【摘 要】
:
The dynamics of tree layer biomass was studied by combining 35 sample plots of field census with biomass model estimation in a natural Quercus aliena var.acutes
【机 构】
:
College of Life Sciences Beijing Normal University Beijing 100875,P.R.China“,”Department of Environm
论文部分内容阅读
The dynamics of tree layer biomass was studied by combining 35 sample plots of field census with biomass model estimation in a natural Quercus aliena var.acutesrata community on Mountain Xiaolong in Gansu Province,China.The tree layer biomass of Quercus aliena var.acutesrata community was 183 660 kg/ha,in which the slow growth group accounted for 64.89% of the total biomass.The fast-medium growth group accounted for 33.40% and the coniferous group accounted for 1.38%.The organs biomass was found to be in the following order:trunk>root>branch>leaf.The total biomass accumulated with the development of the community.The total biomass and the biomass of the organs were highest in the mature community and became stable as the community developed.The relative growth rate of organs was in the following order:trunk>branch>root>leaf.The biomass ratio of the slow growth group trees tended to increase and the fast-medium group trees tended to decrease as the community developed,which was reveresed in the decline development stage.The biomass of the coniferous group was very small throughout the development process.
其他文献
在齐文化的起源地——博山,坐落着一座始建于盛唐天宝年间的古建筑——颜文姜祠.颜文姜祠建于唐天宝五年,宋元时初具规模,以后历代都有重修.其正殿为建筑结构史上罕见的“无
自杂交水稻问世以来,制种技术与制种产量发生了两次大的飞跃,且都是在湖南首先突破。70年代,杂交水稻制种需人工割叶剥苞,费工多,成本高,植伤大,影响到植株的正常发育,导致
中国农业科学院作物育种栽培研究所主持的太谷核不育小麦研究是一项育种新技术,在“八五”攻关期间成绩突出,特别是在自花授粉作物中应用了轮回选择育种,这是个创新,培育出
甜菜是我国北方特有的糖料作物,在我国北方农业生产中占有重要地位。目前黑龙江省乃至全国甜菜单产不高、总产不稳,特别是含糖率呈下降趋势,已成为限制我国甜菜糖业发展的障碍性因子。氮素供应不合理是主要原因之一。亚硝酸还原酶(Nitrite reductase,NiR)是植物硝态氮同化过程中一个十分重要的酶,其与硝酸还原酶(Nitrate reductase,NR)偶联完成NO3-的无机同化。目前,与NR相
低酚棉亦称无毒棉,其棉饼、棉油、棉秆、棉叶不经脱毒即能食用或饲用。棉籽富含蛋白质、脂肪,有较高的利用价值。我县自1986年引种试验,4年累计示范3.54万亩,平均亩产皮棉60
随着杂交稻模式化栽培技术的进一步落实,谷城县水稻亩产已突破600kg,但海拔300~600m的低山地区,水稻亩产仅200~350kg,最高仅400kg。为了探索山区水稻高产新技术,针对山区水稻
砖雕艺术在我国的历史中源远流长,是富有民族特色的建筑与景观装饰艺术,是中国古建筑中最为重要的工艺之一。然而随着社会的发展,人们的生活方式逐渐发生了变化,传统的优秀艺
随着新媒体的广泛应用,对于书籍的阅读方式也开始随之变化,如今在中国,多媒体电子书籍相对传统的纸质书籍受到年轻人的广泛追捧,纸质书籍设计正面临着巨大的挑战。在这般情况
本文基于移动终端界面设计所涉诸多要素的特性,在符合可用性要求的基础上,分别从协调性、文化性、动感性、精微性、情境性等五个方面,具体阐述了移动终端界面设计的的审美标
A database called eukaryotic intron database (EID) was developed based on the data from GenBank.Studies on the statistical characteristics of EID show that ther