Study On Density Effect And Stumping Skill For The Fuel Energy Plantations Of Elaeagnus Angustifolia L.

Elaeagnus angustifolia L. is an emerging energy species with the characteristics of growing rapidly, high heat value and adaptability, etc.There is a vast growth area of Elaeagnus angustifolia L. in the Northwest, only 69,000 acres in Xihe forest region in Ejin River. And it is an important species in the Northwest region of China with a large storage resource. In this paper, the effects of Elaeagnus angustifolia L. peaceful energy forest density and the stumping technology were studied preliminarily, with Elaeagnus angustifolia L.plantation in Yanqing District of Beijing as the object of study. And it would provide theory and technical basis for the development of Elaeagnus angustifolia L. energy forest. The main findings were as follows:(1)A survey about Elaeagnus angustifolia L. energy plantations of different densities showed that: Considering comprehensively from economic and ecological benefits,4444 plants/hm2 was the best planting density in the management of short rotation. The second or the third year can be the best rotation of Elaeagnus angustifolia L.energy plantations.Biomass estimation model was built against the density of 4444 plants/hm2. The SH were selected as independent variables for their best correlation, which were used to be fitted the model with aboveground biomass. W=-1.885+0.549SH-0.01(SH)2.(2)The different stumping heights of biennial Wuhai provenances were studied. The result showed that heat per unit area of stumping height 5cm increased by 1.44 times and 1.02 times respectively compared with stumping height of 0cm and 10cm. From the point of view of stumping for two years merely, the best stumping height was 5cm.(3)The different stumping heights of annual U.S. Elaeagnus angustifolia L. were studied. The result showed that from the point of view of stumping for two years, both stumping heights 0cm and 5cm could be as stumping height.(4)The stumping of U.S. Elaeagnus angustifolia L. was studied in different seasons. The result showed that both single cluster biomass and energy per unit area of Elaeagnus angustifolia L. which were stumped in winter increased 17% than stumped in spring. From the point of view of stumping during the year merely, stumping in winter was better than in spring.(5)There were no differences in the gross calorific values among different sources of the same age...