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991.
Xu S Hao X Stanford K McAllister TA Larney FJ Wang J 《Journal of environmental quality》2007,36(6):1914-1919
Composting may be a viable on-farm option for disposal of cattle carcasses. This study investigated greenhouse gas emissions during co-composting of calf mortalities with manure. Windrows were constructed that contained manure + straw (control compost [CK]) or manure + straw + calf mortalities (CM) using two technologies: a tractor-mounted front-end loader or a shredder bucket. Composting lasted 289 d. The windrows were turned twice (on Days 72 and 190), using the same technology used in their creation. Turning technology had no effect on greenhouse gas emissions or the properties of the final compost. The CO2 (75.2 g d(-1) m(-2)), CH4 (2.503 g d(-1) m(-2)), and N2O (0.370 g d(-1) m(-2)) emissions were higher (p < 0.05) in CM than in CK (25.7, 0.094, and 0.076 g d(-1) m(-2) for CO2, CH4, and N2O, respectively), which reflected differences in materials used to construct the compost windrows and therefore their total C and total N contents. The final CM compost had higher (p < 0.05) total N, total C, and mineral N content (NO3*+ NO2* + NH4+) than did CK compost and therefore has greater agronomic value as a fertilizer. 相似文献
992.
The invasion of water hyacinth (Eichhornia crassipes) has resulted in enormous ecological and economic consequences worldwide. Although the spread of this weed in Africa, Australia,
and North America has been well documented, its invasion in China is yet to be fully documented. Here we report that since
its introduction about seven decades ago, water hyacinth has infested many water bodies across almost half of China’s territory,
causing a decline of native biodiversity, alteration of ecosystem services, deterioration of aquatic environments, and spread
of diseases affecting human health. Water hyacinth infestations have also led to enormous economic losses in China by impeding
water flows, paralyzing navigation, and damaging irrigation and hydroelectricity facilities. To effectively control the rampage
of water hyacinth in China, we propose a sustainability science-based management framework that explicitly incorporates principles
from landscape ecology and Integrated Pest Management. This framework emphasizes multiple-scale long-term monitoring and research,
integration among different control techniques, combination of control with utilization, and landscape-level adaptive management.
Sustainability science represents a new, transdisciplinary paradigm that integrates scientific research, technological innovation,
and socioeconomic development of particular regions. Our proposed management framework is aimed to broaden the currently dominant
biological control-centered view in China and to illustrate how sustainability science can be used to guide the research and
management of water hyacinth. 相似文献
993.
Copper is the biocide of choice for present-day antifouling (AF) paints. It is also a major source of copper loading in to
the marine environment and, as such, might cause local copper levels to exceed water quality criteria. The present study is
multifaceted and looks into the overall impact of copper-based AF paints on copper concentrations along a 64-km stretch of
the Indian River Lagoon and at Port Canaveral, Florida. This preliminary study is one of the first to outline issues and present
background evidence on the current status of copper and copper-based AF usage in Florida and to address the need for management.
Previous measurements of copper levels in these waters show a history of copper contamination close to marinas, boatyards,
and at Port Canaveral that often exceed state and federal water quality standards. Further, we estimate that the total annual
copper input into the Indian River Lagoon is between 1.7 tons/year (sailboats) and 2.1 tons/year (powerboats) from boats in
14 marinas. We estimate the copper input into Port Canaveral to be about 1.4 tons/year from seven cruise ships. A brief survey
of marina operators and boat owners revealed attitudes and practices associated with AF paint usage that ranged from excellent
to inferior. Management recommendations are made for a proactive approach to improving AF paint selection and application,
assessing the environmental status of copper, and redefining existing management practices for sustainable AF paint usage
and environmental health. 相似文献
994.
The proximity principle—disposing of waste close to its origin—has been a central value in municipal solid waste (MSW) management
in Japan for the last 30 years and its widespread adoption has helped resolve numerous “Not in My Backyard” issues related
to MSW management. However, MSW management costs have soared, in large part because of aggressive recycling efforts and because
most MSW is incinerated in a country that has scarce landfill capacity. In addition, smaller, less sophisticated incinerators
have been closed because of high dioxin emissions. Rising costs combined with the closure of smaller incinerators have shifted
MSW management policy toward regionalization, which is the sharing of waste management facilities across municipalities. Despite
the increased use of regionalized MSW facilities, the proximity principle remains the central value in Japanese MSW management.
