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651.
Are Alaska-style citizen revenue distribution funds the solution to the resource curse in developing countries as their proponents conjecture? Unfortunately it appears not. First, it is questionable whether developing countries have the institutional capacity to implement and operate such funds successfully. Second, citizen funds are unlikely to have any substantial impact on governance and their macroeconomic effects are uncertain. Finally, as a comparative case study of the three natural resource-intensive economies that successfully steered clear of excessive real appreciation and crowding out of the non-minerals tradables sector—Botswana, Indonesia and Norway—shows, citizen funds are likely to carry detrimental indirect effects on the ability of governments to surmount the Dutch Disease. 相似文献
652.
Thomas M. Yanosky 《Journal of the American Water Resources Association》1984,20(2):241-250
ABSTRACT: Ash trees (Fraxinus americana L. and F. Pennsylvanica Marsh.) collected from the flood plain of the Potomac River near Washington, D.C., were studied for evidence of associations between known periods of above-average summer flows and changes in wood-growth anatomy. Concentric bands of latewood fibers with atypically large lumens and thin walls commonly developed in trees growing near the low-water channel. Discharge records indicate that roots of most trees with these “white rings” were flooded temporarily during the latewood-growth interval. Trees apparently were not damaged and a concomitant reduction of internal water stresses seems to have accelerated the rate of radial growth. The intra-ring position of anomalous fibers generally corresponded to the time of increased discharge within the estimated interval of latewood growth. Anomalous fibers occasionally formed in unflooded trees, but their position also coincided with episodes of increased discharge. The results of these studies may have applications for streamflow-reconstruction techniques where hydrologic data are incomplete or lacking. 相似文献
653.
Digital simulation models of radiocesium cycling in Turkey Oaks were developed from in situ 134Cs tagging studies. Predictions of 134Cs steady-state distribution for 3-, 4- and 5-compartment, donor-controlled models were compared with the estimated fallout 137Cs distribution as a measure of model validation; output from the 5-compartment model compared best. Sensitivity analysis demonstrated that Turkey Oak burden of 134Cs was equally sensitive to the output rate from the tree compartment and the availability of 134Cs for uptake (i.e., presence in the root zone) but not the rate of uptake by Turkey Oaks. Observed distribution and model predictions indicate that radiocesium is readily bioaccumulated by Turkey Oaks (~13% of the ecosystem burden) from the soil and is cycled within the sand hills—Turkey Oak ecosystem. 相似文献
654.
Environmental Vulnerability Indicators for Environmental Planning and Decision-Making: Guidelines and Applications 总被引:6,自引:0,他引:6
Environmental decision-making and policy-making at all levels refers necessarily to synthetic, approximate quantification
of environmental properties such as vulnerability, conservation status, and ability to recover after perturbation. Knowledge
of such properties is essential to informed decision-making, but their definition is controversial and their precise characterization
requires investments in research, modeling, and data collection that are only possible in the most developed countries. Environmental
agencies and governments worldwide have increasingly requested numerical quantification or semiquantitative ranking of such
attributes at the ecosystem, landscape, and country level. We do not have a theory to guide their calculation, in general
or specific contexts, particularly with the amount of resources usually available in such cases. As a result, these measures
are often calculated with little scientific justification and high subjectivity, and such doubtful approximations are used
for critical decision-making. This problem applies particularly to countries with weak economies, such as small island states,
where the most precious environmental resources are often concentrated.
This paper discusses frameworks for a “least disappointing,” approximate quantification of environmental vulnerability. After
a review of recent research and recent attempts to quantify environmental vulnerability, we discuss models and theoretical
frameworks for obtaining an approximate, standardizable vulnerability indicator of minimal subjectivity and maximum generality.
We also discuss issues of empirical testing and comparability between indicators developed for different environments. To
assess the state of the art, we describe an independent ongoing project developed in the South Pacific area and aimed to the
comparative evaluation of the vulnerability of arbitrary countries. 相似文献
655.
Foraging areas of king penguins from Macquarie Island in relation to a marine protected area 总被引:1,自引:0,他引:1
Twenty-three king penguins (Aptenodytes patagonicus) from Macquarie Island were tracked by satellite during the late incubation period in 1998–1999 to determine the overlap
of the foraging zone of king penguins with an area to be declared a marine protected area (MPA) near the island. While all
penguins left the colony in an easterly direction and traveled clockwise back to the island, three penguins foraged in the
northern parts of the general foraging area and stayed north of 56°S. The remaining 20 penguins ventured south and most crossed
59°S before returning to the island. The total foraging area was estimated to be 156,000 km2 with 36,500 km2 being most important (where penguins spent >150 hr in total). North-foraging penguins reached on average 331 ± 24 km from
the colony compared to 530 ± 76 km for the south-foraging penguins. The latter traveled an average total distance of 1313
± 176 km, while the northern foragers averaged 963 ± 166 km. Not only did the penguins spend the majority of their foraging
time within the boundaries of the proposed MPA, they also foraged chiefly within the boundaries of a highly protected zone.
Thus, the MPA is likely to encompass the foraging zone of king penguins, at least during incubation. 相似文献
656.
Conserving genetic diversity requires an assessment of the distribution of genetic variants in relation to patterns of land
use and environmental variation at a regional scale. This assessment requires a novel approach to integrating and analyzing
the genetic and environmental data across spatial scales. To explore the integration of genetic data with other geospatial
data sets, we developed a GIS-based approach for examining patterns of genetic diversity for several species of salamanders
in southern Appalachians. The genetic data, from allozyme surveys in the genetics literature, were integrated into a GIS database
along with related attributes including population identifications and spatial locations. Using existing geospatial data,
we classified sample locations as being either protected from anthropogenic disturbance (e.g., National Parks, Wilderness
Areas) or as unprotected (e.g., private lands, multiple-use lands in National Forests). We used multidimensional scaling of
allelic frequencies and contributions of populations to interpopulation differences in allelic richness to determine which
populations had genetic characteristics most different from other populations in the sample. Measures of genetic differentiation
were integrated into the GIS database to facilitate spatial analysis and visualization of the indices in relation to land
use. This approach was useful for both identification of populations with components of genetic variation that were not well
represented at protected sites and for identifying areas of species distributions where more genetic sampling would be necessary
to make informed management decisions. Our approach could be readily adapted for use by managers and geneticists working with
other species and types of genetic markers. 相似文献
657.
