Soil Quality Control Of Chinese Fir Plantation Based On Undergrowth Vegetation Development

In order to find plants which could grow well under Chinese fir plantation and improve the soil quality.Our research object was second generation Chinese fir plantation and we chose Dalbergia hupeana,Taxus chinensis,Spatholobus sinensis and Kaempferia galangal for Chinese fir plantation and combined them in five different ways.Through the analysis of plants growing condition,soil nutrients,soil enzyme activities and soil microbial diversity after plantation,we finally chose suitable plant and the best planting pattern for improving soil quality at every ages,which can provide theoretical data and technical support for the further exploration of plant choose and improvement of soil quality in Chinese fir plantation underground vegetation.The results were as follows.(1)There were many kinds of plant species under Chinese fir plantation,belongs to 97 species,75 genus and 53 families.There were fewer species of understory plants at young and middle-aged forests,and the understory vegetation gradually recovered from near-mature forests.Maesa japonica?Dryopteris fuscipes?Diplazium were dominant species in Chinese fir plantation.(2)These five planting patterns had obvious effects on the diversity and richness of soil fungi at young,middle and near mature Chinese fir plantation,and also had obvious effects on the diversity and richness of soil bacteria at young plantation.These five planting patterns had little effect on soil microbial diversity at other Chinese fir plantation.the soil microbial community structure of different planting patterns at different ages was basically different.(3)Generally speaking,treatment 5 can improve soil nutrients better than other models.Under treatment 5,soil organic matter content increased by30.81%,total nitrogen content increased by 45.77%,total phosphorus content increased by27.59%,available phosphorus content increased by 243.62%,available nitrogen content increased by 41.66%,available potassium content increased by 20.75%,soil urease activity increased by 35.74%.Treatment 1 can improve soil nutrients better than other models at middle and near mature Chinese fir plantation.Under treatment 1 of middle-aged forest,thecontents of soil organic matter,total nitrogen,available nitrogen and available phosphorus increased 31.87%,28.95%,43.94% and 174.35%.In near mature forest,the treatment 2increased soil total nitrogen(62.73%),available phosphorus(44.08%)than control group.In mature aged forest,treatment 1 increased soil total nitrogen(13.97%),available nitrogen(62.56%),available phosphorus(326.86%)and urease activities(32.76%)than control group.In over-mature forest,treatment 1 increased soil organic matter(44.20%),total phosphorus(16.28%),available nitrogen(248.74%),available potassium(51.28%)and acid phosphatase activities(63.76%)than control group.