Municipal solid waste management has become increasingly regionalized in the United States, too, but different driving forces
are at work in these two countries. The transition to regionalized MSW management in Japan results from strong governmental
control at all levels, with the central government providing funds and policy direction and prefectures and municipalities
being the primary implementing authorities. By contrast, market forces are a much stronger force with US MSW management, where
local governments—with state government oversight—have primary responsibility for MSW management. We describe recent changes
in Japan’s MSW programs. We examine the connections between MSW facility regionalization, on the one hand, and, on the other
hand, the proximity principle, coordination among local governments, central government control, and financing mechanisms. 相似文献
995.
Analysis tools that combine large spatial and temporal scales are necessary for efficient management of wildlife species,
such as the burrowing owl (Athene cunicularia). We assessed the ability of Ripley’s K-function analysis integrated into a geographic information system (GIS) to determine changes in burrowing owl nest clustering
over two years at NASA Ames Research Center. Specifically, we used these tools to detect changes in spatial and temporal nest
clustering before, during, and after conducting management by mowing to maintain low vegetation height at nest burrows. We
found that the scale and timing of owl nest clustering matched the scale and timing of our conservation management actions
over a short time frame. While this study could not determine a causal link between mowing and nest clustering, we did find
that Ripley’s K and GIS were effective in detecting owl nest clustering and show promise for future conservation uses. 相似文献
996.
Bergquist DA 《Environmental management》2007,40(5):787-802
This article discusses environmental sustainability in aquaculture and its contribution to poverty alleviation, based on field
studies in Sri Lanka and the Philippines. The aquaculture practices studied are the monoculture of the black tiger prawn (Penneaus monodon) and milkfish (Chanos chanos) and the polyculture of the two species together with the mud crab (Scylla serrata). Factors affecting economic viability, social equity and environmental impacts in aquaculture are discussed and used to
illuminate local and regional differences between aquaculture in Sri Lanka and the Philippines. Findings indicate that the
most significant difference is the level of participation by local people (i.e., people originating ≤10 km away from the farm
location). In the Philippines, 84 % of the people involved in aquaculture are locals, whereas in Sri Lanka, 55% are outsiders.
Whether differences between the two areas can be explained by analyzing regional conditions, which might have resulted in
different aquaculture practices, is discussed. In Sri Lanka, semi-intensive shrimp monoculture is currently the most common
practice, whereas in the Philippines, extensive shrimp/fish polyculture is more common. Previous studies, as well as fieldwork,
indicate that extensive culture practices reduce environmental impacts and benefit local people more. Sustainability in aquaculture
is, however, also dependent on the extent of mangrove conversion into ponds. As such, extensive and locally owned farms do
not necessarily result in an all but sustainable situation. Keeping this in mind, it is discussed if extensive polyculture
practices might result in a more sustainable aquaculture, both environmentally and socioeconomically. 相似文献
997.
Maintenance of Forest Biodiversity in a Post-Soviet Governance Model: Perceptions by Local Actors in Lithuania 总被引:1,自引:1,他引:0
Successful biodiversity conservation does not depend on ecologic knowledge alone. Good conservation policies and policy implementation
tools are equally important. Moreover, the knowledge, skills, and attitudes of local actors, directly in charge of operations
in the field, are a key to successful policy implementation. The connections between policy objectives and their implementation
as well as the involvement of local actors’ efforts in implementing policy objectives largely depend on the governance model
in use. This article assesses the knowledge of local actors in relation to the biodiversity conservation objectives and tools
in Lithuanian forest management. As a main framework for this study, the needs assessment approach was applied. The study
used both in-depth open-ended interviews and follow-up telephone interviews. Two state forest enterprises in Lithuania were
selected as the study sites. The findings indicate that policy objectives in the field of forest biodiversity conservation
and the related tools are well known but not well understood by those in charge of forest biodiversity policy implementation.
