发达国家农业生态补贴政策及其对中国的启示

推进农业绿色发展,是加快农业现代化、促进农业可持续发展的重大举措,也是推进农业供给侧结构性改革的必然要求。美国、日本、欧盟等发达国家及地区在践行农业生态补贴政策方面已有多年的经验,且均取得了良好的政策效果。本文从农业生态补贴主体、客体、目的、标准及政策效果等方面,对上述国家及地区的农业生态补贴政策进行梳理与分析,并在此基础之上总结出对于我国的经验启示,其中包括建立健全农业生态补贴法律法规,明确中央及地方政府在农业生态补贴中的职责和定位,因地制宜制定补贴标准,注重生态项目的科学合理设计,构建严格的监督监测机制等。     

Island differences in population size structure and catch per unit effort and their conservation implications for Komodo dragons

Species inhabiting archipelagos are often characterised by high levels of interpopulation divergence (e.g. size related traits). This divergence may, in turn, influence their life-history. To facilitate better management and conservation of the Komodo dragon (Varanus komodoensis), an island endemic, we identified demographic differences between two island populations in Komodo National Park, Indonesia. Comparison of data collected from dragon populations inhabiting Rinca Island and the much smaller Gili Motang Island indicated that between 1994 and 2004, the Komodo dragon population on Gili Motang significantly decreased its: (1) mean body mass, (2) body condition and (3) relative abundance. These results suggest that the numerically small Gili Motang population was oscillating downwards; in contrast, the Rinca Island population had been relatively stable. More importantly these results emphasize the necessity for managers of this priority conservation species to understand further the inherent functional differences among dragon populations to develop island specific management units. Current management practices (e.g. monitoring) instigated by Komodo National Park management ignore small island dragon populations and thus run the risk of being unable to detect adverse effects for populations that are potentially most prone to decline.     

Weed Allelopathy,Its Ecological Impacts and Future Prospects

Summary

The importance, characteristics, positive and negative impacts, and future role of weeds as an integral part of the natural and agroecosystems are evaluated and discussed. Interference between plants in nature and the importance of differentiating between competition and allelopathy are interpreted. Allelopathy as one component of weed/crop interference, allelochemicals from weed species and their possible mechanism of action are listed and discussed. Weed species with inhibitory action against cultivated crops, other weed species, and plant pathogens, as well as self-inhibitory (autopathic) species are reviewed. Stimulatory or inhibitory allelopathic effects of different crop plants, trapping and catching species, and the potential of allelopathic weeds in inhibiting or stimulating certain parasitic weed species are discussed and evaluated. Allelopathy as a mechanism and future strategy for agricultural pest control and farm management and the potential use and development of some allelochemicals as natural pesticides or plant growth regulators are also considered and discussed.     

基于层次聚类的河北省苹果生产能力的实证研究

作为全国苹果主产省,河北省共有11个地区生产苹果,但这11个地区的生产能力参差不齐.现采用层次聚类法,依据生产能力将这些地区分为3类.根据3类地区生产能力的特点,提出河北省苹果产业发展的政策启示:加大科研和技术推广力度;建立和完善加工用果品原料基地;大力推进苹果协会和果农专合组织的建设;建立和完善果品销售市场体系;加强苹果品牌建设.     

“be＋形容词＋of＋宾语”结构的探索

首先分析“be＋形容词＋of＋宾语”结构的语法意义并指出该结构所表示的一种动作或情态关系以及该结构相当于此中形容词的同义及物动词，然后就所收集的两百余个常用于此结构的形容词进行一次梳理，主要根据含义近似性或关联性以及结构特点把它们归纳成十大类，最后指出该结构在刻画人物的外貌衣着、描述人物的行为举止、描绘事物的状况、揭示人物的心理状态、表达人物的情感等五个方面的句法功能，以便帮助英语工作者和学习者理解、记忆、掌握和使用这种语法结构。     

