Willow tree productivity on fertilizer solutions containing various Ca/Al ratios

This research examined the remedial effect of Ca on H- and Al- depression of willow (Salix viminalis L. 78183) growth. A greenhouse experiment was conducted with willow cuttings for 3 and 30 days in two ammonium nutrient solutions, one at pH value of 5.0 and another at 3.8. Nutrient solutions at pH 5.0 were: no Ca additive (NS); 2.75 mol m-3 Ca(H2PO4)2 (NSCaP); 2.75 mol m- 3 CaCl2 (NSCaCl2). Nutrient solutions at pH 3.8 (NSA) were: no Ca additive (NSA), 2.75 mol m-3 CaCl2 (NSACaCl2), 2.75 mol m-3 Ca(H2PO4)2 (NSACaP); 0, 0.26, 0.78, and 1.56 mol m-3 of Al (Al0, Al1, Al2, Al3) were added to each NSA treatment. Tree growth was best with NSCaCl2 over 3 days, but equal the other treatments at 30 days. Over 3 days, the NSACaCl2 treatment (pH 3.8; Al0) resulted in greater growth than occurred in NSA and NSACaP, but the responses of plant parts were different. Root growth (weight and length) in the presence of increasing Al was reduced in the NSA treatments but improved with the addition of CaCl2 and Ca(H2PO4). Total tree growth for 30 days was lowest in NSA, but highest in NSACaCl2Al0 and NSACaPAl0. Calcium in either Cl or PO4 form increased willow growth by partially reducing the depressive effects of H and Al, and increasing plant nutrient concentrations. Leaf weight, root length, and tissue dry weight, hydration, and several other parameters measured were significantly associated with solution calcium-aluminum balance (CAB) (CAB = Log Ca/Al, molar concentrations). The use of the term calcium-aluminum balance might be useful in predicting tree performance under acid conditions.     

黑龙江省森工系统刨花板工业发展探讨

从扩大规模、提高质量、减少消耗、降低成本、增加产品品种等方面，对黑龙江省森工系统刨花板工业的发展进行了探讨。     

Synergistic Effects of Nitrogen Amendments and Ethylene on Atmospheric Methane Uptake under a Temperate Old-growth Forest

An increase in atmospheric nitrogen (N) deposition can promote soil acidification,which may increase the release of ethylene (C2H4) under forest floors.Unfortunately,knowledge of whether increasing N deposition and C2H4 releases have synergistic effects on soil methane (CH4) uptake is limited and certainly deserves to be examined.We conducted some field measurements and laboratory experiments to examine this issue.The addition of (NH4)2SO4 or NH4Cl at a rate of 45 kg N ha-1 reduced the soil CH4 uptake under a temperate old-growth forest in northeast China,and there were synergistic effects of N amendments in the presence of C2H4 concentrations equal to atmospheric CH4 concentration on the soil CH4 uptake,particularly in the NH4Cl-treated plots.Effective concentrations of added C2H4 on the soil CH4 uptake were smaller in NH+4-treated plots than in KNO3-treated plots.The concentration of ca 0.3 μl C2H4 L-1 in the headspace gases reduced by 20% soil atmospheric CH4 uptake in the NH4Cl-treated plots,and this concentration was easily produced in temperate forest topsoils under short-term anoxic conditions.Together with short-term stimulating effects of N amendments and soil acidification on C2H4 production from forest soils,our observations suggest that knowledge of synergistic effects of NH+4,rather than NO-3,amendments and C2H4 on the in situ soil CH4 uptake is critical for understanding the role of atmospheric N deposition and cycling of C2H4 under forest floors in reducing global atmospheric CH4 uptake by forests.Synergistic functions of NH+4-N deposition and C2H4 release due to soil acidification in reducing atmospheric CH4 uptake by forests are discussed.     

深圳市主要植被类型与生态风景林营造模式

分析了深圳市现状植被的主要类型及其群落结构和特点 ,提出了深圳市生态风景林的树种选择及景观营造模式 .     

