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1.
An agricultural watershed, situated on an island of the Aegean archipelago, was studied in order to gain insight into the
structure and the design of a typical terrestrial ecosystem of the Mediterranean region. Fieldwork was focused on the comparative
study of seasonal patterns of inorganic nutrients, organic nitrogen, and erosion over the most abundant vegetation types of
the area, such as olive groves, maquis, and wetlands. Nutrient losses via the pathway of erosion were provided by the determination
of nutrient concentrations in runoff sediments. Results showed that nutrient levels are higher and more susceptible to rapid
changes in the zones that host agricultural activities and animal husbandry. The behavior of nitrogen and phosphorus showed
remarkable stability in the maquis, where dynamic processes were mainly affected by soil erosion, which led gradually to land
degradation, especially on sloping terrains. The aim of this study was to form the basis for the quantification of the interconnections
within the Mediterranean-type ecosystems and to conceptualize their operational properties. 相似文献
2.
1.Information on all maps, including those which depict characters of the natural environment, is subject to locational error. 2.Locational errors on field-sketched maps are attributable to inaccuracies both in the base map itself and in the method of locating and recording features onto the base map. 3.Two main sources of error associated with field sketch mapping were quantified using the River Corridor Survey maps as an example. First, channel widths are routinely exaggerated on these maps to allow recording of in-channel features. Distortions of river bank length of the order of 25% were shown to arise from a four-fold exaggeration of the width of a sinuous channel. Second, discrepancies in feature location of the order of 20% were found along a 500 m river stretch, although errors could be reduced to approximately 2% if undistorted, large-scale base maps were used. 4.An abundance scale appropriate to the inherent locational inaccuracy was devised to extract semi-quantitative information from River Corridor Surveys recorded on distorted base maps. Application of this scale to 29 River Corridor Survey maps of a 14·5 km river corridor produced a useful representation of environmental gradients within the corridor. 5.With the increasing potential to integrate and analyse environmental information within large computer databases including Geographic Information Systems, it is essential that the level of accuracy is recognised and quantified so that the errors can be allowed for in the development of methods of extracting information from the maps. 相似文献
3.
Modelling the Ecological Vulnerability to Forest Fires in Mediterranean Ecosystems Using Geographic Information Technologies 总被引:1,自引:0,他引:1
Beatriz Duguy José Antonio Alloza M. Jaime Baeza Juan De la Riva Maite Echeverría Paloma Ibarra Juan Llovet Fernando Pérez Cabello Pere Rovira Ramon V. Vallejo 《Environmental management》2012,50(6):1012-1026
Forest fires represent a major driver of change at the ecosystem and landscape levels in the Mediterranean region. Environmental features and vegetation are key factors to estimate the ecological vulnerability to fire; defined as the degree to which an ecosystem is susceptible to, and unable to cope with, adverse effects of fire (provided a fire occurs). Given the predicted climatic changes for the region, it is urgent to validate spatially explicit tools for assessing this vulnerability in order to support the design of new fire prevention and restoration strategies. This work presents an innovative GIS-based modelling approach to evaluate the ecological vulnerability to fire of an ecosystem, considering its main components (soil and vegetation) and different time scales. The evaluation was structured in three stages: short-term (focussed on soil degradation risk), medium-term (focussed on changes in vegetation), and coupling of the short- and medium-term vulnerabilities. The model was implemented in two regions: Aragón (inland North-eastern Spain) and Valencia (eastern Spain). Maps of the ecological vulnerability to fire were produced at a regional scale. We partially validated the model in a study site combining two complementary approaches that focused on testing the adequacy of model’s predictions in three ecosystems, all very common in fire-prone landscapes of eastern Spain: two shrublands and a pine forest. Both approaches were based on the comparison of model’s predictions with values of NDVI (Normalized Difference Vegetation Index), which is considered a good proxy for green biomass. Both methods showed that the model’s performance is satisfactory when applied to the three selected vegetation types. 相似文献
4.
