可持续生计分析框架下退耕户与非退耕户生计状况分析     

唐轲  周易  张志强  孟全省 《西北林学院学报》2013,28(4)

基于西安市周至县退耕山区实地调查数据,运用国际惯用的分析生态工程影响的可持续生计分析框架,建立生计状况评价指标体系,对退耕户与非退耕户的生计状况进行对比分析.结果表明:与非退耕户相比,生计资本方面,退耕户的自然资本和物质资本更为丰富,人力资本和金融资本相对缺乏,社会资本无差异;生计策略方面,退耕户收入更低,支出略低;生计结果方面,退耕户贫困比率更高.并对结果予以解释和提出相应的政策建议.  相似文献   

2010秋季东海今生颗石藻的空间分布     

靳少非  孙军  刘志亮 《勤云标准版测试》2013,33(1):120-131

根据2010年11月东海29站位所采集108个样品偏光镜检分析结果显示:调查区共发现26种今生颗石藻,优势种为赫氏艾密里藻(Emiliania huxleyi)、大洋桥石藻(Gephyrocapsa oceanica)、卡特螺旋球藻(Helicosphaera carteri)和粗壮环翼球(Algirosphaera robusta)等.水体中今生颗石藻丰度为0-76.562个/mL,平均值为18.641个/mL;颗石粒丰度0-4506.47个/mL,平均值为613.44个/mL,今生颗石藻在表层和底层均呈斑块状分布,海盆区站位丰度较近岸站位下降明显,但物种丰富度明显增多;颗石球丰度最大值站位发生在硅藻水华站位.将研究区域划分为3个断面进行分析:PN断面、沿岸流断面和黑潮断面.比较显示,PN断面的空间分布差异性较大,赫氏艾密里藻具有最高丰度的颗石粒和颗石球.沿岸流断面颗石粒/颗石球、黑潮断面中颗石粒(除底层外),自表至底随水深增加有轻微增加趋势,黑潮断面颗石球丰度高值区集中于25-80 m之间.结合历史环境资料,分析得出东海调查期水体混合、泥沙再悬浮以及硝酸盐浓度是控制今生颗石藻物种丰富度与物种特异分布的主要因子;今生颗石藻在不同环境中具有不同的生活策略,其空间分布特征随取样季节和海区不同有较大变化.  相似文献   

优良野生观赏植物槲寄生的观赏性及栽培特性     

王长宝  杨洪升  徐增奇 《中国园艺文摘》2013,29(2):74-75

基于野外调查和文献研究,对槲寄生的形态特征、生长习性及观赏特性等进行介绍,为槲寄生在北方园林早春观叶和秋冬季观杲的应用提供基础资料。  相似文献   

Root‐growth characteristics contributing to genotypic variation in nitrogen efficiency of oilseed rape     

Abdullah Ulas  Gunda Schulte auf'm Erley  Mahmoud Kamh  Franz Wiesler  Walter J. Horst 《植物养料与土壤学杂志》2012,175(3):489-498

A 3‐year field experiment was carried out to determine the significance of root‐growth characteristics contributing to N‐uptake efficiency of two oilseed rape (Brassica napus L.) cultivars differing in N efficiency. Two N treatments were applied, and the core and minirhizotron techniques were used to study root‐length density and number of living roots, respectively. Fertilizer‐N supply increased shoot dry matter, grain yield, total N uptake, and total soil N_min contents particularly in the top soil. Although significant differences occurred in all parameters between years, the interactions between years and cultivars were mostly not significant. Compared to cv. Capitol, the N‐efficient cv. Apex was characterized by a higher grain yield at N0 and a higher N uptake during reproductive growth. This genotype also had a higher root‐length density and more living fine roots particularly in the topsoil layer. Root growth of this genotype was especially high from beginning of shooting to beginning of flowering, while shoot growth and N uptake during vegetative growth were comparatively low. Our results suggest that N‐efficient cultivars can be characterized by a high investment in root growth during the vegetative stage with a comparatively slow shoot growth and N‐uptake rate until beginning of flowering, which, however, continues during reproductive growth. High root production only during reproductive growth seems to be less effective to achieve high N efficiency, because this may lead to a shortage of assimilates for seed filling. High root‐length density at vegetative stages may thus be advantageous for N uptake and reproductive growth and could be a useful morphological character for the selection and breeding of N‐efficient cultivars.  相似文献   

