流溪河国家森林公园森林生态系统服务功能间接价值评估

从森林生态系统的效益出发,选取涵养水源、调节气候、净化环境、土壤保持、固碳释氧、维持生物多样性和医疗保健等因子,采用市场价值法、影子价格法、机会成本法等多种手段对流溪河国家森林公园的森林生态系统服务功能的间接经济价值进行估算.结果表明.该森林公园每年的总生态服务价值约为2.18亿元.     

Cost analysis of sand barriers in desertified regions based on the land grid division model

Sand barriers are the most widely used mechanical implements for wind-blown sand control and desertification prevention. However, there is no standard quantitative cost analysis of the sizes and materials required for sand barriers. In this study, based on the original land grid division model for optimal resource utilization, we calculated the total side lengths of square and regular hexagonal sand barriers with the sizes of 1.0 m×1.0 m, 2.0 m×2.0 m, and 3.0 m×3.0 m in a desertified region of t...     

不同施肥处理对果蔗产量、外观品质及经济效益的影响

在广州市番禺区以当地习惯施肥为对照,探讨了不同施肥处理对果蔗产量、外观品质以及经济效益的影响,结果表明:与对照相比,采用氮磷钾配比为1:0.3～0.4:0.8～0.9、每667 m2施氮约46 kg的施肥方法,果蔗的株高、茎粗、有效茎数、单茎重、节数、平均节长以及商品蔗长均有不同程度的增加,果蔗的外观品质得到明显改善,且肥料用量减少、用肥成本降低,经济效益增加。     

中国农民经济组织:理论与发展

农民的组织化是农民实现、保护和促进自身的经济而联合起来的各种经济和政治组织的行动和过程。农民经济组织的发育与农业产业化的发展和农民收入的提高密切相关。合作经济组织是农民经济组织的主体,中国的农民经济组织必须坚持合作社的基本原则。     

基于省域数据的我国耕地非农化与经济发展研究

土地利用与社会经济活动关系密切。耕地作为土地的精华,面积变化与经济发展之间呈现出显著的规律性。通过分析我国经济成熟区、经济成长区和经济欠发达区经济差异特征的基础上,以1999年～2002年耕地面积统计数据为基础,采用相对指标(耕地减少率、耕地非农化率)和绝对指标(耕地建设占用总量和人均占用量)考察耕地减少状况,然后将各经济区域与耕地减少状况进行空间相关分析,结果表明,耕地减少率与区域经济发展水平相关性不显著,而耕地非农化率与经济发展之间存在着良好的相关关系,经济成熟区的耕地非农化率最高;耕地建设占用总量和人均占用量也表现出经济成熟区>经济成长区>经济欠发达区的特点。耕地建设占用程度与经济发展水平呈正向变化趋势。建立土地优化配置机制、推进产业结构升级代换是实现耕地非农化库兹涅茨曲线转化的关键措施。     

模拟林(竹)-草种植模式遮荫对扁穗牛鞭草的光合速率、生长的影响及其经济效益分析

在模拟遮荫条件下对扁穗牛鞭草的净光合速率、生长指标和经济效益进行了分析。结果表明,扁穗牛鞭草在自然光强1 200μmol/(m2.s)左右时达到饱和点,遮荫48%~79%的光强下很难达到光饱和状态;在中、低光强辐射时,遮荫16%~79%的净光合速率仅为全光下的33.8%~86.4%,高光强辐射下,不同遮荫度下的净光合速率为其全光照的35.0%~94.7%;不同光照强度或者同一光照强度的不同遮荫梯度下,扁穗牛鞭草净光合速率都表现出显著差异[F遮荫=44.09>F0.05(3.84),Pv<0.05;F光照=11.72>F0.05(4.46),Pv<0.05];遮荫改变了光照条件,影响光合产物的合成,进而抑制了扁穗牛鞭草的茎粗生长、植株萌发以及生物量的积累,对株高生长则表现为抑制和促进2个方面;不同遮荫梯度下扁穗牛鞭草产值下降幅度为35.0%~83.1%,年产出0.512 3万元/hm2为扁穗牛鞭草种植的临界值,林(竹)-扁穗牛鞭草模式的冠层遮荫度需等于或小于43%,才能有一定的经济效益。     

膨化血粉饲喂生长犬的效果试验

选择健康的2月龄生长犬40只，随机分为3个试验组(A，B，C)和1个对照组(D)，试验组分别饲喂添加5％，10％和15％膨化血粉的复合饲料，对照组饲喂添加8％鱼粉的复合饲料，进行30d饲哏试验。试验结果表明：A，B，C组与时照组相比日增重分别提高18．97％，2．17％和-13．55％；肉料比降低了19．62％，6．19％和-7．69％。     

特种经济动物兽医公共卫生

人类健康、畜牧业和动物卫生是紧密相联的,兽医公共卫生不仅聚焦于食品卫生和环境的污染,保证食品安全,减少食源性疾病的发生,并且在再发和新发人兽共患病的控制中已经起到不可替代的重要作用。文中简述了兽医在公共卫生方面的作用、兽医公共卫生面临的问题和特种经济动物的兽医公共卫生。     

TRANSFORMATION OF AGRICULTURE ON THE LOESS PLATEAU OF CHINA TOWARD GREEN DEVELOPMENT

● Agriculture on Loess Plateau has transformed from food shortage to green development. ● Terracing and check-dams are the key engineering measures to increase crop yields. ● Agronomic measures and policy support greatly increased crop production. ● Increasing non-agricultural income is a key part of increasing farmers’ income. ● Grain for Green Program had an overwhelming advantage in protecting environment. Loess Plateau of China is a typical dryland agricultural area. Agriculture there has transformed from food shortage toward green development over the past seven decades, and has achieved world-renowned achievements. During 1950–1980, the population increased from 42 to 77 million, increasing grain production to meet food demand of rapid population growth was the greatest challenge. Engineering measures such as terracing and check-dam were the crucial strategies to increase crop production. From 1981 to 2000, most of agronomic measures played a key role in increasing crops yield, and a series of policy support has benefited millions of smallholders. As expected, these measures and policies greatly increased crop production and basically achieved food security; but, low per capita GDP (only about 620 USD in 2000) was still a big challenge. During 2001–2015, the increase in agricultural and non-agricultural income together supported the increase in farmer income to 5781 USD·yr^–1. Intensive agriculture that relies heavily on chemicals increased crop productivity by 56%. Steadfast policy support such as “Grain for Green Program” had an overwhelming advantage in protecting the natural ecological environment. In the new era, the integration of science and technology innovations, policy support and positive societal factors will be the golden key to further improve food production, protect environment, and increase smallholder income.     

贺兰山野生有蹄类动物的经济价值及种群动态变化

记述了贺兰山的4种野生有蹄类动物——马麝、马鹿、岩羊、鹅喉羚的经济价值及目前的种群动态变化,对贺兰山野生有蹄类动物的种群致危原因进行了分析,并据此提出了相应的保护管理建议。