【作者】 包和林；

【导师】 洪伟； 吴承祯；

【作者基本信息】 福建农林大学 ， 生态学， 2009， 硕士

【摘要】 桉树是中国最重要的速生丰产林之一,桉树已发展成一个新兴的产业,因缺乏优良的耐寒品种而主要集中在华南地区,即使在广东北部和福建等地,桉树也常常受到冬季低温的威胁。邓恩桉具有速生性和良好的耐寒能力,对充分发挥桉树的速生优势和有效扩大桉树的发展规模具有重要的意义。杉木是我国南方重要的用材树种之一,自然分布和人工栽培都很广,是中国亚热带地区的典型生态系统。随着杉木小径材市场打开,萌芽更新杉木由于成本低、效益好已成为主产区主要更新方式。大气氮、硫干湿沉降是森林生态系统氮、硫的重要输入途径之一,有关N沉降对森林生态系统的影响的研究主要集中在欧洲和北美的温带区域,而有关硫沉降及氮、硫复合沉降对森林生态系统的影响还少见报道。因此,在酸沉降全球化背景下,本文通过模拟大气氮、硫沉降试验,研究不同氮、硫沉降水平对森林凋落物干物质释放及碳、氮、磷、钾、钙、镁等元素释放的影响,阐明森林凋落物分解对全球酸沉降的响应特征和规律,为森林可持续经营,特别是邓恩桉及杉木人工林可持续经营和酸沉降对森林生态系统及全球变化的影响提供基础数据和理论参考。本试验采用二次正交回归旋转设计,研究模拟氮、硫沉降增加下邓恩桉及杉木幼龄林凋落物分解过程中干物质释放及碳、氮、磷、钾、钙、镁等元素释放动态。结果表明:(1)氮、硫沉降显著影响邓恩桉及杉木凋落物干物质释放。邓恩桉凋落物NO1~NO9各处理凋落物分解系数分别为1.103、0.837、0.764、0.910、0.854、1.045、0.843、0.845和0.915,平均为0.892。周转期分别为2.950、3.557、3.903、3.284、3.511、2.873、3.555、3.531和3.256,平均为3.380 a;干物质残留率的平均值分别为35.1%、43.9%、48.5%、41.3%、46.6%、36.2%、46.4%、47.6%和42.2%,平均为43.1%。杉木凋落物NO1~NO9各处理凋落物分解系数分别为0.816、0.710、0.615、0.734、0.649、0.823、0.667、0.577和0.727,平均为0.702;周转期分别为3.704、4.239、4.860、4.103、4.605、3.681、4.514、5.171和4.141,平均为4.335 a;干物质残留率的平均值分别为43.5%、50.2%、55.5%、47.5%、51.4%、43.3%、53.4%、57.1%和47.8%,平均为50.0%。氮、硫沉降处理下杉木的周转期比邓恩桉的周转期大,杉木叶干物质相对较难释放。氮、硫两因子对邓恩桉和杉木凋落物分解的单因子效应相反,对邓恩桉叶凋落物残留率的影响中,硫沉降相对要大一些;对杉木叶凋落物残留率的影响中,氮要略大一些。邓恩桉及杉木叶凋落物分解过程中,前4个月均没有显著的互作效应,4个月后氮、硫两因子都表现出了交互作用且表现一致,即氮、硫两因子在[-0.5,1.414]编码范围内对凋落物干物质释放的影响存在相互拮抗作用。(2)氮、硫沉降显著影响邓恩桉及杉木凋落物碳、氮元素释放。凋落物分解过程中两树种各处理C残留率均呈下降趋势。氮较难释放,总体表现为以“释放——富集——释放”模式为基础的动态释放过程。邓恩桉凋落物NO1~NO9各处理凋落物碳元素分解系数分别为0.934、0.814、0.810、0.877、0.870、1.025、0.750、0.911、0.898,平均为0.877;周转期分别为3.240、3.714、3.744、3.441、3.496、2.967、4.023、3.335、3.368,平均为3.148 a。凋落物氮元素分解系数分别为0.325、0.136、0.115、0.255、0.149、0.303、0.224、0.143、0.222,平均为0.208。周转期分别为9.047、21.281、25.325、11.497、19.626、9.672、13.112、20.228、13.104,平均为15.877 a。杉木凋落物NO1~NO9各处理凋落物碳元素分解系数分别为0.684、0.729、0.691、0.671、0.655、0.714、0.670、0.760、0.760,平均为0.704;周转期分别为4.256、3.939、4.062、4.266、4.261、4.021、4.376、3.778、3.848 a,平均为4.090 a。氮元素分解系数分别为0.585、0.584、0.600、0.666、0.532、0.627、0.597、0.589、0.623,平均为0.600;周转期分别为4.978、5.070、5.037、4.469、5.659、4.733、4.808、5.029、4.736 a,平均为4.947 a。氮、硫两因子对两树种凋落物碳残留的影响较为复杂,随分解阶段变化而变化。中水平的氮沉降对邓恩桉凋落物碳释放表现为促进作用且在分解初期高水平的硫持续输入可能抑制碳释放,而随着分解进行,逐渐表现为促进作用;整个氮编码水平对杉木凋落物碳释放均表现出促进作用且硫在中编码水平和低编码水平抑制C释放而在高编码水平则增进碳元素释放。氮、硫两因子对两树种凋落物碳释放的互作效应表现相反而对氮释放的影响的互作效应基本一致。氮、硫两因子对邓恩桉凋落物碳残留的影响可能在[-0.5,1.414]编码范围内相互拮抗;氮、硫两因子对杉木凋落物碳残留的影响在[0.5,1.414]编码范围内相互增效。氮、硫两因子对邓恩桉凋落物氮残留的影响可能在[0,1.414]编码范围内相互拮抗。氮、硫两因子对杉木凋落物氮残留的影响可能在[0.5,1.414]编码范围内相互拮抗。(3)氮、硫沉降显著影响邓恩桉及杉木凋落物磷元素释放,对钾元素的释放没有显著影响。邓恩桉凋落物NO1~NO9各处理磷净释放率为65.49%、55.84%、50.50%、59.65%、51.24%、63.03%、55.33%、51.86%和58.39%,平均释放56.81%;钾净释放率为97.34%、96.92%、93.83%、97.24%、94.83%、95.68%、95.63%、94.13%和96.77%,平均释放95.82%。杉木凋落物NO1~NO9各处理磷净释放率为13.81%、0.47%、13.58%、8.39%、-8.61%、11.29%、-0.49%、-15.73%和4.19%,平均释放-0.13%;钾释放率分别为97.04%、97.70%、97.13%、96.79%、96.47%、92.88%、95.78%、94.78%和97.19%,平均释放96.20%。杉木凋落物磷较难释放,邓恩桉凋落物磷易于释放。氮、硫沉降下凋落物分解的最初3个月,氮、硫输入对凋落物磷分解的影响不显著。凋落物分解4个月后,硫素输入表现出促进作用;高水平氮素输入表现出抑制作用(促进磷固持)。凋落物分解4个月后,总体上氮、硫两因子在[-0.5,1]编码范围内对凋落物磷释放相互增效。(4)氮、硫沉降显著影响邓恩桉及杉木凋落物钙、镁元素的释放没有显著影响。更多还原

【Abstract】 Eucalyptus Dunnii is the most important one of the fast-growing and high-lin in china and has developed into an emerging industry.Eucalyptus Dunnii mainly concentrated in southern china because of the lack of good cold-resistant varieties.Even in the northern part of Guangdong and Fujian,Eucalyptus Dunnii was threatened by hypothermia in winter.Dunnii Eucalyptus gives full play to the advantage of fast-growing Dunnii Eucalyptus with its growing speed and good cold endogenous capacities and Eucalyptus to expand the scale of development effectively is of great significance. Cunning hamia