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261.
This article describes a process of developing socio-cultural indicators to support local and regional decision-making for eco-efficiency. Although eco-efficiency is calculated using environmental and economic variables, decisions on local and regional levels cannot ignore the socio-cultural impacts. The indicators were developed by a participatory process that was based on involvement and empowerment of local actors. The process ensured policy relevance and meaningful indicators and advanced their future use in the decision-making. 相似文献
262.
The effectiveness of recycling depends upon efficient functioning of secondary material markets. This paper focus on the role that price volatility can play in slowing investment and market development. However, a statistical analysis of the relative volatility of secondary and primary material prices does not confirm the widely-held belief that relative price volatility is higher in secondary than in primary materials, at least at national levels.An econometric estimation of the determinants of plastic recovery volumes in Seattle contributes to the literature in four ways: the use of monthly (as opposed to annual) data; the use of local (as opposed to national) data; the use of an explanatory variable to reflect price volatility; and, the focus on plastics, which have not been examined previously. Some tentative conclusions can be made: the results generally support the principal hypothesis that price volatility has a negative effect on recovery of secondary materials; in addition, and consistent with previous studies, price elasticities are low and insignificant; and finally, policy factors are clearly important. The concluding section treats the economic and policy implications of market inefficiency in secondary material markets. 相似文献
263.
264.
Understanding the demography and function of biotope-forming seaweed species is of great importance for the conservation of
the target species itself, as well as its associated organisms. The brown seaweed Ascophyllum nodosum is fundamental for the functioning of coastal marine ecosystems in the North Atlantic. In this study, we use a data-based
size-classified matrix model to investigate the temporal and spatial variability in demography, and the environment-specific
stochastic sensitivity and elasticity, of two A. nodosum populations, one in western Sweden and one on the Isle of Man in the Irish Sea. A significant difference between the two
populations was that the Swedish population had comparably low and more variable stochastic population growth rate (λ
s). This pattern was partly explained by the relatively high and varying mortality rates during extreme ice-years in Sweden,
and by the lower survival of small individuals during all years. There were also fewer large individuals in Sweden due to
lower transitions to the larger size-classes and higher probability of shrinkage. Sensitivities were analogous in the two
populations, and showed a high selection pressure for increased individual growth. Elasticities were also similar, with the
exception that survival of the smallest individuals (i.e., transition a
1,1), had a higher elasticity on the Isle of Man. Overall, the stochastic growth rate (λ
s) was most sensitive to proportional changes in loop- (i.e., survival within size-class) and, to some extent, growth-transitions
in both study areas. These results show that structurally and demographically diverging A. nodosum populations may be similarly sensitive to changes in vital rates. This, in turn, indicates a plastic life history of A. nodosum that may cope with large environmental variability. The results further suggest that environmental change affecting the survival
or growth of the larger, reproductive A. nodosum individuals could have severe and regional effects on the abundance and biomass of this species, with potential negative
effects on the biodiversity of the associated communities. 相似文献
265.
Wanjun Liu Amar K. Mohanty Per Askeland Lawrence T. Drzal Manjusri Misra 《Journal of Polymers and the Environment》2008,16(3):177-182
Chemical modification of soy protein with monomers such as maleic anhydride, glycidyl methacrylate and styrene was accomplished
using reactive extrusion technology. Thermal and mechanical properties of the modified soy protein plastics were characterized
with differential scanning calorimetry (DSC), a dynamic mechanical analyzer (DMA) and a United Testing System load frame.
It was found that the denaturation temperature and the glass transition temperature of soy protein plastic changed. In addition,
the tensile properties of modified soy protein plastic improved. Attenuated total reflection Fourier transform infrared (ATR-FTIR)
and X-ray photoelectron spectroscopy (XPS) were used to characterize the structure of modified soy proteins. A suggestion
of the interaction between soy protein and functional group in functional polymers is given. Through the in-situ interaction
between the polymer and soy protein plastic, the mechanical properties of the soy protein plastic can be adjusted and controlled. 相似文献
266.
