果园间种白三叶草对土壤生态及果树生产的影响

针对我国果园长期沿用清耕除草方式所带来的水土流失、土壤肥力下降和果品品质变劣等问题,于1999年在山东省烟台市5个试验点分别设置了由种草样地及其清耕对照样地组成的5组可比样地,对苹果园间种白三叶草(Trifoliumrepens)对土壤生态和果树生产的影响进行定位观测。结果表明:果园种草3a后0—30cm土层有机质含量平均提高3. 3g·kg-1,氮、磷、钾等养分含量有较大提高,尤以表层土壤更明显;土壤含水量得到提高,尤以夏秋多雨季节更明显;种草果园地下5cm处土温夏季比对照平均降低4. 1℃,而冬季升高2. 5℃,使土温的全年变化较为缓和;种草果园果品产量平均增加7. 04%,年产牧草2 130kg·hm-2,每年可增加经济收入5 328元·hm-2。     

城市生态学基本原理的探讨

城市生态学是一门正在发展中的生态学分支,因其产生历史较短,而尚未形成一套成熟的理论体系和研究方法.本文试图应用生态学基本原理来探讨城市生态系统的性质和特点,初步提出了城市生态学的一些原理和研究城市生态系统的指导原则,并提出了环境承载力—人类社会行为和生态环境之间的界面在城市生态系统研究的地位和作用.     

生态脱贫——山区农业县脱贫致富的有效途径——对四川苍溪县生态脱贫模式的分析

10多年来,四川苍溪县结合实际,立足资源优势,因地制宜,不断实践、探索、总结,走出了一条适合山区农村生态脱贫致富的道路,形成了生态脱贫的“苍溪模式”。本文旨在采用生态经济学理论,运用生态工程分析方法,对该模式生态经济的结构、功能进行分析,以探索适合山区农业县生态脱贫的有效途径。     

艾比湖流域核心区景观生态功能区划及生态调控措施研究

在探讨了景观生态功能区划的概念、原则及区划方法的基础上,以新疆艾比湖流域核心区为对象,采用叠置法并利用“3S”技术对研究区进行了自下而上的景观生态功能区的划分,共划分出4个景观生态功能区和9个景观生态功能亚区。分析了各景观功能区的主导生态功能、保护目标,并有针对性地提出了景观生态调控的工程措施和管理措施,为恢复和重建艾比湖流域景观生态安全格局提供科学的参考依据。     

Risk Assessment of Riparian Plant Invasions into Protected Areas

Abstract:  Protected areas are becoming increasingly isolated. River corridors represent crucial links to the surrounding landscape but are also major conduits for invasion of alien species. We developed a framework to assess the risk that alien plants in watersheds adjacent to a protected area will invade the protected area along rivers. The framework combines species- and landscape-level approaches and has five key components: (1) definition of the geographical area of interest, (2) delineation of the domain into ecologically meaningful zones, (3) identification of the appropriate landscape units, (4) categorization of alien species and mapping of their distribution and abundance, and (5) definition of management options. The framework guides the determination of species distribution and abundance through successive, easily followed steps, providing the means for the assessment of areas of concern. We applied the framework to Kruger National Park (KNP) in South Africa. We recorded 231 invasive alien plant species (of which 79 were major invaders) in the domain. The KNP is facing increasing pressure from alien species in the upper regions of the drainage areas of neighboring watersheds. On the basis of the climatic modeling, we showed that most major riparian invaders have the ability to spread across the KNP should they be transported down the rivers. With this information, KNP managers can identify areas for proactive intervention, monitoring, and resource allocation. Even for a very large protected area such as the KNP, sustainable management of biodiversity will depend heavily on the response of land managers upstream managing alien plants. We suggest that this framework is applicable to plants and other passively dispersed species that invade protected areas situated at the end of a drainage basin.     

Antennal responses of the western pine beetle, <Emphasis Type="Italic">Dendroctonus brevicomis</Emphasis> (Coleoptera: Curculionidae), to stem volatiles of its primary host, <Emphasis Type="Italic">Pinus ponderosa</Emphasis>, and nine sympatric nonhost angiosperms and conifers