Moore SA Wallington TJ Hobbs RJ Ehrlich PR Holling CS Levin S Lindenmayer D Pahl-Wostl C Possingham H Turner MG Westoby M 《Environmental management》2009,43(1):17-27
Current ecological thinking emphasizes that systems are complex, dynamic, and unpredictable across space and time. What is the diversity in interpretation of these ideas among today’s ecologists, and what does this mean for environmental management? This study used a Policy Delphi survey of ecologists to explore their perspectives on a number of current topics in ecology. The results showed general concurrence with nonequilibrium views. There was agreement that disturbance is a widespread, normal feature of ecosystems with historically contingent responses. The importance of recognizing multiple levels of organization and the role of functional diversity in environmental change were also widely acknowledged. Views differed regarding the predictability of successional development, whether “patchiness” is a useful concept, and the benefits of shifting the focus from species to ecosystem processes. Because of their centrality to environmental management, these different views warrant special attention from both managers and ecologists. Such divergence is particularly problematic given widespread concerns regarding the poor linkages between science (here, ecology) and environmental policy and management, which have been attributed to scientific uncertainty and a lack of consensus among scientists, both jeopardizing the transfer of science into management. Several suggestions to help managers deal with these differences are provided, especially the need to interpret broader theory in the context of place-based assessments. The uncertainty created by these differences requires a proactive approach to environmental management, including clearly identifying environmental objectives, careful experimental design, and effective monitoring. 相似文献
5.
Preston BL 《Environmental management》2002,29(3):311-323
Understanding toxicant effects at higher levels of biological organization continues to be a challenge in ecotoxicology and
ecological risk assessment. This is due in part to a tradition in ecotoxicology of considering the direct effects of toxicants
on a limited number of model test species. However, the indirect effects of toxicity may be a significant factor influencing
the manner in which ecosystem structure and function respond to anthropogenic stressors. Subsequently, failure to incorporate
indirect effects into risk assessment paradigms may be a significant source of uncertainty in risk estimates. The current
paper addresses the importance of indirect effects in an ecotoxicological context. Laboratory, mesocosm, and whole ecosystem
research into indirect effects is reviewed. The implications of indirect effects for ecological risk assessment and potential
areas of profitable future research are also discussed. 相似文献
6.
7.
Mark S. Wipfli John S. Richardson Robert J. Naiman 《Journal of the American Water Resources Association》2007,43(1):72-85
Abstract: Headwater streams make up a large proportion of the total length and watershed area of fluvial networks, and are partially characterized by the large volume of organic matter (large wood, detritus, and dissolved organic matter) and invertebrate inputs from the riparian forest, relative to stream size. Much of those inputs are exported to downstream reaches through time where they potentially subsidize river communities. The relative rates, timing, and conversion processes that carry inputs from small streams to downstream reaches are reasonably well quantified. For example, larger particles are converted to smaller particles, which are more easily exported. Also, dissolved organic matter and surface biofilms are converted to larger particles which can be more easily intercepted by consumers. However, the quality of these materials as it affects biological activity downstream is not well known, nor is the extent to which timing permits biological use of those particles. These ecological unknowns need to be resolved. Further, land uses may disrupt and diminish material transport to downstream reaches by removing sources (e.g., forest harvest), by affecting transport and decomposition processes (e.g., flow regulation, irrigation, changes in biotic communities), and by altering mechanisms of storage within headwaters (e.g., channelization). We present conceptual models of energy and nutrient fluxes that outline small stream processes and pathways important to downstream communities, and we identify informational gaps that, if filled, could significantly advance the understanding of linkages between headwater streams and larger rivers. The models, based on empirical evidence and best professional judgment, suggest that navigable waters are significantly influenced by headwater streams through hydrological and ecological connectivities, and land use can dramatically influence these natural connectivities, impacting downstream riverine ecosystems. 相似文献
8.
Ian C. Laurie 《Journal of Environmental Planning and Management》1983,26(2):89-98
The United Kingdom offers some of the finest designed parks and garden landscapes in the world and, whilst there is a wide range of skills and a wealth of literature on the subject, there is little evidence of official effort to systematically record historic sites. This, it is argued, is a factor in the continuing decline of many examples. This paper records an attempt at a comprehensive examination of one county — Cheshire — begun in 1970. The method is described and the results discussed in some detail. Some suggestions are put forward for improvements to official incentives for site owners. 相似文献
9.
Nick Hanley 《Journal of Environmental Planning and Management》1996,39(2):255-272
A common assumption in the economic valuation of the environment is that environmental resources can essentially be treated identically to produced goods and services in estimating welfare measures. The most critical aspect of this assumption in this regard is that individuals are willing to trade-off environmental quality changes in exchange for changes in their income. In this paper, we briefly review some of the conceptual arguments over this issue, and existing empirical evidence, before presenting the results of a new pilot study which addresses some of the possible problems in viewing the environment in this fashion. 相似文献
10.