Declines in salmon stocks and general watershed health in Washington State, USA, have led to an increase in stream restoration
and enhancement projects initiated throughout the state. The increasing number of projects has also raised questions regarding
the monitoring of these efforts. Project managers receiving hydraulic project approvals (HPAs) were surveyed to determine
whether monitoring was taking place on their projects. About half the project managers surveyed reported the collection of
baseline data and the use of biological, physical, chemical, or other water quality measures for their projects. Of those
who reported collection of monitoring data, only 18% indicated that monitoring was required. Respondents were also asked to
rank the importance of various project goals on a Likert scale. Project managers with projects focusing on “engineering” goals
(e.g., roadbed stabilization) were less likely than other project managers to collect baseline monitoring data. Project managers
with projects focusing on “restoration/ecological” or “fisheries” goals were more likely than other project managers to collect
monitoring measures. Although monitoring appears to be taking place in slightly more than half of the projects surveyed, the
nature of the data collected varies widely across projects, and in most cases the monitoring effort is voluntary. This suggests
that project sponsors, funders, and managers must consider the issues involved in requiring appropriate monitoring, establishing
standardized monitoring guidelines, the time frames in which to monitor, providing other incentives for conducting monitoring,
and ensuring adequate funding for monitoring efforts. 相似文献
658.
Maintaining Volunteer Commitment to Local Watershed Initiatives 总被引:1,自引:0,他引:1
Australia's Landcare program is advanced as a successful international example of local watershed groups and governments working
together to improve natural resource management. One of the aspects considered critical in the success of watershed groups
is engaging widespread participation. This paper draws on two regional surveys that explored burnout, or loss of engagement,
among Landcare participants in the state of Victoria using the Maslach Burnout Inventory. Survey findings indicated that a
large proportion of respondents were experiencing high burnout in terms of low personal accomplishment and suggested that
there was potential for burnout to increase. The authors suggest that the expectations of watershed groups must be based around
a realistic assessment of the capacity for volunteer groups to deliver improved environmental and social outcomes. 相似文献
659.
Diem JE 《Environmental management》2002,29(3):373-384
This paper examines possible ozone-induced foliar injury to ponderosa pine areas in the Rincon Mountains of southern Arizona
from 1972 to 1992. Spatiotemporal differences in a satellite-derived vegetation index (VI) are examined with respect to antecedent
moisture conditions, temporal variations in ozone exposure levels, and measured foliar injury values from 1985. Seasonal ozone
exposure levels (SUM60 and W126) increased from 1982 to 1998 and were significantly correlated (r = 0.49 and 0.53, α= 0.05) with annual population totals in the Tucson area. Extensive masking of satellite images from 1972, 1986,
and 1992 resulted in two optimal change detection areas, with one site, TVWMica, exposed mostly to the Tucson air pollution
plume, while the other site, EMica, was more protected from Tucson-derived pollution. An overall increase in VI from 1972
to 1992 at both sites appears to have been caused by an increase in moisture availability. Larger foliar injury values in
1985 were associated with a smaller increase in VI (i.e., a smaller increase in green leaf biomass) from 1972 to 1986. From
1972 to 1986 and from 1986 to 1992, VI values at TV/WMica increased at a slower rate compared to those at EMica. The reduced
increase in “green-up” may have been caused partially by ozone-induced foliar injury and resulting decreases in green leaf
biomass. However, these spatial differences in VI values may have also been caused by a number of other factors. Results nevertheless
reveal the strong possibility of distinct, topographically based, spatial variations in ozone-induced foliar injury within
the Rincons. 相似文献
660.
The effects of livestock grazing on selected riparian and stream attributes, water chemistry, and algal biomass were investigated
over a two-year period using livestock enclosures and by completing stream surveys in the Cypress Hills grassland plateau,
Alberta, Canada. Livestock enclosure experiments, partially replicated in three streams, comprised four treatments: (1) early
season livestock grazing (June–August), (2) late season livestock grazing (August–September), (3) all season grazing (June–September),
and (4) livestock absent controls. Livestock grazing significantly decreased streambank stability, biomass of riparian vegetation,
and the extent to which aquatic vegetation covered the stream channels compared with livestock-absent controls. Water quality
comparisons indicated significant differences among the four livestock grazing treatments in Battle and Graburn creeks but
not in Nine Mile Creek. In Graburn Creek, the concentration of total phosphorus in the all-season livestock grazing treatment
was significantly higher than that in the livestock-absent control, and the early season and late season grazing treatments.
Concentrations of soluble reactive phosphorus in the all-season livestock grazing treatment also exceeded that in livestock-absent
control. In contrast, differences in water quality variables in the remaining 22 comparisons (i.e., 22 of the total 24 comparisons)
were minor even when differences were statistically significant. Effects of livestock grazing on algal biomass were variable,
and there was no consistent pattern among creeks. At the watershed scale, spatial variation in algal biomass was related (P < 0.05) with concentrations of NO2
− + NO3
− and soluble reactive phosphorus in two of the four study creeks. Nutrient diffusing substrata experiments showed that algal
communities were either nitrogen-limited or not limited by nutrients, depending on stream and season. 相似文献