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81.
杨晓民 《林业科技》2003,28(5):15-17
通过对哈思山油松人工林进行调查,并选择样树进行树干解析,建立了胸径与树高、高径比,株率与高径比的回归方程,分析了油松人工林前期生长过程、人工林林分结构和生长规律,为科学生产经营提供了依据。  相似文献   
82.
A mail-out survey questionnaire was developed by the Agroforestry group at the University of Guelph to determine the level of awareness and interest in the adoption of agroforestry systems by landusers from four townships in Wellington County, Ontario. The questionnaire investigated: (1) the current level of knowledge regarding windbreaks, woodlots and plantations, intereropping, riparian plantations and silvipasture, (2) the present level of participation in each of these systems on-farm, (3) the perceived benefits and/or drawbacks of each of these initiatives with respect to total farm income, income diversity, land rehabilitation, land value/equity, soil/water conservation, labour intensity, overhead and return on the term of investment.The majority of respondents were familiar with conventional agroforestry systems such as windbreaks and woodlots/plantations (80%, 62% respectively), therefore the level of interest in the adoption of these practices was significant (74%, 66% respectively). Response rates were lower for silvipasture, riparian plantations and intercropping, most likely as result of the low level of familiarity with these practices (20%, 32%, 4% respectively). Respondents commented that agroforestry systems would have a neutral effect on farm income, and would increase land stewardship. In some cases, interested landusers indicated a willingness to participate in agroforestry systems even though they anticipated increases in overhead and labour intensity; however, this was only true if they held land stewardship as a priority. Landusers were more concerned with the economic aspects of agroforestry, as a determinant to the future adoptability of particular practices. Age, gender, farm operation and farm size were not correlated with the adoption of agroforestry systems.The success of agroforestry programs on farms in the study area is largely dependent on the attitudes and willingness of landusers to participate in non-traditional agricultural systems.  相似文献   
83.
There is growing interest in research to develop potential agroforestry models for temperate climates. In Washington State, recent studies and anecdotal information suggest that agroforestry is already employed by land managers, and if so, this experience should inform future research efforts. Because this population is not well defined, a mail survey was designed to: 1) Assess Washington land manager awareness of agroforestry, 2) assess perceptions of agroforestry as a land management tool, 3) assess the perceived potential opportunities or obstacles for land managers to practice agroforestry, and 4) identify landowner groups believed to be practicing agroforestry in Washington State.Three groups of land managers were surveyed: employees of the Soil Conservation Service (SCS), Washington State University Cooperative Extension Service (WSUCE) and OTHER, consisting of university faculty, private land managers, State and Federal land managers and owners of small natural resource businesses.Agroforestry was not a new concept for most (94%) respondents, further 55% of those familiar with agroforestry were practicing agroforestry or providing advice to landowners who were practicing agroforestry. Use in (government mandated) soil conservation plans on farmland (100% of all respondents) was the most frequently cited potential application for agroforestry in the state followed by range and pasture land and managing non-commercial forest land (both 84%), use on commercial forest plantation (83%) and fruit and nut orchards (61%).Diversifies land use (25%), enhanced productivity (18%), aesthetics (13%) and income diversity (13%) were the four most frequently cited potential advantages to practicing agroforestry. Lack of information (28%), lack of technical assistance (18%), establishment costs (14%) and not an established practice (14%) were the most frequently identified potential obstacles to practicing agroforestry. Respondents suggested there is great potential for application of agroforestry throughout the state, and non-industrial private forest land owners were selected for future study of this potential.  相似文献   
84.
Tick-borne diseases are often encountered in canine clinical practice. In the present study, a molecular epidemiological survey of dogs in Japan was conducted to understand the prevalence and geographical distribution of Babesia spp., Hepatozoon spp., Ehrlichia spp. and Anaplasma spp. Pathogen-derived DNA in blood samples obtained from 722 dogs with a history of exposure to ticks and/or fleas was examined by PCR. The prevalence of Babesia gibsoni, Babesia odocoilei-like species, Hepatozoon canis and Ehrlichia spp./Anaplasma spp. was 2.4% (16/722), 0.1% (1/722), 2.5% (18/722) and 1.5% (11/722), respectively. While B. gibsoni and Ehrlichia spp./Anaplasma spp. were detected in the western part of Japan, H. canis was detected in Tohoku area in addition to western and central parts of Japan.  相似文献   
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87.
大山雀生态的初步观察   总被引:6,自引:0,他引:6  
1997年-1999年,在蟒河自然保护区对大山雀的生态进行了观察.该鸟为林息鸟类,筑巢于树洞、墙洞或石缝中.每年3月-8月繁殖,窝卵数7枚~13枚,多为8枚~9枚.卵的大小约11.9mm×15.8mm,重约13.9g,孵化期12d~14d,巢内育雏期14d.以有害昆虫为食,是农林益鸟.  相似文献   
88.
辽宁省大豆田杂草发生与危害   总被引:1,自引:0,他引:1  
采用倒置"W"九点取样法调查辽宁省大豆田杂草,明确了辽宁省大豆田杂草有19科35种,其中阔叶杂草占74.29%,禾本科杂草占14.29%,其他杂草占25.71%;一年生杂草占54.29%,多年生杂草占31.43%。相对多度达10%以上的杂草依次为藜、鸭跖草、稗草、苘麻、反枝苋、红蓼、马唐、铁苋菜、马齿苋和山苦菜。其中藜和鸭跖草相对多度在30%以上,为辽宁省大豆田杂草优势种群。  相似文献   
89.
金坛区鸟类资源丰富,鸟类区系组成多样化,包含多种珍稀保护鸟类,同时在鸟类的组成上呈现出明显的季节性。通过野外调查和收集资料相结合的途径获得数据,运用植鸟类调查基本原理和方法,对金坛区鸟类资源进行全面整理、定量统计和系统分析,为本地区鸟类资源的保护与合理利用提供了科学依据。  相似文献   
90.
文章通过分析博罗县第四次森林资源二类调查数据,对其森林覆盖率、森林蓄积量、林地地类构成等进行了数据分析,并通过与博罗县第三次森林资源调查数据相比较,调查结果表明博罗县森林资源主要数据变化较大,森林资源总体上呈稳步健康增长的势头。其主要原因一是其森林建设成果,二是调查范围的扩充,三是技术手段革新所带来的系统误差。调查中也发现博罗县部分森林质量仍较低,需要加强相关森林质量提升工作,并在森林资源长足提升后的瓶颈期,及时转变林业发展思路,结合二调数据科学规划,推动现代林业转型升级,增强森林生态服务功能。  相似文献   
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