lanceolata (lamb.) Hook is a kind of important timber tree with natural distribution and cultivation widely and is a typical subtropical ecosystem in China.Withe the parth of the small-caliber Chinese fir wood market opened,as a result of cost-effective,budding fir updated has become a mainly way to update in the main producing areas.The wet and dry atmospheric nitrogen and sulpur deposition is one of the important input of nitrogen and sulpur in forest ecosystems The researchs about nitrogen deposition on forest ecosystems mainly concentrated in the temperate zone in Europe and North America region and the sulpur deposition and nitrogen and sulpur deposition on forest ecosytems also rare reports.Therefore,in the context of acid deposition globalization,this paper by simulating the atmosphere of nitrogen and sulfur deposition tests of different nitrogen and sulfur deposition levels on the forest litter dry matter and the elements release of C, N, P, K, Ca, Mg released the impact of forest litter decomposition to clarify the global response to acid deposition characteristics and rules of sustainable forest management,especially in Chinese fir plantation E.dunnii and sustainable management and acid deposition on forest ecosystems and the impact of global change provide the basic data and theoretical reference.Dynamic of the Dunnii Eucalyptus and Chinese fir plantation leaf litter decomposition and C, N, P, K, Ca, Mg release under increasing nitrogen and sulfur deposition by the quadratic rotatio-northogonal combination design were studied. The results indicated that:(1)The Dunnii Eucalyptus and Chinese fir plantation leaf litter decomposition was effected by the nitrogen and sulpur deposition significantly. For the 9 treatments of Dunn Eucalyptus plantation,NO1 to NO9,the decomposition coefficients determined by Olson equation were respectively 1.103, 0.837, 0.764, 0.910, 0.854, 1.045, 0.843, 0.845 and 0.915 with average of 0.892 and with the turnover time of 2.950, 3.557, 3.903, 3.284, 3.511, 2.873, 3.555, 3.531 and 3.256 with average of 3.380 a. The average mass remaining ratio were 35.1%, 43.9%, 48.5%, 41.3%, 46.6%, 36.2%, 46.4%, 47.6% and 42.2% with average of 43.1%. For the 9 treatments of Chinese fir plantation,NO1 to NO9,the decomposition coefficients determined by Olson equation were respectively 0.816, 0.710, 0.615, 0.734, 0.649, 0.823, 0.667, 0.577 and 0.727 with average of 0.702 and with the turnover time of 3.704, 4.239, 4.860, 4.103, 4.605, 3.681, 4.514, 5.171 and 4.141 with average of 4.335 a. The average mass remaining ratio were 43.5%, 50.2%, 55.5%, 47.5%, 51.4%, 43.3%, 53.4%, 57.1% and 47.8% with average of 50.0%. The dry matter of Chinese fir litter was difficult to release and the turnover time of the Chinese fir litter was bigger than the Dunn Eucalyptus litter.The main effect of the two factors,nitrogen and sulpur,to the dry matter release was opposite between the Dunn Eucalyptus and Chinese fir plantation with sulpur playing much more important to the Dunn Eucalyptus dry matter release and nitrogen playing much more important to the Chinese fir dry matter release.There wes no significant interaction effects in the first 4 months and the two factors showed a consistent performance 4 months later with the mutual antagonism in the coding range of [-0.5,1.414].