The Farmland and Rural Improvement Project budget under the Agriculture Basic Law in Japan     

Akio?MotosugiEmail author 《Paddy and Water Environment》2003,1(2):59-63

The Farmland and Rural Improvement Project (FRIP) system met socioeconomic needs during the time the Agriculture Basic Law (ABL) was in effect. Four hundred and forty publications and revisions of project execution guidelines between fiscal years (FY) 1960 and 1995 addressed the need to modify the FRIP systems. From the viewpoint of budgets, the budget share of the Farmland Improvement Project (FIP) in annual national public works budgets decreased in close correlation with percentages of gross agricultural product in gross domestic product (GDP). The Rural Improvement Project (RIP) share, however, increased during the same time period, in close correlation with percentages of non-farmers living in rural villages. Consequently, there was little change in the FRIP budget share. These changes in FRIP budget structure brought a certain level of FIP investment per hectare, with no increase since FY 1980. In addition, the RIP investment played a role in narrowing the gap in the living infrastructure investment per capita between urban and rural areas.  相似文献   

天津地区美国白蛾的生活习性及生物防治   总被引：7，自引：2，他引：7  

刘代文  李红  段学慧 《天津农业科学》2005,11(1):40-42

介绍了美国白蛾的形态及在天津地区的生活习性。根据多年应用试验,采用生物农药20%杀铃脲悬浮液4000倍液配加洗衣粉喷雾,要求药液破网至虫体,对杀灭1～3龄幼虫效果显著,室内试验杀伤力达98%,生产应用杀伤力达90%以上。  相似文献   

萤火虫生物学特性及其应用研究^*   总被引：1，自引：0，他引：1  

王郡明  梁醒财  罗佑珍 《云南农业大学学报(自然科学版)》2006,21(5):576-580

 介绍了萤火虫生活史和生活习性、发光机制和发光的作用以及萤火虫荧光素酶的性质、结构和特点,并阐述了萤火虫的应用领域,指出萤火虫是一种非常有利用价值的资源昆虫,人们应该珍惜并保护这种昆虫。  相似文献   

中亚鸢尾的花粉生活力及其授粉   总被引：6，自引：0，他引：6  

董玉芝  昝少平  李宁  吴伟  张林 《东北林业大学学报》2003,31(6):78-79

以野生中亚鸢尾(Iris bloudowii)为试材，在一天不同时间采集花粉测定其生活力；同一时间采集花粉，测定花粉的贮藏能力；在一天的不同时间对去雄套袋的花朵进行人工异花授粉，测定最佳授粉时间；用套袈的方法测定该物种自花授粉是否结实。初步得出结论：当花朵开放后，随着时间的延长，花粉生活力逐渐下降；花粉贮藏时间在24h之内，能保持较强的生活力；最佳授粉时间在上午12时左右；初步测定：中亚鸢尾是自花授粉不亲和性植物。  相似文献   

落实土地政策 强化经营管理促进农垦企业快速发展     

张新广  胡卫东 《热带作物学报》2011,31(4):78-82

20世纪 90年代,部分国有农场曾因改革受挫一度经营困难,实现困难农场脱贫致富,成为当时农场经营管理急需解决的难题。广东农垦广前公司在积极探索中强化管理,落实政策,发展思路明确,主导产业巩固,经济快速发展,利润年年攀高,特别是在“两费自理”、“自营经济”和土地管理方面取得了实效。  相似文献   

“活化石植物”瓦勒迈松繁殖技术的研究进展     

牛艳丽  杜鹃  虞志军 《勤云标准版测试》2009,29(14)

瓦勒迈松是南洋杉科单型属植物,是目前地球上最古老的"活化石"植物之一.现在处于濒临灭绝的状态,必须采取有效的措施来加以保护.国内关于瓦勒迈松的报道还很少.笔者综述了其繁殖技术等方面的研究进展,展望了其应用前景.  相似文献