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161.
Observing the full range of climate change impacts at the local scale is difficult. Predicted rates of change are often small relative to interannual variability, and few locations have sufficiently comprehensive long-term records of environmental variables to enable researchers to observe the fine-scale patterns that may be important to understanding the influence of climate change on biological systems at the taxon, community, and ecosystem levels. We examined a 50-year meteorological and hydrological record from the Hubbard Brook Experimental Forest (HBEF) in New Hampshire, an intensively monitored Long-Term Ecological Research site. Of the examined climate metrics, trends in temperature were the most significant (ranging from 0.7 to 1.3 °C increase over 40–50 year records at 4 temperature stations), while analysis of precipitation and hydrologic data yielded mixed results. Regional records show generally similar trends over the same time period, though longer-term (70–102 year) trends are less dramatic. Taken together, the results from HBEF and the regional records indicate that the climate has warmed detectably over 50 years, with important consequences for hydrological processes. Understanding effects on ecosystems will require a diversity of metrics and concurrent ecological observations at a range of sites, as well as a recognition that ecosystems have existed in a directionally changing climate for decades, and are not necessarily in equilibrium with the current climate.  相似文献   
162.
After providing a statistical survey of Japanese direct investment in the US fishing industry, and a historical background of Japanese-US fishing relations, the author examines the statutory regulation of foreign direct investment (FDI) in the fishing industry. She then discusses international practice and restrictions on FDI, the recent response of Congress in view of the Two-Hundred-Mile Law, and the issue of protectionism and the competitive position of the US fishing industry.  相似文献   
163.
164.
Delegates to UNCLOS III, in drafting a charter for a kind of international institution to control the resources of the deep seabed constituting the ‘common heritage of mankind’, have had to face and find a way of reconciling the antagonism between the “sovereign equality of states’ and the proportional representation of economic interests. This article briefly describes the manner in which this has been achieved.  相似文献   
165.
Tools for assessing and communicating salt marsh condition are essential to guide decisions aimed at maintaining or restoring ecosystem integrity and services. Multimetric indices (MMIs) are increasingly used to provide integrated assessments of ecosystem condition. We employed a theory-based approach that considers the multivariate relationship of metrics with human disturbance to construct a salt marsh MMI for five National Parks in the northeastern USA. We quantified the degree of human disturbance for each marsh using the first principal component score from a principal components analysis of physical, chemical, and land use stressors. We then applied a metric selection algorithm to different combinations of about 45 vegetation and nekton metrics (e.g., species abundance, species richness, and ecological and functional classifications) derived from multi-year monitoring data. While MMIs derived from nekton or vegetation metrics alone were strongly correlated with human disturbance (r values from ?0.80 to ?0.93), an MMI derived from both vegetation and nekton metrics yielded an exceptionally strong correlation with disturbance (r = ?0.96). Individual MMIs included from one to five metrics. The metric-assembly algorithm yielded parsimonious MMIs that exhibit the greatest possible correlations with disturbance in a way that is objective, efficient, and reproducible.  相似文献   
166.
National boundaries and border cities have been transformed globally. This is partly due to neoliberal globalisation, the continuous formation of a ‘borderless world’ and partly to the global ‘war on terror’. Darwin, the capital city of the Northern Territory (NT), is on the northern coast of Australia, bordering its overseas Asian neighbours. Far away from the main Australian population centres in the south, the city grows slowly, relying mainly on Australian government investments, infrastructure, and the incorporation of defence programs in the north. The rise of Asia, as well as Australia's increasing economic reliance on Asia, has created new opportunities for Darwin's growth. The development of Asian economies has resulted in growing global investment in resource extraction in NT. Asia, though, has been seen as a key threat in the modern history of Australia. This national sensitivity is underpinned by the global ‘war on terror’ in which Australia is deeply involved. Australia has tight border control regimes and a growing military presence on the northern border area. This paper examines how these co-existing but contradictory dynamics have reshaped the urban development of Darwin City. The consequential social and spatial patterns are identified and discussed.  相似文献   
167.
Cumming  Gabriel  Campbell  Lisa  Norwood  Carla  Ranger  Sue  Richardson  Peter  Sanghera  Amdeep 《GeoJournal》2021,87(2):209-221

Stakeholders in natural resource management decisions are also multifaceted individuals and members of communities; as such, they bring complex histories, experiences, values, aspirations, and relationships to public participation processes. When these processes fail to take this social context into account, multiple problems can result, including a perceived lack of process trustworthiness; perceived focus on issues that seem immaterial or irrelevant; failure to equitably represent and take account of diverse voices; and failure to engage participants in productive dialogue. In this article we evaluate the Community Voice Method (CVM) as a way of addressing those problems by better situating public participation in place. CVM is a mixed-method approach to public participation in which stakeholders are interviewed and the interview data is presented through a film, which is then screened at public meetings to catalyze dialogue. We draw on 14 years of CVM projects addressing natural resource management issues in the United States, the United Kingdom, and the Caribbean. Through an overview of nine projects and their results, and more in-depth consideration of three, we elucidate how this method fosters trustworthy, relevant, representative, and productive public participation that has resulted in community capacity-building, institutional capacity-building, and stakeholder-guided policymaking.

