浅谈林业生产中的造林及抚育技术

在林业生产的过程中,采用正确、合理的造林技术和抚育技术,能够提高造林成活率,确保林木健康生长,并在短时间内构建完善的林分结构。而科学的抚育管理,又能进一步挖掘林业发展潜力,提升林地质量和产量,为林业发展创造更多的空间。同时做好造林和森林抚育工作,能够有效地促进林业科学发展,更好地应对全球气候变化的挑战。     

碳纳米管的酸化处理对碳纳米管/聚氨酯复合材料微观结构及性能的影响

对多壁碳纳米管进行酸化处理,并采用原位聚合法制备了碳纳米管/聚氨酯复合材料。利用X射线光电子能谱分析(XPS)、电子扫描显微镜(SEM)、动态力学分析(DMA)研究了碳纳米管酸化与否对复合材料性能的影响。结果表明,碳纳米管经酸化处理后产生了羧基,碳纳米管的原位加入使得复合材料的储存模量和玻璃化转变温度都有所提高,而且经过酸化的碳纳米管对聚氨酯材料的改性要比未酸化碳纳米管对聚氨酯材料的改性效果更为显著。     

农林类高校学风问题及建设对策探讨

从学习目的、学习态度、学习纪律、学习方法、学习兴趣、学习氛围等方面提出并分析了农林类高校的学风问题,从提高认识、抓实专业思想教育、深化教学改革、坚持导管结合、加强校园文化建设等方面提出了加强学风建设的思路与对策。     

Earthworms increase soil microbial biomass carrying capacity and nitrogen retention in northern hardwood forests

Earthworms have been shown to produce contrasting effects on soil carbon (C) and nitrogen (N) pools and dynamics. We measured soil C and N pools and processes and traced the flow of ¹³C and ¹⁵N from sugar maple (Acer saccharum Marsh.) litter into soil microbial biomass and respirable C and mineralizable and inorganic N pools in mature northern hardwood forest plots with variable earthworm communities. Previous studies have shown that plots dominated by either Lumbricus rubellus or Lumbricus terrestris have markedly lower total soil C than uncolonized plots. Here we show that total soil N pools in earthworm colonized plots were reduced much less than C, but significantly so in plots dominated by contain L. rubellus. Pools of microbial biomass C and N were higher in earthworm-colonized (especially those dominated by L. rubellus) plots and more ¹³C and ¹⁵N were recovered in microbial biomass and less was recovered in mineralizable and inorganic N pools in these plots. These plots also had lower rates of potential net N mineralization and nitrification than uncolonized reference plots. These results suggest that earthworm stimulation of microbial biomass and activity underlie depletion of soil C and retention and maintenance of soil N pools, at least in northern hardwood forests. Earthworms increase the carrying capacity of soil for microbial biomass and facilitate the flow of N from litter into stable soil organic matter. However, declines in soil C and C:N ratio may increase the potential for hydrologic and gaseous losses in earthworm-colonized sites under changing environmental conditions.     

全力推进林业有害生物社会化防治进程

本文根据国家对林业有害生物防治工作新要求,分析了我国林业有害生物社会化防治存在的问题,提出全力转变社会化防治理念、尽快完善防治市场机制、进一步加大防治资金投入力度的建议。     

和龙市林业局龙牙楤木的开发利用

龙牙楤木是享誉长白山地区最著名的木本山野菜之一，除了食用价值，还兼有补气安神、强精滋肾的药用价值。由于当地广大群众一直实行掠夺性的采摘方法，致使野生龙牙楤木资源受到严重破坏，其蕴藏量和可采量逐年减少，供需矛盾日渐突出；为保护当地濒危经济植物———龙牙楤木，采取必要的保障措施，综合开发利用，才能使龙牙楤木产业真正成为和龙市多种经营的重要来源之一。     

The routes to fruit: Governance of urban food trees in Canada

Interest in planting urban food trees (UFTs) in public spaces is growing in popularity as a form of urban greening and a potential food source. Currently there is minimal research on the governance and policy aspects of integrating food trees into cities. To fill this gap, we investigated the characteristics of UFT site governance and how it compares to current urban forest governance. Semi-structured interviews were conducted with relevant municipal officials in Calgary, Edmonton, Toronto and Victoria about their perspectives and involvement with UFT sites in their city. A scan of policy documents was completed to supplement the interviews. The interviews were analyzed using a deductive coding framework based on the Policy Arrangement Approach. We found that key actors at the UFT sites were local organizations and site champions, with minimal municipal engagement. Most site resources provided by municipalities were in-kind. There are also basic knowledge gaps about how to care for UFTs. Currently municipal by-laws prohibit the harvesting and removal of plant material, and are at odds with the purpose of UFT sites, with few municipalities fully integrating UFTs in policies. The primary discussion around UFTs centre concerns for public health and safety, management, and use of public space with limited discussions of benefits. This research demonstrates the value of co-governance models to support UFTs, while a shift in focus from risks to benefits could encourage additional resources and policy integration. Further, including UFTs into policy would also support foraging and food tree maintenance in public spaces, and more fully reflect the plurality of urban forest engagement.     

Citizens’ perception of and satisfaction with urban forests and green space: Results from selected Southeast European cities

In this paper the results of the first comprehensive study on perception of and satisfaction with urban forests and green space in seven Southeast European cities are presented. The aims of the paper are to analyse 1) citizen perceptions of the current state of urban forests and green space in their cities, 2) to what extent current urban forests and green space meet their needs and how this can be improved. A cross-sectional study was conducted by using a common face-to-face survey questionnaire. Respondents were selected based on census data though a stratified sampling procedure by taking into account age, gender and city district (n = 384 in each city). The results showed that citizens genuinely care for urban forests and green space in their cities, but are not satisfied with their current state. The respondents found issues related to misbehaviour of other users, the presence and quality of facilities, as well as the presence and quality of management or maintenance the most pressing. There were more statistically significant differences than similarities between cities. Socioeconomic variables explained perceptions only to some extent. Citizens were very supportive of educational campaigns about the importance of urban forests and green space as well as of better enforcement of the existing regulations though having more community wardens that were expected to tackle current unsatisfactory situations. Urban planning and urban forest and green space management in these cities are facing many problems characteristic for post-socialist countries. Study findings are expected to contribute to decision making in urban planning and natural resource management.     

低碳经济下绿色证券市场资源配置研究

随着经济高速发展,高耗能、高污染的问题日益严重,通过绿色证券资源配置可以达到低碳、环保的目的。该文分析了绿色证券市场的资源配置模式,并对中国绿色证券市场的现状进行了分析;最后从上市条件、制度和立法等方面对提高绿色证券市场资源配置效率提出了具体的对策。     

2015年华南4种林业期刊引文对比分析

为探讨林业期刊引文特点,对华南4种林业期刊《桉树科技》、《热带林业》、《广东林业科技》和《广西林业科学》2015年度所刊发的论文引文进行引文量、引文率、篇均引文量、引文类型、引文语种、期刊自引率等6个方面进行对比分析,结果表明:2015年4种林业期刊引文量为442 ～1 839条,平均1094条;篇均引文量7.8～16.4条,平均13.6条;除《热带林业》引文率为94.7％外,《桉树科技》等3种期刊引文率均达100％;均以期刊类引文最多,图书类次之,学位论文、标准、专利等其他引文最少,其平均所占比例分别为82.3％、10.3％和7.5％.4种林业期刊的引文语种为中文与英文两种,其所占比例分别为88.7％与11.3％;平均期刊自引率偏低,为4.3％,与我国农业科学类期刊平均自引率9.7％的差距较大.