Ecosystem Health最新文献

ABSTRACT Forest ecosystems are being degraded and lost because of rapid population change and economic incentives that make forest conversion appear more profitable than forest conservation. All ecological functions of forests are also economic functions. Many important forest functions have no markets, and hence, no apparent economic value, justifying the use of forest land for other purposes. Imputing economic values to nonmarketed benefits has the potential to change radically the way we look at all forests and to make the pendulum swing back from a presumption in favor of forest conversion to more conservation and sustainable use. This paper surveys what we know about forest economic values and draws policy conclusions from the now substantial literature that values nonmarket benefits of forests. Estimating economic values is not enough. The subsequent stage of policy is to design markets that capture the values—‘market creation’—ideally for the benefit of the many vulnerable communities that rely on the forests for their well-being. These conclusions support the wider argument for using effective economic instruments to promote conservation of the remaining forests. Forest loss involves: risks to human health; accelerated climate change; increased watershed disruption, adding to eutrophication in inland and coastal waters; loss of water quality; and loss of biodiversity.

ABSTRACT Numerous anthropogenic factors can deplete calcium (Ca) from forest ecosystems. Because an adequate supply of Ca is needed to support fundamental biological functions, including cell membrane stability and stress response, the potential for Ca deficiency following the individual, cumulative, or potentially synergistic, influences of anthropogenic factors raises important questions concerning organism and ecosystem health. Past work has shown that one Ca-depleting factor (foliar acid mist exposure) reduces concentrations of biologically important membrane-associated Ca (mCa) from red spruce foliar cells, destabilizes these cells, and results in their increased susceptibility to the freezing injury responsible for red spruce decline in northeastern U.S. montane ecosystems. Data presented here indicate that these same disruptions can occur for other tree species and that soil-based Ca manipulation can also alter critical mCa pools. Considering the unique role Ca plays in the physiological response of cells to environmental change and stress, we hypothesize that depletion of biologically available Ca (e.g., mCa) could result in a scenario similar to recognized immune deficiency syndromes in animals. A hypothetical pathway through which anthropogenically induced Ca deficiencies could predispose plants, and possibly animals, to exaggerated injury following exposure to environmental stress is presented, and the potential implications of this scenario to ecosystem health are discussed.

ABSTRACT

The purpose of this work is to describe a version of sustainable development strategy for the so-called “resource dependent territories” (RDT) of Eastern Siberia, which is based on a paradigm of “the infinite value of the integrity of an ecosystem.”

The main feature of RDTs is that the use of nature (natural resources) is practically the only source of economic growth for these regions. This is the result of a long history of previous economic development. RDTs have enormous possibilities both for the destructive and environmentally acceptable use of nature. However, incomes from the destructive use are far greater than those derived from renewable use. The differences often reach two-to-three orders of magnitude. We cannot expect market mechanisms in the economies of the RDTs to guarantee a sustainable use of the environment.

It is declared a priori that the value of ecosystem integrity is much larger than any benefit from the use of its resources. This paradigm can be supported by a comprehensive system of institutional and legal tools. The main directions of this strategy should be defined as follows:

ABSTRACT

Since the beginning of time pollution has been created by human activities. However, the intensity and the severity of the different kinds of pollution have emerged only in the last few decades and many intricate facets have been revealed. It is gradually being recognized that our health and the ecosystem are being severely affected by environmental chemicals that enter the atmosphere. Plants comprise a large portion of our biosphere and constitute a vital link in the food chain. In this review, types of mutagenic chemicals found both indoor and outdoor are given and several higher plant bioassays for screening and monitoring environmental mutagens are discussed. One plant ideal for monitoring and testing for air pollution is Tradescantia. This species has been used to test for mutagenicity of radioisotope-contaminated air following the Chernobyl nuclear accident and monitoring around nuclear power plants. One of the greatest contributions of plant bioassays will be their continued use for ambient air monitoring and testing for genotoxicity which can be carried out on a global scale.

ABSTRACT

The primary goals of this review were to summarize the epidemiological studies carried out in Beijing, China for assessing the health effects associated with both short-term and long-term exposures to air pollution. In these investigations, a time series study design was used to evaluate the health effects of short-term air pollution exposures; cross-sectional and longitudinal study designs were used to evaluate the health effects of long-term air pollution exposures. Taken together, these epidemiological studies provide coherent evidence that short-term exposures to air pollution are significantly associated with adverse reproductive outcomes such as preterm delivery and low infant weight, and excess daily morbidity and mortality, whereas long-term exposures to air pollution are associated with increased respiratory symptoms or bronchitis in adults. Moreover, these investigations suggested a synergistic effect between air pollution and personal smoking. This review of environmental epidemiological studies in Beijing clearly indicates a link between human health and ecosystem health. Concrete measures in air pollution control must be taken to halt degradation of the earth’s ecosystems from a public health viewpoint.

ABSTRACT

The possibilities for using animal indicators for air pollution studies are reviewed. Three major problems are discussed: bioconcentration of trace elements, alterations of physiological parameters, and genotoxic effects. Sentinel species seem to be useful bioaccumulators of environmental trace elements and may be the first choice for detecting pollutants whenever there is a high affinity between the pollutant and a specific animal tissue. Also metallothionein levels of different invertebrate organisms has been shown to be a very sensitive indicator of metal pollution. The assessment of the pulmonary functions, the regulation of airway caliber, and mucociliary clearance in animals exposed to polluted urban air is presented and their advantages for estimating physiological damages induced by air pollution are advocated. Considering the availability of easy techniques to evaluate genetic damage, sentinel species have proven to be an attractive approach to detect genotoxic effects in all kinds of environmental pollution. A continuous effort of the scientific community is necessary to establish the importance of animal sentinel studies on the process of evaluating risks and formulating regulatory procedures.

ABSTRACT

As with all of the world’s ecosystems, the Arctic ecosystem is challenged by anthropogenic inputs. As a result of their global vision of the ecosystem in which they live, the Inuit community is concerned with the fact that traditional food may not be edible due to pollution. As part of a broader ecosystem health research program examining the biological, economic, and cultural impacts of environmental contamination in the Arctic, the aim of our project was to assess Arctic ecosystem health by the tentative bridging of scientific and traditional knowledge. Specifically, the goal was to verify a possible relationship between Inuit perception of the health of their ecosystem and scientific assessment of deformities, pollutant levels, and parasites in Arctic char, an important food source for the Inuit. In order to do this, it was necessary to take into account Inuit knowledge of contamination and perceived effects on human and ichtyofauna health.

Two fish sampling sites were chosen in Ungava Bay, Nunavik, (northern Québec, Canada) and field sampling took place in August 1994 during the upstream migration of Arctic char. While large amounts of parasites were observed, there were no evident signs of fish health alteration such as deformities or very low condition factors despite the common observation by Inuit that deformities were more abundant than in the past. Although the hypothesis that a possible increase in parasitism in fish due to anthropogenic pollutants could be neither proved nor completely disproved (in particular because of a lack of unhealthy fish), the research process has still proved to be useful; namely, to reassure stakeholders about the quality of the fish stocks studied, to enhance dialogues between researchers and the communities involved in the project, to provide an opportunity for regional stakeholders to guide locally relevant research, and to provide researchers with some understanding of the differences between risks perceived by the general population and dangers identified by the experts.