【作者】 郑娇；

【导师】 李俊清；

【作者基本信息】 北京林业大学 ， 生态学， 2013， 硕士

【摘要】 油松(Pinus tabulaeformis)具有喜光、耐旱、耐瘠薄土壤、适应性强、生长快等优点,是北方地区的主要造林树种。随着林业碳汇成为国际社会关注的热点,作为暖温带地区的主要造林树种,油松的固碳机制也越来越受到关注。本研究以暖温带地区主要造林树种油松为研究对象,通过设置四个光照梯度[L1(全光照)、L2(25%遮阴)、L3(50%遮阴)、L4(75%遮阴)],四个氮素梯度[N0(0.0)、N1(0.5)、N2(1.5)、N3(2.5)g/kg土],和四个土壤含水量的水分梯度[W1(10%)、W2(30%)、W3(60%)、W4(90%)]探讨了不同光照强度以及光氮互作和光水互作对油松幼苗光合生理特性及固碳能力的影响,以期为暖温带地区主要造林树种的增碳技术提供理论依据。主要研究结果如下：遮阴有助于油松幼苗Pn的提高,导致PSⅡ光化学效率(Fv/Fm)小幅度增加。适度遮阴能够提高油松的生长量和生物量。说明油松幼苗耐遮阴,对弱光的适应能力较强,能高效的利用弱光增加其光合速率,提高生长量及生物量。在同一光照水平下,氮素营养不仅明显增加了油松幼苗的净光合速率,而且还增强了油松幼苗在全光照下对光抑制的抵抗性。这种趋势表明,要想最大化油松幼苗的固碳量,高光强和高氮量的投入是必要的。并且油松幼苗表现出了能够适应高光强的生理生态可塑性。遮光和浇水处理在一定程度上缓解了水分亏缺和强光的胁迫影响,进而提高了油松幼苗的净光合速率和固碳效率。但过度的遮阴和浇水反而会降低油松幼苗的净光合速率和固碳量。这说明油松幼苗在一定程度上具有耐阴性,是耐旱型植物。更多还原

【Abstract】 Pinus tabulaeformis, by virtues of light favorite, drought resistance, barren soil resistance, strong adaptability and fast-growing, is the main afforestation tree species of northern region. With forestry carbon sinks become the focus of the international community, as the main afforestation tree species of warm temperate regions, carbon sequestration mechanism of Pinus tabulaeformis is also received increasing concern.In this study, regarding the warm temperate zone afforestation P. tabulaeformis as the main study target, by setting four light gradient [LI (full sun), L2(25%shade), L3(50%shade), L4(75%shade)], four nitrogen gradient [NO (0.0), Nl (0.5), N2(1.5), and N3(2.5) g/kg soil], and four soil moisture water gradient [W1(10%),W2(30%), W3(60%), W4(90%)], explored the effects of different light intensities, light*nitrogen interaction and light*water interaction on photo synthetic physiological characteristics and the carbon sequestration capacity of Pinus tabulaeformis seedlings, expecting to provide a theoretical basis for carbon increase technologies of warm temperate main afforestation tree. We obtained the following conclusions:Shade was conducive to the improve of Pn in Pinus tabulaeformis seedlings, and resulted in a little increase in PS II photochemical efficiency (Fv/Fm). Moderate shade can increase the growth and biomass of P. tabulaeformis compared to that exposed to full sunlight. This indicates that P. tabulaeformis Seedling is resistant shade, has the ability to adapt to weak light, could efficiently take use of low light to increase its photosynthetic rate, consequently improved growth and biomass.In the same light levels, Nitrogen nutrition not only increased the net photosynthetic rate of Pinus tabulaeformis seedlings significantly, but also enhanced photoinhibition resistance of seedlings in full sunlight. This trend shows that, in order to maximize the amount of carbon sequestration of Pinus tabulaeformis, high light intensity and high nitrogen invest is necessary. This pattern indicates that high light intensity energetic and nutritional cost was necessary to reach PNmax and P. tabulaeformis seedlings showed physiological plasticity which enables the adaptation to higher energy uptake.To some extent, Shading and watering treatment alleviated drought and high light stress, thus improving net photosynthetic rate and carbon sequestration efficiency of P.tabulaefonnis seedlings. But excessive shade and watering it reduced net photosynthetic rate and carbon sequestration efficiency of P.tabulaeformis seedlings. This shows, in a certain extent. P.tabulaeformis seedlings has shade resistance, and is drought-tolerant plants.更多还原