To improve the situation, a transition toward adaptive learning and participatory governance as a means of facilitating conservation
efforts is proposed. 相似文献
998.
Burke A 《Environmental management》2007,40(4):635-648
Little is known about the process of vegetation recovery and associated time frames in the Succulent Karoo Biome of southern
Africa. This study investigated the recovery of vegetation on sites impacted by mining (different types of dumps and mined
areas) in the arid succulent karoo. The main aim of this study was to determine the state of recovery, time frames, successional
stages, and the influence of environmental factors on recovery of coastal dune and sand plain plant communities. For this
purpose, vegetation was recorded on some 121 sites throughout a coastal strip of approximately 100 × 3 km in Namibia’s restricted
diamond area (Sperrgebiet). Using the species pool concept to derive vegetation reference sites and dominance-diversity curves,
recovery of vegetation (measured in terms of species richness and cover) in these altered landscapes reached about 46% on
the oldest, 51-year-old mine dumps. However, based on species richness, richness levels similar to the undisturbed reference
sites were recorded after 30 years, following a logarithmic trend. Successional stages of natural recovery were indicated
in this dynamic coastal environment and Cladoraphis cyperoides and Galenia fruticosa appear to be early successional species. Scaling up of studies to landscape level and developing a target community using
the species pool concept are discussed as means to measure recovery in dynamic biological communities. On these altered, man-made
landforms, the availability of seed may be the bottleneck to achieve vegetation cover comparable to undisturbed vegetation
in the surrounding. Hence, restoration efforts should focus on this aspect. 相似文献
999.
Reed MG 《Environmental management》2007,39(1):30-49
Advocates of community-based approaches to environmental management argue that by respecting local circumstances, skills,
and concerns we may improve the prospects of achieving environmental sustainability; yet, within nation states such as Canada,
environmental conditions, management and enforcement costs and capabilities, and power differentials within and among civic
and public sectors may result in a highly differentiated capacity for environmental management across different localities
and regions. This article draws on insights of political ecology to 1) create a conceptual framework that identifies key elements
shaping regional environmental management regimes and to 2) undertake a comparative analysis to assess how elements interact
to generate uneven management outcomes. I compare experiences of two Canadian biosphere reserves designated in 2000: Clayoquot
Sound, BC; and Redberry Lake, SK. Analysis reveals that differences in governance and institutional capacities in the biosphere
reserves are key to explaining uneven local outcomes. Where the public and civic sectors are strong, a robust and publicly
vetted form of management will emerge. Where these sectors are weak and land is held as private property, environmental nongovernmental
organizations can set the type and level of management, to the exclusion of effective civic and state involvement. This result
may improve environmental sustainability but hinder social sustainability of a management regime and raises questions about
the efficacy of community-based management. 相似文献
1000.
Environmental dredging is a primary remedial option for removal of the contaminated material from aquatic environment. Of
primary concern in environmental dredging is the effectiveness of the intended sediment removal. A 5-year field monitoring
study was conducted to assess the effectiveness of the environmental dredging in South Lake, China. The concentrations of
total nitrogen (TN), total phosphors, and heavy metals (Zn, Pb, Cd, Cu, Cr, Ni, Hg, and As) before and after dredging in sediment
were determined and compared. Multiple ecological risk indices were employed to assess the contamination of heavy metals before
and after dredging. Our results showed that the total phosphorus levels reduced 42% after dredging. Similar changes for Hg,
Zn, As Pb, Cd, Cu, Cr, and Ni were observed, with reduction percentages of 97.0, 93.1, 82.6, 63.9, 52.7, 50.1, 32.0, and 23.6,
respectively, and the quality of sediment improved based on the criterion of Sediment Quality Guidelines by USEPA and contamination
degree values (Cd) decreased significantly (paired t-test, p < 0.05). Unexpectedly, the TN increased 49% after dredging compared to before dredging. Findings from the study demonstrated
that the environmental dredging was an effective mechanism for removal of total phosphorus and heavy metals from South Lake.
Nevertheless, the dredging was ineffective to remove total nitrogen from sediment. We conclude that the reason for the observed
increase in TN after dredging was likely ammonia release from the sediment impairing the dredging effectiveness. 相似文献