RONALD R. SCHNABEL JOHN A. SHAFFER WILLIAM L. STOUT LEONARD F. CORNISH 《Environmental management》1997,21(2):283-290
/ Denitrification in riparian ecosystems can reduce the amount ofnitrogen transported from farm fields to streams. In this study, we examinedenitrification in four riparian ecosystems common to the Valley and Ridgephysiographic province in Pennsylvania, USA. The sites exhibit differentvegetation, are underlain by different rock types, and are downgradient offarm fields. Mean site denitrification rates ranging from 0.6 to 1.9 &mgr;gN/kg soil/day were measured using intact core incubation techniques. Thethree riparian sites covered with grass each exhibited greaterdenitrification rates than the wooded site. Denitrification rate wascorrelated with moisture content but not with nitrate-N or organic carboncontents. Denitrification rates were greatest near the soil surface and atpositions nearest the stream. Rates decreased uniformly with distance awayfrom the stream and also with depth in the soil for each site. While patternsof nitrate-N, moisture, and organic carbon content differ among the sites,their combined effects on denitrification support the observed, consistentdenitrification rate pattern.KEY WORDS: Denitrification; Riparian ecosystems 相似文献
11.
From Bathymetry to Bioshields: A Review of Post-Tsunami Ecological Research in India and its Implications for Policy 总被引:1,自引:0,他引:1
Nibedita Mukherjee Farid Dahdouh-Guebas Vena Kapoor Rohan Arthur Nico Koedam Aarthi Sridhar Kartik Shanker 《Environmental management》2010,46(3):329-339
More than half a decade has passed since the December 26th 2004 tsunami hit the Indian coast leaving a trail of ecological,
economic and human destruction in its wake. We reviewed the coastal ecological research carried out in India in the light
of the tsunami. In addition, we also briefly reviewed the ecological research in other tsunami affected countries in Asia
namely Sri Lanka, Indonesia, Thailand and Maldives in order to provide a broader perspective of ecological research after
tsunami. A basic search in ISI Web of Knowledge using keywords “tsunami” and “India” resulted in 127 peer reviewed journal
articles, of which 39 articles were pertaining to ecological sciences. In comparison, Sri Lanka, Indonesia, Thailand and Maldives
had, respectively, eight, four, 21 and two articles pertaining to ecology. In India, bioshields received the major share of
scientific interest (14 out of 39) while only one study (each) was dedicated to corals, seagrasses, seaweeds and meiofauna,
pointing to the paucity of research attention dedicated to these critical ecosystems. We noted that very few interdisciplinary
studies looked at linkages between pure/applied sciences and the social sciences in India. In addition, there appears to be
little correlation between the limited research that was done and its influence on policy in India. This review points to
gap areas in ecological research in India and highlights the lessons learnt from research in other tsunami-affected countries.
It also provides guidance on the links between science and policy that are required for effective coastal zone management. 相似文献
12.
Ferng JJ 《Environmental management》2007,40(6):913-925
Freshwater is necessary to economic activity, and humans depend on goods and services generated by water-dependent ecosystems.
However, national freshwater management usually focuses on direct use of domestic freshwater. With an increasing scarcity
of freshwater, attention has turned to two indirect uses of freshwater by humans. The first indirect use is freshwater used
by foreign countries when producing products for export. The second use is freshwater required by local ecosystems: human
survival and development depend on goods and services generated in these ecosystems. This work adopted Taiwan as a case study.
In addition to two widely recognized ecosystem freshwater demands, evapotranspiration and reversed river flow, this study
suggests that freshwater is a constituent of some abiotic components, such as groundwater in aquifers, because excessive withdrawal
has already caused significant land subsidence in Taiwan. Moreover, the estimated results show that Taiwan’s net imports of
freshwater through trade amounts to approximately 25% of its total freshwater use for economic production. Integrating industrial
policy, trade policy, and national freshwater management is a useful approach for developing strategies to limit the growing
use of freshwater in Taiwan. Policy implications are then developed by further analyzing withdrawal sources of freshwater
(domestic and foreign) for supporting economic production in Taiwan and identifying the factors (domestic final demand and
export) driving freshwater-intensive products. 相似文献
13.
Ecosystems, though impacted by global environmental change, can also contribute to the adaptation and mitigation of such large
scale changes. Therefore, sustainable ecosystem management is crucial in reaching a sustainable future for the biosphere.
