Aboveground biomass and nutrient allocation in an agesequence of Larix olgensis plantations

来源 :林业研究(英文版) | 被引量 : 0次 | 上传用户:crylion
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Biomass and nutrient (N, P, K, Ca, Mg) stock in various aboveground tree components (stemwood, stembark, branches and leaves) were quantified in an age sequence of pure Larix olgensis plantations (20, 35, 53 and 69 years old) in Northeast China. The results show that the aboveground biomass allocation in various tree components was in the order of stemwood (62%-83%), branches (9%-21%), stembark (7%-11%) and leaves (1%-6%) for all stands. The proportion of stemwood biomass to total aboveground biomass increased whereas that of other tree components decreased consistently with stand age from 20 to 53 years old, but kept relatively constant with stand age from 53 and 69 years old. The nutrient allocation in various tree components generally followed the same patt as the biomass allocation (i.e. stemwood > branches > stembark > leaves). The proportion of nutrient stock in leaves to total aboveground nutrient stock decreased consistently with increasing stand age, while that in stemwood increased with stand age from 20 to 53 years old but then decreased from 53 to 69 years old. The rate of nutrient removal for stands was estimated at different stand ages under different logging schemes, showing that the rate of nutrient removal would be unchanged when the rotation length was shortened to 20 years by the harvest of stem only, but greatly increased by the harvest of total aboveground biomass. The rate of nutrient removal would be a considerable reduction for all elements by debarking, especially for Ca.
其他文献
采用全光照喷雾扦插育苗设施进行了扦插试验,结果表明,采用当年生千屈菜嫩梢,14~20 d内即可生根,平均扦插生根率可达85.37%,成活率可达94.21%,是千屈菜繁育的一种有效途径。
延边州农委作为农产品质量安全监管行政主管部门,一直以来高度重视农产品质量安全工作,加快转变农业生产方式,严把标准化生产质量关,严抓执法监管,坚决打击农业违法违规行为,消除各种农产品安全隐患,不断提高农产品质量安全水平。   一是全面推广农产品标准化生产。积极开展无公害农产品、绿色食品、有机食品和农产品地理标志认证工作,强化公共品牌认证工作在安全优质农产品生产上的主导作用。截至2011年末,全州农
利用日光温室,塑料大棚、中棚、小拱棚等避雨设施,采用有机无土栽培技术进行短梗五加[Acanthopanax sessiliforus(Rupr.et Maxim.)Harms.]生产,每平方米每茬可产2~3 kg有机鲜
期刊
敦化市是吉林省最大的大豆生产基地,也是国家30个产粮基地县之一。为进一步加快全市农村经济发展、提高农产品的市场竞争力、推进农业可持续发展,敦化市积极调整农业发展主攻方向,在农业标准化生产和农产品质量安全上大做文章。2011年,全市以大力推行农业标准化生产、加快标准化示范基地建设、改善和保护生态环境为基础,以农业龙头企业、专业合作组织、标准化生产基地为主体,以健全农产品质量安全体系为支撑,以保障农产
At present, the most researches on the protected effect of shelterbelt are on the basis of the two scales of forest belts and networks. However, with the furthe
目的提高婴幼儿维生素B1缺乏性脑病的诊断水平。方法回顾性分析45例经临床证实的婴幼儿维生素B1缺乏性脑病患者的临床和CT资料。结果45例患儿在双侧基底节区均见有对称性的“
期刊
按照省、州农委和市委、市政府的总体部署,延吉市农业局认真实践三个代表重要思想,带头贯彻落实科学发展观,把食品安全工作当作重点来抓,把责任落实到位,从源头治理的方针,从实际出发,加强对农产品安全的监管力度,精心组织,认真实施,为全市食品安全工作迈上新台阶和创建“五好延吉”贡献一份力量。   1.加强领导,提高对农产品质量安全工作的认识   为保障农业生产顺利进行,更好地做好食品安全监管工作,确保
期刊