土壤微生物铁循环及其环境意义

铁是土壤中重要的高活性高丰度元素。铁的生物地球化学循环包括铁还原与亚铁氧化两个过程,需要微生物提供基本驱动力,已经成为陆地表层系统研究的国际热点。铁循环控制着土壤有机物矿化、反硝化、甲烷产生、重金属固定等环境过程,是连结土壤养分循环与污染物转化的纽带。从生物地球化学循环的角度,综述了微生物作用下的铁还原、亚铁氧化过程及其主要微生物类群,重点论述了厌氧条件铁还原与亚铁氧化的环境效应及其地球化学机理,以及铁还原与亚铁氧化两个过程的协调及其调控因子。本文将有助于深入理解地球表层的关键环境过程与驱动机制。     

德国林业管理体制和成效借鉴

德国是林业发达国家,完善的林业管理体制是德国增加森林资源、鼓励林业可持续发展和环境保护的重要基础.文中介绍德国森林资源概况、联邦和州层面的森林管理体制以及森林法律法规,分析其对德国林业管理的影响,并提出对我国林业管理的启示.     

中美农作物收入保险产品:比较与启示

农作物收入保险能够对因产量降低、价格下跌或产量与价格共同变化所引致的收入损失提供补偿,因而成为国际农业保险产品发展的方向。美国农作物收入保险运作已经相当成熟,对中国发展收入保险具有重要借鉴意义。采用比较研究法,分别介绍中美两国农业保险的组织架构,阐释两国农作物收入保险产品的具体设计和运作,并将两国农业保险产品置于巨灾保险(CAT)、买入保障水平(BUY-UP)和补充保障选项(SCO)的产品分类框架下进行比较分析。结果表明,中国农作物收入保险以准收入保险产品为主,尚存在产量和价格数据设置不合理、保障水平和保费补贴政策单一等不足。相比之下,美国农作物收入保险种类丰富,以累积多年的农作物产量数据和期货价格数据为基础,提供多档次可供选择的保障水平,保险单元按照个体和农场进行了区分,并设置了差异化的保费补贴政策。因此,从政策性农业保险要追随农业政策发展目标、提高农业保险组织效率和加强农业保险数据建设方面,对我国发展农作物收入保险给出重要启示。     

Long-term realised and projected growth impacts caused by autumn gum moth defoliation of 2-year-old Eucalyptus nitens plantation trees in Tasmania,Australia

Insect damage to production forests has the potential to reduce financial returns by retarding tree growth and causing mortality, however, long-term realised quantification of these losses is rare. In order to help elucidate economic damage thresholds for making spray decisions we capitalised on a natural outbreak of autumn gum moth, Mnesampela privata, in a 2-year-old Eucalyptus nitens plantation. Following the partial chemical control of this insect outbreak we measured the tree growth variables diameter at breast height over bark and height of five differing tree defoliation classes for 75 months following tree damage. At the end of this period a threshold model was fitted to describe the relationship between tree defoliation and realised tree wood volumes. The model revealed that realised stand wood volume was not significantly affected up until defoliation exceeded 60% and then declined sharply after this defoliation level was reached. Further support for this defoliation threshold was evident from multiple comparisons among defoliation classes that showed 50% defoliated trees did not have significantly different wood volume compared to more lightly defoliated trees, but did have significantly greater wood volume compared to trees that were 72% or more defoliated. To determine if the realised differences in wood volume resulted in differences in yield over a plantation rotation the E. nitens growth model NITGRO was used to on-grow trees to age 15 years for a ‘best case’ (type 1 growth response, constant growth rates from last inventory until harvest) and ‘worst case’ (type 2 growth response, divergent growth rates from last inventory until harvest) scenario. The threshold model was then fitted to the outcomes of both scenarios and the economic consequences of defoliation were clearly dependent on the growth function assumed.     

基于创新教育的人才培养模式研究

针对大学生创新教育的现状,结合学校教学活动的实际情况,总结出"课堂教学改革—创新意识培养—科研创新实践"的三步循环教学模式,对提高大学生的创新能力具有重要的理论意义及应用价值,并在农业机械学课程的教学过程中进行实践,取得了良好的效果。