Biomass Production Potential and Nutrient Dynamics of Populus deltoides under High Density Plantations
Biomass Production Potential and Nutrient Dynamics of Populus deltoides under High Density Plantations
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高密度人工林下三角杨生物量生产潜力及养分动态
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
S. Gautam
中科院分区：
文献类型：
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作者：
S. Bhardwaj;P. Panwar;S. Gautam
试验采用随机区组设计，在喜马拉雅邦中部丘陵地带，按60 cm×60 cm(27777株/ha)、90 cm×90 cm(12,345株/ha)和120 cm×120 cm(6944株/ha)三种密度进行试验。人工林采伐13年后，在最接近的60 cm×60 cm间隔内生物量最大(218.08t/ha)，其中树干贡献了地上总生物量的90.71%。密度不同，生物量中养分的积累也不同。最大养分出现在最接近的间距。进一步观察到，土壤有机碳含量随着密度的降低而降低。相反，土壤中氮、磷、钾的含量随着林距的增加而增加。研究表明，60 cm×60 cm的土壤养分积累量较高，而凋落物养分归还量小于土壤养分归还量，造成土壤养分亏缺。
The experiment on Populus deltoides was laid out in randomised block design with three densities viz 60 cm x 60 cm (27,777 plants/ha), 90 cm x 90 cm (12,345 plants/ha) and 120 cm x 120 cm (6,944 plants/ha) under rainfed conditions in mid hill zone of Himachal Pradesh. The plantation harvested after 13 years, produced maximum biomass (218.08t/ha) in the closest spacing of 60 cm x 60 cm for which the bole contributed 90.71 per cent of the total above ground biomass accumulation. The nutrient accumulation in the biomass also differed with the density. The maximum nutrients were present in the closest spacing. It was further observed that organic carbon content in the soil decreases with the decrease in density. Conversely, an increase was observed in nitrogen, phosphorous and potassium content of soil with the increase in spacing. Study reveals that accumulation of nutrients in the biomass is higher in 60 cm x 60 cm spacing whereas, the nutrient return through litterfall was less as compared to the total uptake which created nutrient deficit in the soil.