Summary. Stem volatile extracts from ten trees that are sympatric with the western pine beetle, Dendroctonus brevicomis LeConte (Coleoptera: Curculionidae) were assayed by gas chromatographic-electroantennographic detection analysis (GC-EAD). The extracts were from the primary host, ponderosa pine, Pinus ponderosa Dougl. ex Laws. (Pinaceae); two nonhost angiosperms, California black oak, Quercus kelloggii Newb. (Fagaceae), and quaking aspen, Populus tremuloides Michx. (Salicaceae); and seven nonhost conifers, white fir, Abies concolor (Gord. & Glend.) Lindl. ex Hildebr. (Pinaceae), incense cedar, Calocedrus decurrens (Torr.) Florin (Cupressaceae), Sierra lodgepole pine, P. contorta murrayana Grev. & Balf. (Pinaceae), Jeffrey pine, P. jeffreyi Grev. & Balf. (Pinaceae), sugar pine, P. lambertiana Dougl. (Pinaceae), Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco (Pinaceae), and mountain hemlock, Tsuga mertensiana (Bong.) Carr. (Pinaceae). Sixty-four compounds were identified from the ten trees, 42 of which elicited antennal responses in D. brevicomis, usually in both sexes. In addition, several synthetic compounds, including a number of the antennally-active compounds from the extracted trees and some bark beetle pheromone components, elicited antennal responses in a manner similar to that observed with the extracts. Of the antennally-active compounds known to be present in trees sympatric with D. brevicomis, only geraniol was unique to its host. Four antennally-active compounds were found in the host and in other conifers; five compounds were found only in nonhost conifers; eight compounds were found in either or both of the nonhost angiosperms; eight compounds were found in either or both of the angiosperms and in nonhost conifers, but not in the host; and 19 were found in both the host and in angiosperms and/or nonhost conifers. Several bark beetle pheromone components were found in the stem volatile extracts. Conophthorin was identified from both nonhost angiosperms; exo-brevicomin was identified in A. concolor; verbenone was identified from a number of nonhost conifers; and chalcogran was identified from P. tremuloides. The number of nonhost volatile chemicals that D. brevicomis encounters and is capable of detecting, and the diversity of sources from which they emanate, highlight the complexity of the olfactory environment in which D. brevicomis forages. This provides a basis for further work related to chemically-mediated aspects of foraging in this insect and perhaps other coniferophagous bark beetles, and highlights the need to consider foraging context in the design and implementation of semiochemical-based management tactics for tree protection.     

德州盐渍土改良与开发利用研究

德州市是我国北方土壤盐碱化和次生盐渍化分布最典型的地区之一,20世纪50至60年代就率先在全国进行土壤改良试验,改良成果突出。但是在投入巨资进行工程建设的同时,次生盐渍化现象并没有得到根本性改变,反而出现反弹现象。运用地学原理分析了研究区土壤盐碱化和次生盐渍化的分布和成因,总结出区域盐碱地整治和改良措施,运用生态学和景观生态学原理提出研究区盐碱资源开发利用的经济、社会和生态价值,以及盐碱资源可持续利用的新思路和建议。     

基于RS/GIS技术的“十一五”期间塔里木河流域生态环境质量综合评价分析

"十一五"是新疆经济飞速发展的五年,同时也是重大生态保护工程十五实施期。本文采用国家环境保护部制定的《生态环境状况评价技术规范》(HJ/T192-2006)分别对新疆"十五"末与"十一五"末生态环境质量进行综合评价分析。结果显示:塔里木河流域生态环境质量总体处于较差水平,各县(市)生态环境质量以较差和差为主,二者面积总和在全区总面积60%以上;与"十五"末相比,全区生态环境质量保持稳定,无明显变化。呈现总体趋于稳定,局部区域有所改善的特征。     

合肥市农业旅游观光园的规划设计

通过调查与分析合肥市农业观光园的现状,得出目前合肥市农业旅游观光园存在的问题。结合桃蹊农业桃主题生态园案例分析,指出农业旅游观光园需以特色农业为主题,景观规划鲜明,进行多层次、多元化发展才能达到可持续发展的目的,从而带来更多的经济效益、社会效益和生态效益。     

Post-Fordist transformation,the sustainability concept and social relations with nature: a case study of the Hamburg region

Following the United Nations Conference on Environment and Development, the concept of sustainability in general and of urban sustainability in particular has become increasingly significant in the course of the 1990s. Even if the environmental problems of cities are far from being solved, one can interpret this development as a change in the relationship between society and nature on both a discursive and a material level. At the same time the transition from Fordism to post-Fordism has given rise to new forms of urban entrepreneurialism, with an absolute priority to economic competitiveness on the one hand and sharpened social conflicts on the other. Looking at the case of the Hamburg region, the article discusses the interaction of these processes. Contrary to the understanding of sustainability as a broadly accepted policy goal it conceptualizes sustainability as a terrain of conflict. As such, we will argue, the sustainability concept and the underlying change in social relations with nature contribute to containing the contradictions of capitalist societalization, which in the transition to post-Fordism have become more visible again. Copyright © 2002 John Wiley & Sons, Ltd.