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Study On Assessment Of Soil Health And Biological Control Techniques For Pinus Tabulaeformis Plantation

Posted on:2018-01-01Degree:DoctorType:Dissertation
Country:ChinaCandidate:J MaFull Text:PDF
GTID:1313330569980420Subject:Forest cultivation
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This research has focus on the soil of man-made forests of Pinus tabulaeformis at the different forest ages within Daqingshan region in Inner Mongolia.Contrast analyses of soil are made by using the following two typical plant communities: birch natural secondary forests and Ostryopsis davidiana bushes.Based on the field investigation and lab analysis,a systematic study on the soil of the planted Pinus tabulaeformis forests during the stage of their development has been carried out from the aspects of soil physical,chemical and biological properties and the relationship among these properties.The mechanism of the impacts of the man-made forests on soil properties at the entire development stage has been probed and the health evaluation on the soil of pinus tabulaeformis man-made forests has been carried out.Based on the study above,the soil health biological control test has been conducted and the main research results are as follows:1.During the growth and development stages of the planted Pinus tabulaeformis forests,forest ages had significant effects on physical properties of the soil.Soil bulk density showed a tendency of gradual decrease with the increasing forest age.Young forest and mature forest has significant difference(P<0.05).It is showed that soil total porosity,capillary porosity,field moisture capacity,capillary and minimum capacity are correlated significantly,and their tendency variation are the same as the increase of forest age.The soil physical properties of birch hardwood forest,and Ostryopsis davidiana are better than those of Pinus tabulaeformis man-made forests.2.The soil of Pinus tabulaeformis man-made forests at the different forest ages presents weak alkalinity,with pH value of ranging from 7.59 to 7.93.As forest ages,soil showed no sign of acidification.The contents variation of the soil organic matter of Pinus tabulaeformis,as well as its total nitrogen,alkali solution nitrogen,total potassium,available potassium and conductivity,features the tendency that two end stages are higher,while the middle parts are getting lower,along with the variation of forest ages.It is indicate that the low content of total potassium,available potassium is one of the limiting factors of the growth of Pinus tabulaeformis man-made forests.3.The similar variation regularity of soil enzyme activity and soil microbial quantity occurred along with the variation of forest ages.Soil enzyme activity and soil microbial quantity are highest in mature forests and they are also closely positively correlated.4.By using the main analysis method,the soil health conditions of Pinus tabulaeformis plantation has been evaluated,and the results are as followed: near-matureforest mature forest > sapling forest > nearly ripe forest > mid-maturation forest and natural forests of Betula platyphylla> Ostryopsis davidiana shrub> Pinus tabulaeformis plantation at different ages.In general,the Pinus tabulaeformis plantations during the entire stage of its growth and development is beneficial to the benign development of soil fertility.It is showed that natural forests of Betula platyphylla and Ostryopsis davidiana shrub have better effects on maintenance of soil fertility.5.It is concluded from the pot experiment that OM + Sp is the best combination pattern for the resistance to drought stress,as well as improving the growth of Pinus tabulaeformis and soil nutrient condition.
Keywords/Search Tags:Man-made forest of Pinus tabulaeformis, Soil health, Comprehensive assessment, Drought resistance, Biological fertilizer
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