Based on the published literature and publicly accessible data, this paper discussed the status and trends of forest, grassland,
and wetland ecosystems in China that play important roles in the ecological integrity and human welfare of the nation. Ecological
degradation has been observed in these ecosystems at various levels and geographic locations. Biophysical (e.g., climate change)
and socioeconomic factors (e.g., intensive human use) are the main reasons for ecosystem degradation with the latter factors
serving as the dominant driving forces. The three broad categories of ecosystems in China have partially recovered from degradation
thanks to large scale ecological restoration projects implemented in the last few decades. China, as the largest and most
populated developing nation, still faces huge challenges regarding ecosystem management in a changing and globalizing world.
To further improve ecosystem management in China, four recommendations were proposed, including: (1) advance ecosystem management
towards an application-oriented, multidisciplinary science; (2) establish a well-functioning national ecological monitoring
and data sharing mechanism; (3) develop impact and effectiveness assessment approaches for policies, plans, and ecological
restoration projects; and (4) promote legal and institutional innovations to balance the intrinsic needs of ecological and
socioeconomic systems. Any change in China’s ecosystem management approach towards a more sustainable one will benefit the
whole world. Therefore, international collaborations on ecological and environmental issues need to be expanded. 相似文献
14.
Richard T. T. Forman Bjorn Reineking Anna M. Hersperger 《Environmental management》2001,29(6):782-800
An extensive road system with rapidly increasing traffic produces diverse ecological effects that cover a large land area. Our objective was to evaluate the effect of roads with different traffic volumes on surrounding avian distributions, and its importance relative to other variables. Grassland bird data (5 years) for 84 open patches in an outer suburban/rural landscape near Boston were analyzed relative to: distance from roads with 3000–8000 to >30,000 vehicles/day; open-habitat patch size; area of quality microhabitat within a patch; adjacent land use; and distance to other open patches. Grassland bird presence and regular breeding correlated significantly with both distance from road and habitat patch size. Distance to nearest other open patch, irrespective of size, was not significant. Similarly, except for one species, adjacent land use, in this case built area, was not significant. A light traffic volume of 3000–8000 vehicles/day (local collector street here) had no significant effect on grassland bird distribution. For moderate traffic of 8000–15,000 (through street), there was no effect on bird presence although regular breeding was reduced for 400 m from a road. For heavier traffic of 15,000–30,000 (two-lane highway), both bird presence and breeding were decreased for 700 m. For a heavy traffic volume of ≥30,000 vehicles/day (multilane highway), bird presence and breeding were reduced for 1200 m from a road. The results suggest that avian studies and long-term surveys near busy roads may be strongly affected by traffic volume or changes in volume. We conclude that road ecology, especially the effects extending outward >100 m from roads with traffic, is a sine qua non for effective land-use and transportation policy. 相似文献
15.
2006年12月、2007年1—4月对湛江市寸金公园的鸟类资源状况进行了初步的研究,共记录到鸟类16种,隶属4目10科。其中,雀形目鸟类最多,共7科11种,约占总数的69%;其次为佛法僧目1科2种,约占总数的12.5%;鸡形目和鹃形目各1科1种,约占总数的6.25%。其中有国家Ⅱ级保护鸟类1种,占总数的6.25%。此外,属国家林业局发布的"国家重点保护的有益、有经济价值或有科学研究价值的动物"的鸟类7种,占总数的43.75%;被纳入省级重点保护鸟类的有2种,占总数12.6%;被纳入中澳候鸟协定鸟类的有1种,占总数的6.25%。 相似文献
16.
Joshua Farley David Batker Isabel de la Torre Tom Hudspeth 《Environmental management》2010,45(1):39-51
Humans are rapidly depleting critical ecosystems and the life support functions they provide, increasing the urgency of developing
effective conservation tools. Using a case study of the conversion of mangrove ecosystems to shrimp aquaculture, this article
describes an effort to develop a transdisciplinary, transinstitutional approach to conservation that simultaneously trains
future generations of environmental problem solvers. We worked in close collaboration with academics, non-government organizations,
local government and local communities to organize a workshop in Puerto Princesa, Palawan, Philippines. The primary objectives
of the workshop were to: (1) train participants in the basic principles of ecological economics and its goals of sustainable
scale, just distribution and efficient allocation; (2) learn from local community stakeholders and participating scientists
about the problems surrounding conversion of mangrove ecosystems to shrimp aquaculture; (3) draw on the skills and knowledge
of all participants to develop potential solutions to the problem; and (4) communicate results to those with the power and
authority to act on them. We found that the economic and ecological benefits of intact mangroves outweigh the returns to aquaculture.