(2)The Dunnii Eucalyptus and Chinese fir plantation leaf litter carbon and nitrogen elements release was effected by the nitrogen and sulpur deposition significantly.For NO1 to NO9,there was a decreasing tendency of the carbon remaining rate of the Dunnii Eucalyptus and Chinese fir plantation leaf litter and the nitrogen was rather difficult to release with the basic release model of“release-enrichment-release”. For the 9 treatments of Dunnii Eucalyptus plantation,NO1 to NO9,the decomposition coefficients of carbon determined by Olson equation were respectively 0.934, 0.814, 0.810, 0.877, 0.870, 1.025, 0.750, 0.911 and 0.898 with average of 0.877 and with the turnover time of 3.240, 3.714, 3.744, 3.441, 3.496, 2.967, 4.023, 3.335 and 3.368 with average of 3.148 a.The decomposition coefficients of nitrogen determined by Olson equation were respectively 0.325, 0.136, 0.115, 0.255, 0.149, 0.303, 0.224, 0.143 and 0.222 with average of 0.208 and with the turnover time of 9.047, 21.281, 25.325, 11.497, 19.626, 9.672, 13.112, 20.228 and 13.104 with average of 15.887 a. For the 9 treatments of Chinese fir plantation,NO1 to NO9,the decomposition coefficients of carbon determined by Olson equation were respectively 0.684, 0.729, 0.691, 0.671, 0.655, 0.714, 0.670, 0.760 and 0.760 with average of 0.704 and with the turnover time of 4.256, 3.939, 4.062, 4.266, 4.261, 4.021, 4.376, 3.778 and 3.848 a with average of 4.090 a. The decomposition coefficients of nitrogen determined by Olson equation were respectively 0.585, 0.584, 0.600, 0.666, 0.532, 0.627, 0.597, 0.589 and 0.623 with average of 0.600 and with the turnover time of 4.978, 5.070, 5.037, 4.469, 5.659, 4.733, 4.808, 5.029 and 4.736 a with average of 4.947 a. The effect of the nitrogen and sulpur depositon to the litter carbon release was complex and changed in the decomposition course. The Dunn Eucalyptus carbon release was promoted by the middle level nitrogen loads and may be inhibited by the high level sulpur depositon in the early stage and changed to promotion effect later.The Chinese fir carbon release was promoted by the additional nitrogen loads in the coding range of [-1.414, 1.414] and inhibited by sulpur deposition in the coding range of [-1.414, 1] and promoted in [1, 1.414] coding range. The interaction effect was opposite to the carbon release and to the nitrogen release the interaction effect was basically the same.The two factors of nitrogen and sulpur may antagonize to each other in [-0.5, 1.414] to the carbon remaining of the Dunn Eucalyptus litter and to the Chinese fir litter nitrogen and sulpur may mutual enrich in the coding range of [0.5, 1.414]. The two factors may mutual antagonize in [0, 1.414] to the nitrogen remaining of the Dunn Eucalyptus litter and in [0.5, 1.414] of the Chinese fir litter.(3)The Dunnii Eucalyptus and Chinese fir plantation leaf litter Phosphorus elements release was effected by the nitrogen and sulpur deposition significantly and there was no significant effect to the Potassium release. For the 9 treatments of Dunnii Eucalyptus plantation,NO1 to NO9,the Phosphorus release ratio were respectively 65.49%, 55.84%, 50.50%, 59.65%, 51.24%, 63.03%, 55.33%, 51.86% and 58.39% with average of 56.81% and with the Potassium release ratio of 97.34%, 96.92%, 93.83%, 97.24%, 94.83%, 95.68%, 95.63%, 94.13% and 96.77% with average of 95.82%. For the 9 treatments of Chinese fir plantation,NO1 to NO9,the Phosphorus release ratio were respectively 13.81%, 0.47%, 13.58%, 8.39%, -8.61%, 11.29%, -0.49%, -15.73% and 4.19% with average of -0.13% and with the Potassium release ratio of 97.04%, 97.70%, 97.13%, 96.79%, 96.47%, 92.88%, 95.78%, 94.78% and 97.19% with average of 96.20%.(4) There was no significant effect to the Ca and Mg release of The Dunnii Eucalyptus and Chinese fir plantation leaf litter.更多还原