Per?ArnqvistEmail authorView authors OrcID profile
return OK on get Christian?Bigler Ingemar?Renberg Sara?Sj?stedt?de?Luna 《Environmental and Ecological Statistics》2016,23(4):513-529
Annually laminated (varved) lake sediments constitutes excellent environmental archives, and have the potential to play an important role for understanding past seasonal climate with their inherent annual time resolution and within-year seasonal patterns. We propose to use functional data analysis methods to extract the relevant information with respect to climate reconstruction from the rich but complex information in the varves, including the shapes of the seasonal patterns, the varying varve thickness, and the non-linear sediment accumulation rates. In particular we analyze varved sediment from lake Kassjön in northern Sweden, covering the past 6400 years. The properties of each varve reflect to a large extent weather conditions and internal biological processes in the lake the year that the varve was deposited. Functional clustering is used to group the seasonal patterns into different types, that can be associated with different weather conditions. The seasonal patterns were described by penalized splines and clustered by the k-means algorithm, after alignment. The observed (within-year) variability in the data was used to determine the degree of smoothing for the penalized spline approximations. The resulting clusters and their time dynamics show great potential for seasonal climate interpretation, in particular for winter climate changes. 相似文献
267.
Andreas Sundelöf Stuart R. Jenkins Carl J. Svensson Jane Delany Stephen J. Hawkins Per Åberg 《Marine Biology》2010,157(4):779-789
The importance of external and internal population processes in determining variation in reproductive output and variation
in population size were quantified with model simulations for open populations of the sequentially hermaphroditic limpet Patella vulgata using field data from the Isle of Man and South West Ireland. Cross-correlation analyses of model outputs and elasticity
analyses show that population dynamics are dominated by the effects of large females, and that recruitment adds little to
reproductive output. However, populations experiencing low but highly variable recruitment appear male limited and recruitment
pulses carrying young males into the population are correlated to reproductive output with a 2–5-year lag. We conclude that
pulses in recruitment can be a major structuring force in these limpet populations, but site-specific post-recruitment processes
will determine the relative importance of recruitment to population dynamics and the lag between recruitment and reproductive
output. 相似文献
268.
Multiple functions increase the importance of biodiversity for overall ecosystem functioning 总被引:4,自引:0,他引:4
Biodiversity is proposed to be important for the rate of ecosystem functions. Most biodiversity-ecosystem function studies, however, consider only one response variable at a time, and even when multiple variables are examined they are analyzed separately. This means that a very important aspect of biodiversity is overlooked: the possibility for different species to carry out different functions at any one time. We propose a conceptual model to explore the effects of species loss on overall ecosystem functioning, where overall functioning is defined as the joint effect of many ecosystem functions. We show that, due to multifunctional complementarity among species, overall functioning is more susceptible to species loss than are single functions. Modeled relationships between species richness and overall ecosystem functioning using five empirical data sets on monocultures reflected the range of effects of species loss on multiple functions predicted by the model. Furthermore, an exploration of the correlations across functions and the degree of redundancy within functions revealed that multifunctional redundancy was generally lower than single-function redundancy in these empirical data sets. We suggest that by shifting the focus to the variety of functions maintained by a diversity of species, the full importance of biodiversity for the functioning of ecosystems can be uncovered. Our results are thus important for conservation and management of biota and ecosystem services. 相似文献
269.
We provide algebraic simplifications for the redundancy analysis (RDA) eigenvalue and the canonical correspondence analysis (CCA) eigenvalue in the special case of permanent plots sampled twice. The indices for RDA and CCA are interrelated and are intuitively interpretable. These simplifications also apply to simple split-plot designs and to a balanced design with two independent samples. 相似文献
270.
When reproduction competes with the amount of resources available for survival during an unpredictable nonbreeding season, individuals should adopt a risk-sensitive regulation of their reproductive allocation. We tested this hypothesis on female reindeer (Rangifer tarandus), which face a trade-off between reproduction and acquisition of body reserves during spring and summer, with autumn body mass functioning as insurance against stochastic winter climatic severity. The study was conducted in a population consisting of two herds: one that received supplementary winter feeding for four years while the other utilized natural pastures. The females receiving additional forage allocated more to their calves. Experimental translocation of females between the herds was conducted to simulate two contrasting rapid alterations of winter conditions. When females receiving supplementary feeding were moved to natural pastures, they promptly reduced their reproductive allocation the following summer. However, when winter conditions were improved, females were reluctant to increase their reproductive allocation. This asymmetric response to improved vs. reduced winter conditions is consistent with a risk-averse adjustment in reproductive allocation. The ability of individuals to track their environment and the concordant risk-sensitive adjustment of reproductive allocation may render subarctic reindeer more resilient to climate change than previously supposed. 相似文献