Research On The Nutrient Use Efficiency Of Main Planting Species In South China

Present status of buffering the soil declining in Chinese fir plantations caused by successive planting is mainly by increasing nutrients, improving biomass cycling and changing traditional improper silvicultural measures, but not by choosing Chinese fir with high nutrient use efficiency to adapting soil condition. As we know, the masson's pine were optimized by surveying growth trait such as diameter, height, crown, stem straightness, volume etc. in the masson's pine provenance trial and the families selections, but not by determining the nutrient use status. Another example was Schima superba which was usually used as fire species in South. What's more, it's not only one of the important timber planting species in the South, but also valuable species for soil fertilization. And many investigations have been done in plantation, mixed forest, ecological characters and the water and soil conversation of the Schima superba, but there is no report on the nutrient use status.In order to study the nutrient use efficiency of plantations, the differences of nutrient use efficiency between various provenances, clones and species were studied by surveying biomass and nutrients of Schima superba plantation, different clones of Pinus massoniana and different provenances and clones of Chinese fir (Cunninghamia Lanccolata). In order to realize the nutrient use status of main planting species in South China, and then selecting the better provenances and clones with higher nutrient use efficiency, and large amount of nutrients exhausted caused by fast-growing can be relived. It also provide scientific basis for keeping long-term productivity of plantations. The main results as follows:(1) Average tree and stand biomass of different Chinese fir provenances is quite different. The highest biomass of Fujian Chang Tai provenance is the smallest of the Zhejiang Kaihuai provenance 1.6 times. The biomass of Chinese fir of different provenances is arranged in an order: Fujian Changtai >Anhui Xiuning >Yunnan Wenshan>Chenxi> Hubei Enshi >Henan Luoshan> Guizhou Jinping>Guangxi Rongshui>Guangxi Pubei >Fujian Nanping >Jiangxi Quannan >Henan Shangcheng>Guangdong Huaiji >Sichuan Xuyong >Zhejiang Jiande >Zhejiang Kaihua. Different Chinese fir provenances organs biomass proportion arranges in an order to be: stem >root>bark >branch >leaf> deadwood.(2) Different provenances of Chinese fir leaf nutrient content have certain differences, and it...