area, the soil is acid, the pH value is between4.03-5.23, the soil effective nutrient content and soil pH value significantly correlation between. The pH value was negatively correlated with soil available P in soil, and was positively correlated with available potassium, nitrogen was not significantly associated with hydrolysis. The content of total nitrogen in soil nutrient content and soil organic carbon was significantly positive correlation between the content of total phosphorus, total potassium content, and soil organic carbon is not significant.