Study On The Mechanism Of Stellera Chamaejasme L. Population Distribution Of Qinghai Lake

Through the study of the dominant species of grass by Euphorbia in QinghaiLake area, analyzing the physical and chemical properties of the drilling soil sample,exploring the factors that affecting the distribution of Euphorbia populations. Insummary, exploring the reasons which have impact on Euphorbia populationsdistribution based on niche distribution and species competition, removal andchemical control measures of Euphorbia to grassland soil chemical properties andrelationship between Euphorbia populations and other grass species. Provide ascientific basis for the future governance of Euphorbia and theoretical guidance forthe natural recovery of degraded grasslands. The main results are shown as follows:(1) The study area Euphorbia distribution and soil temperature, availablenitrogen content was negatively correlated, and that with soil total potassium contentwas positively correlated, whereas the temperature had the maximum contributionrate to Euphorbia distribution in all of soil environmental factors.(2) After Euphorbia being chemical controlled in grassland, lawn soil pH,available nitrogen, available phosphorus significantly inhibited, indicatingEuphorbia was good for soil fertility improvement and protection, to take chemicalmeasures against Euphorbia had disadvantages of grass available nutrients (nitrogenand phosphorus) accumulation, while in following year the lawn organic and totalpotassium had significantly increased. After mowing and manual removal ofEuphorbia, a significant increase in soil organic matter, and other nutrients changeswere not obvious. Three eradication measures of Euphorbia had no significant effecton soil chemical properties in the0-30cm soil layer changes with soil depth.(3)During the relationship between Euphorbia populations and other grassspecies, first of all, discolor potentilla (Potentilla discolor), picris japonica (Picrisjaponica Thunb) had the largest impact on Euphorbia, second ones were second crackpotentilla (Potentilla bifurca L.), supina potentilla (Potentilla supina Linn.); finallyinclude plantain (Potentilla anserina L.), anserina potentilla (Plantago asiatica L.)and sarcocarp grass (Lancea tibetica Hook. f. et Thoms.). The combination betweenseveral plants and plant Euphorbia correlation coefficient showed that, plantain,anserina potentilla, discolor Potentilla, sarcocarp grass and Euphorbia showed anegative correlation; supina potentilla, picris japonica, two split Potentilla showed a positive correlation with Euphorbia.