Research On The Variation Of Soil Quality Of Alder Birch Plantation, Fertilization Effect And Nutrient Diagnosis Of Its Seedlings

Alder birch(Betula alnoides Buch. -Ham.) is a fast-growing commercial tree species in Tropic and Sub-tropic areas of China. Alder birch has been planted with huge amount in southern China in the past few years, and it keeps increasing in the future because of great demands. Nevertheless, very few studies had been conducted on the problems related to its cultivation technique, especially the effects of soil nutrient and soil quality on the seedling growth; which is most limiting factor related to the sustainable development of Alder Birch. To clarify the variation of soil quality and its effect on the forest development, and also as an important part of national key project of 10^th 5-year-plan, Alder Birch plantations with different age ( one year, three years, seven years, thirteen years and seventeen years), and the pure forest of Castanopsis hystrix A.DC. or mixed with Pinus massoniana Lamb, in the similar sites are focused in this thesis. Each sites are scored and sequenced to the data-collected relevant to the soil fertility in the selected plots using PCA, and the dynamic variation of soil quality and maintaining forest productivity in the process of Alder birch's growth have been analyzed in theory. The fertilization effects on Alder birch seedlings are also studied using nutrient diagnosis technique, which is the first time to work out the order of required fertilizer, critical value, DRIS Criterion and the best fertilization prescription for alder birch seedlings. Our results will provide a necessary science and technology support for large-scaled sivilculture,...