  相似文献   
168.
Three quarters of the global human population will live in coastal areas in the coming decades and will continue to develop these areas as population density increases. Anthropogenic stressors from this coastal development may lead to fragmented habitats, altered food webs, changes in sediment characteristics, and loss of near-shore vegetated habitats. Seagrass systems are important vegetated estuarine habitats that are vulnerable to anthropogenic stressors, but provide valuable ecosystem functions. Key to maintaining these habitats that filter water, stabilize sediments, and provide refuge to juvenile animals is an understanding of the impacts of local coastal development. To assess development impacts in seagrass communities, we surveyed 20 seagrass beds in lower Chesapeake Bay, VA. We sampled primary producers, consumers, water quality, and sediment characteristics in seagrass beds, and characterized development along the adjacent shoreline using land cover data. Overall, we could not detect effects of local coastal development on these seagrass communities. Seagrass biomass varied only between sites, and was positively correlated with sediment organic matter. Epiphytic algal biomass and epibiont (epifauna and epiphyte) community composition varied between western and eastern regions of the bay. But, neither eelgrass (Zostera marina) leaf nitrogen (a proxy for integrated nitrogen loading), crustacean grazer biomass, epifaunal predator abundance, nor fish and crab abundance differed significantly among sites or regions. Overall, factors operating on different scales appear to drive primary producers, seagrass-associated faunal communities, and sediment properties in these important submerged vegetated habitats in lower Chesapeake Bay.  相似文献   
169.
The behavior of a number of solar wind, radiation belt, auroral and geomagnetic parameters is examined during the recent extended solar minimum and previous solar cycles, covering the period from January 1972 to July 2010. This period includes most of the solar minimum between Cycles 23 and 24, which was more extended than recent solar minima, with historically low values of most of these parameters in 2009. Solar rotational periodicities from 5 to 27 days were found from daily averages over 81 days for the parameters. There were very strong 9-day periodicities in many variables in 2005?–?2008, triggered by recurring corotating high-speed streams (HSS). All rotational amplitudes were relatively large in the descending and early minimum phases of the solar cycle, when HSS are the predominant solar wind structures. There were minima in the amplitudes of all solar rotational periodicities near the end of each solar minimum, as well as at the start of the reversal of the solar magnetic field polarity at solar maximum (~?1980, ~?1990, and ~?2001) when the occurrence frequency of HSS is relatively low. Semiannual equinoctial periodicities, which were relatively strong in the 1995?–?1997 solar minimum, were found to be primarily the result of the changing amplitudes of the 13.5- and 27-day periodicities, where 13.5-day amplitudes were better correlated with heliospheric daily observations and 27-day amplitudes correlated better with Earth-based daily observations. The equinoctial rotational amplitudes of the Earth-based parameters were probably enhanced by a combination of the Russell-McPherron effect and a reduction in the solar wind-magnetosphere coupling efficiency during solstices. The rotational amplitudes were cross-correlated with each other, where the 27-day amplitudes showed some of the weakest cross-correlations. The rotational amplitudes of the >?2 MeV radiation belt electron number fluxes were progressively weaker from 27- to 5-day periods, showing that processes in the magnetosphere act as a low-pass filter between the solar wind and the radiation belt. The A p/K p magnetic currents observed at subauroral latitudes are sensitive to proton auroral precipitation, especially for 9-day and shorter periods, while the A p/K p currents are governed by electron auroral precipitation for 13.5- and 27-day periodicities.  相似文献   
170.
Abstract

The type of remotely sensed imagery best suited for natural hazards analysis is largely dependent on the geographic size and discreteness of the hazard in question. Some forms of imagery that are appropriate for analyses of spatially fixed, relatively fine‐scale hazards are inappropriate for use with geographically widespread and transient hazards, and vice versa. In this paper we utilize one study area, Waterton‐Glacier International Peace Park (Canada and USA), and two natural hazard types (snow avalanches and forest fires), to illustrate how these remote sensing principles can be presented to students of natural hazards. We also address the issue of familiarity, or lack thereof, that students have with different images from a variety of platforms.  相似文献   
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