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961.
外来移民:自然资源综合保护与开发中一颗潜在的定时炸弹 总被引:4,自引:0,他引:4
Paul Scholte 《Ambio-人类环境杂志》2003,32(1):58-64
引言 数十年自然资源保护工作的开展,已形成了一个全球性富含野生动植物的保护区的网络,从而也为人类留下了一份珍贵的遗产[1].但是许多情况下,在这些保护区开辟时是将相关的村民和牧民赶了出去,这种做法已在人们心灵上留下了深深的伤痛. 相似文献
962.
Environmental contamination with ionic chromium has been identified as a problem at numerous Superfund and RCRA Corrective Action sites. In many cases, contamination of groundwater to levels above existing standards or criteria may be a potential problem both for direct consumption of groundwater and for transport of mobile forms of chromium to areas such as basements where it can becontacted. In the environment, chromium occurs in two forms: trivalent and hexavalent. The trivalent form is generally immobile and nontoxic; hexavalent chromium is generally mobile and toxic. This article first presents the extent of the chromium problem, reviews the environmental chemistry literature on chromium, and reviews existing treatment technology for chromium immobilization in the nontoxic trivalent state. Finally, we present a case study where immobilization of chromium occurred through natural processes allowing a modified no-action scenario for site remediation. 相似文献
963.
964.
The geographic distribution of the animals of Venezuela was analyzed as a basis for a series of guidelines to help develop strategies for their conservation. A total of 313 animal taxa is distributed among 24 geographic units, corresponding to the political divisions of the country. Three different criteria were considered in analyzing these data: (1) the number and density of threatened taxa were used to define a ranking system for geographic units; (2) "hotspots" were identified using the distribution of threatened endemics, and (3) a "critical faunas analysis" was used to determine the minimum number of geographic units needed to maximize the number of sampled taxa. The first two criteria emphasize the importance of protecting habitat in the northern portion of the country, where most human intervention has already taken place. But the southern portion of the country is where most of the undisturbed habitat remains. We suggest that the conservation of the animals of Venezuela must follow a mixed strategy, based on two principles: one, aimed mainly at threatened endemics, should focus on the protection of critical habitat north of the Orinoco river, the second, aimed at all threatened animals— particularly high-risk taxa—should focus on assuring the long-term persistence of the pristine habitat in the south. 相似文献
965.
Ester van der Voet René Kleijn Lauran van Oers Reinout Heijungs Ruben Huele Paul Mulder 《Environmental science and pollution research international》1995,2(2):89-89
In the tradition of the study of materials flows through society, the Substance Flow Analysis (SFA) method and its software tool SFINX are presented. SFA aims at providing the relevant information for a country’s overall management strategy regarding single substances or coherent groups of substances. Three modelling techniques and their possibilities and limitations are discussed: Bookkeeping, static modelling, and dynamic modelling. The computer program SFINX can be used for varoius purposes: (1) to obtain an overview of stocks and flows of a substance in, out and through a nation’s economy and environment for a specific year, (2) to trace the origins of specific pollution problems, and (3) to estimate the effectiveness of certain abatement measures. Each application has its own requirements with regard to data and modelling. 相似文献
966.
This paper explores the concept of packaging stewardship to establish methods that could be used formatively in the development of packaging stewardship programmes or in a post hoc fashion after their implementation. It argues that an independent set of values criteria for evaluation are important at this juncture because of the number of jurisdictions considering packaging stewardship programmes. Additional urgency is added by industry's tendency to promote sales of products through their participation in such programmes. A framework is developed that provides a pathway for future packaging programmesto converge on stewardship.The framework is developed around the notion of a steward, as explored by Lerner and Bookchin, and the principles proposed for the Canadian National Packaging Protocol. The frameworkis illustrated with examples from Germany, France, Belgium, the United Kingdom and Canada. 相似文献
967.
Paul Stephen Corn 《Conservation biology》2003,17(2):622-625
968.
969.
Benthic ecology of the high arctic deep sea 总被引:2,自引:0,他引:2
An analysis is made of 75 quantitative benthic samples collected by Mini-LUBS, and 28 qualitative benthic samples collected with the small biological trawl, from Fletcher's Ice Island, T-3, while it was drifting over the Alpha Cordillera region of the High Arctic Ocean during October, 1969 through February, 1970 and in March, 1972. The depth range was 1000 to 2500 m. Benthic foraminiferans account for about 53%, bivalves for 27%, sponges for 7%, and polychaetes for 5% of the total biomass. Other groups make up the remaining 8%. The weight ratio of macro- to meiofauna is 1:1. Numerically, excluding Foraminifera, polychaetes comprise 42%, nematodes 16%, sponges 11%, and bivalves 8% of the total fauna. The remaining 23% is composed of 13 other taxa. Biomass in the Amerasian Basin at depths of 1000 to 2000 m is extremely low (0.04 g/m); it is comparable to depths of 5000 to 6000 m in the oligotrophic red-clay area of the mid-Pacific Ocean, and is 40 times less than biomass at comparable depths from Antarctica and off Peru. Diversity, as calculated by the Shannon-Weaver method, is low, suggesting that the Arctic ecosystem is young, as reported in earlier studies (Dunbar, 1968; Menzies et al., 1973). Although the H' values are low, no biocoenoses of oligomixity in the deep Arctic are revealed, contrary to previous statements and beliefs. There may be fewer major benthic groups in the Arctic Ocean than in other parts of the world oceans. Following the conventional terminology of Petersen (1913) and Thorson (1957), we have called the High Arctic biocoenoses of the Alpha Cordillera region a Thenea abyssorum-Spirorbis granulatus community. 相似文献
970.
Paul Ramdohr 《Die Naturwissenschaften》1971,58(12):613-615
The iron of the Mundrabilla meteorite contains graphite in very exceptional needle-like forms, obviously in many different polytypes. They are similar to graphite in the iron of the Khairpur meteorite. Here the needles || thec-axis form cross-like twins or thrillings with base faces of ~ 90°. Further growth can fill the interstices to form the cube-like “cliftonite”. 相似文献