Perversely, however, private property rights to mangrove ecosystems favor inefficient, unjust and unsustainable allocation
of the resource—a tragedy of the non-commons. We presented the workshop results to the press and local government, which shut
down the aquaculture ponds to conserve the threatened ecosystem. Effective communication to appropriate audiences was essential
for transforming research into action. Our approach is promising and can be readily applied to conservation research and advocacy
projects worldwide, but should be improved through adaptive management—practitioners must continually build on those elements
that work and discard or improve those that fail. 相似文献
17.
Chapple RS Ramp D Bradstock RA Kingsford RT Merson JA Auld TD Fleming PJ Mulley RC 《Environmental management》2011,48(4):659-674
Effective management of large protected conservation areas is challenged by political, institutional and environmental complexity
and inconsistency. Knowledge generation and its uptake into management are crucial to address these challenges. We reflect
on practice at the interface between science and management of the Greater Blue Mountains World Heritage Area (GBMWHA), which
covers approximately 1 million hectares west of Sydney, Australia. Multiple government agencies and other stakeholders are
involved in its management, and decision-making is confounded by numerous plans of management and competing values and goals,
reflecting the different objectives and responsibilities of stakeholders. To highlight the complexities of the decision-making
process for this large area, we draw on the outcomes of a recent collaborative research project and focus on fire regimes
and wild-dog control as examples of how existing knowledge is integrated into management. The collaborative research project
achieved the objectives of collating and synthesizing biological data for the region; however, transfer of the project’s outcomes
to management has proved problematic. Reasons attributed to this include lack of clearly defined management objectives to
guide research directions and uptake, and scientific information not being made more understandable and accessible. A key
role of a local bridging organisation (e.g., the Blue Mountains World Heritage Institute) in linking science and management
is ensuring that research results with management significance can be effectively transmitted to agencies and that outcomes
are explained for nonspecialists as well as more widely distributed. We conclude that improved links between science, policy,
and management within an adaptive learning-by-doing framework for the GBMWHA would assist the usefulness and uptake of future
research. 相似文献
18.
19.
The Collaborative Forest Landscape Restoration Program (CFLRP), established in 2009, encourages collaborative landscape scale ecosystem restoration efforts on United States Forest Service (USFS) lands. Although the USFS employees have experience engaging in collaborative planning, CFLRP requires collaboration in implementation, a domain where little prior experience can be drawn on for guidance. The purpose of this research is to identify the ways in which CFLRP’s collaborative participants and agency personnel conceptualize how stakeholders can contribute to implementation on landscape scale restoration projects, and to build theory on dynamics of collaborative implementation in environmental management. This research uses a grounded theory methodology to explore collaborative implementation from the perspectives and experiences of participants in landscapes selected as part of the CFLRP in 2010. Interviewees characterized collaborative implementation as encompassing three different types of activities: prioritization, enhancing treatments, and multiparty monitoring. The paper describes examples of activities in each of these categories and then identifies ways in which collaborative implementation in the context of CFLRP (1) is both hindered and enabled by overlapping legal mandates about agency collaboration, (2) creates opportunities for expanded accountability through informal and relational means, and, (3) creates feedback loops at multiple temporal and spatial scales through which monitoring information, prioritization, and implementation actions shape restoration work both within and across projects throughout the landscape creating more robust opportunities for adaptive management. 相似文献
20.
Over the next half century the human population is expected to grow rapidly, resulting in the conversion of rural areas into
cities. Wetlands in these regions are therefore under threat, even though they have important ecosystem services and functions.
Many obligate marsh-nesting birds in North America have shown declines over the past 40 years, and it is important to evaluate
marsh bird community response to increased urbanization. We surveyed 20 coastal marshes in southern Ontario, Canada, and found
that obligate marsh-nesting birds preferred rural over urban wetlands, generalist marsh-nesting birds showed no preference,
while synanthropic species showed a trend towards increased richness and abundance in urban marshes. The Index of Marsh Bird
Community Integrity (IMBCI) was calculated for each wetland and we found significantly higher scores in rural compared to
urban wetlands. The presence of a forested buffer surrounding the marsh was not an important factor in predicting the distribution
of generalists, obligates, synanthropic species, or the IMBCI. More isolated marshes had a lower species richness of obligate
marsh-nesters and a lower IMBCI than less isolated marshes. Based on our results, we recommend that urban land use is not
the dominant land use within 1000 m from any wetland, as it negatively affects the abundance and richness of obligate marsh-nesters,
and the overall integrity of the avian community. We also recommend that all existing wetlands be conserved to mitigate against
isolation effects and to preserve biodiversity. 相似文献