光恩乡水土保持果林工程效益分析

简述了宾县光恩乡水土保持果林工程建设模式与建设成果,效益分析表明该果林工程经济和社会效益显,有推广价值。     

基于孤立森林算法的风电齿轮箱轴承故障检测方法

为精准检测齿轮箱轴承故障,实时进行有效监测以保证风电齿轮箱健康运行,提出一种基于孤立森林算法的风电齿轮箱轴承故障检测方法.首先,以齿轮箱轴承温度为故障检测模型的输出变量,采用多尺度图相关算法选择输入变量;然后,提取输入变量的均方根和包络线进行自组织映射神经网络特征融合;最后,以融合值为模型输入量,使用孤立森林算法进行异...     

用TM资料对祁连山部分地区进行针叶林、灌木林分类研究

为了解黑河上游祁连山区水源涵养林十年间的变化状况,对这一典型地区采用TM卫星资料进行了针叶林、灌木林分类。首先对TM资料进行了几何精纠正和投影变换等预处理;再通过选择TM的4、3、2波段做假彩色合成,并结合遥感地面调查,建立了遥感判读解译标志;在以上工作的基础上,采用一种简单的决策树分类方法,成功地对祁连山典型地区的针叶林和灌木林进行了分类,并检验了分类结果。     

SPOT5卫星影像在退耕精确监测中的应用研究

退耕还林(草)是针对水土流失治理、改善西部脆弱的生态环境而采取的一项重大举措。以2003年9月9日获取的庄浪县SPOT5卫星影像为例,讨论了SPOT5卫星影像的正射纠正方法,详细介绍了影像纠正前根据参考图选点误差、数字高程模型的误差精度和传感器内部结合误差三方面对影像纠正应该达到的精度理论值进行评估,以及纠正后对影像几何精度的精度评定的方法。讨论了在缺少蓝色波段的情况下通过波段计算合成真彩色影像的技术和处理方法,并结合退耕还林工程的实际情况进一步探讨了经过处理后的SPOT5影像在退耕信息可视化和精确监测中的应用。     

The evolution of Greenways in China

This paper focuses on the evolution of Greenway planning and implementation in China, and provides a historical context to the Greenway concept. It was found that:

(1) Although the concept of Greenway was an adaptation from the Western World, the Chinese have a history of more than 2000 years of Greenway planning and implementation. Chinese Greenways have been called various names and were planned for various reasons.

(2) The long history of Greenway planning and implementation in China was mainly a “top-down” approach, which, while very effective under a centralized administrative system, often lacked a scientific basis and significant public participation.

(3) The functions of the Greenways were mainly protection and productive, with little concern for human uses such recreational uses of cycling and hiking.

Greenways in China are discussed chronologically and in three categories:

(1) Riparian Greenways run along rivers, streams and water channels. The history of these Greenways dates more than 2000 years, since a time when trees were grown along canals and city moats. They have in modern times evolved into a network of drainage channels.

(2) Greenways along transportation corridors. These Greenways run parallel to state and provincial highways, railroads, country roads and urban streets and evolved from tree plantings along highways. Used exclusively by emperors, the green corridor networks have been systematically planned and constructed at a national scale and directly organized by the central government.

(3) Greenways along farmland for wind protection. These plantings evolved from individual segments of windbreak rows to a network of protective windbreaks and the large, regional scale “Green Great Wall” project running along the northern edge of China.

As Greenways have evolved in China, they reflect changes in ideology, utilization and scale; from protection of production or beautification to ecological and multiple uses, and from small-scale fragments to a systematic regional and national network. The occurrence of disasters, the involvement of state leaders and the influence of science played an important role in the evolution of Greenways in China.The paper also argues that:

• the traditional top-down approach in Greenway planning and implement should be integrated with scientifically based methods;

• recreational uses should be considered and integrated into existing and planned Greenways;

• the recently invoked “city beautiful”, or cosmetic approach to Greenway planning and implementation should be stopped; and

• Greenways should be planned as an critical strategic element of ecological infrastructure at both the regional and urban scale during current rapid and extensive urbanization occurring in China.