新疆草地生态价值及其可持续开发利用初探

草地是新疆农业自然资源的重要组成部分,是发展草地畜牧业的重要基础,通过对新疆草地特点阐述以及对草地生态价值的量化研究,本文在新疆草地开发利用现状的基础上,针对新疆14个主要草地区提出了草地开发利用的具体措施。     

An Aretaic Objection to Agricultural Biotechnology

Considerations of virtue and character appear from time to time in the agricultural biotechnology literature. Critics of the technologies often suggest that they are contrary to some virtue (usually humility) or do not fit with the image of ourselves and the human place in the world that we ought to embrace. In this article, I consider the aretaic or virtue-based objection that to engage in agricultural biotechnology is to exhibit arrogance, hubris, and disaffection. In section one, I discuss Gary Comstock's treatment of this objection. In section two, I provide an alternative interpretation of the objection that more accurately reflects the concerns of those who offer the criticism than does Comstock's standard interpretation. In sections three and four, I assess the objection. I argue that despite its merits, the objection does not justify global opposition to agricultural biotechnology. Instead, it favors a limited endorsement position not unlike the one defended by Comstock.     

A NEW FLASHINESS INDEX: CHARACTERISTICS AND APPLICATIONS TO MIDWESTERN RIVERS AND STREAMS1

ABSTRACT: The term flashiness reflects the frequency and rapidity of short term changes in streamflow, especially during runoff events. Flashiness is an important component of a stream's hydrologic regime. A variety of land use and land management changes may lead to increased or decreased flashiness, often to the detriment of aquatic life. This paper presents a newly developed flashiness index, which is based on mean daily flows. The index is calculated by dividing the pathlength of flow oscillations for a time interval (i.e., the sum of the absolute values of day‐to‐day changes in mean daily flow) by total discharge during that time interval. This index has low interannual variability, relative to most flow regime indicators, and thus greater power to detect trends. Index values were calculated for 515 Midwestern streams for the 27‐year period from 1975 through 2001. Statistically significant increases were present in 22 percent of the streams, primarily in the eastern portion of the study area, while decreases were present in 9 percent, primarily in the western portion. Index values tend to decrease with increasing watershed area and with increasing unit area ground water inputs. Area compensated index values often shift at ecoregion boundaries. Potential index applications include evaluation of programs to restore more natural flow regimes.     

我国黄土高原地区农业生产的气候脆弱性变化预测

在生态脆弱的黄土高原地区,农业生产受到气候变化的影响波动很大。本文在介绍脆弱性的有关定义和农业生产的气候脆弱性评估方案的基础上,对1997年的脆弱性状况做了初步评估,并利用有关GCM预测结果,估算了有关灾害指标的可能变化,对未来黄土高原地区农业生产的气候脆弱性可能变化进行了预测,其评估方法和预测结果可为有关部门决策提供一定的科学依据。     

河西走廊的农业资源与集约化生产结构

通过对甘肃省河西走廊农业自然资源优势的分析,本文讨论了光热资源和水资源潜力的开发利用,提出用高新技术手段建立集约化的半闭路式生态农业生产体系,促进河西走廊农业再上新台阶．     

依托热带资源优势,开发海南功能食品

本文论述了我国功能食品的定义,起源和发展,着重阐述了海南省具有开发功能食品的热带资源,市场和资金优势,并根据海南省的特点和当前我国功能食品的开发现状与发展前景,提出了海南省开发功能食品的措施。     

论土地资源的永续利用

土地资源是最重要的自然资源,而土地资源的永续利用是实现社会、经济和生态可持续发展的基础。本文分析了土地资源永续利用的重要性,讨论了土地永续利用的概念、内涵、判据、利用方向和模式等内容,并在此基础上提出了实现我国土地资源永续利用的生态经济措施。     

汕头经济特区二次创业与农业产业化

本文介绍了农业产业化的基本理论,分析了汕头经济特区的经济现状与问题,并提出了汕头经济特区发展农业产业化的建议。     

福建省农业自然资源持续利用探讨

本文分析了福建省农业自然资源利用中存在的突出问题及其形成原因,并根据持续发展新模式提出了持续利用的对策。     

黄河三角洲农业开发与可持续发展研究

本文分析了黄河三角洲农业开发的有利条件、开发现状和存在的主要问题,探讨了农业生产的合理布局,提出了农业可持续发展的对策．