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441.
Use of Descriptors of Ecosystem Functioning for Monitoring a National Park Network: A Remote Sensing Approach 总被引:1,自引:0,他引:1
Baseline assessments and monitoring of protected areas are essential for making management decisions, evaluating the effectiveness
of management practices, and tracking the effects of global changes. For these purposes, the analysis of functional attributes
of ecosystems (i.e., different aspects of the exchange of matter and energy) has advantages over the traditional use of structural
attributes, like a quicker response to disturbances and the fact that they are easily monitored through remote sensing. In
this study, we described the spatiotemporal patterns of different aspects of the ecosystem functioning of the Spanish national
parks and their response to environmental changes between 1982 and 2006. To do so, we used the NOAA/AVHRR-GIMMS dataset of
the Normalized Difference Vegetation Index (NDVI), a linear estimator of the fraction of photosynthetic active radiation intercepted
by vegetation, which is the main control of carbon gains. Nearly all parks have significantly changed during the last 25 years:
The radiation interception has increased, the contrast between the growing and nongrowing seasons has diminished, and the
dates of maximum and minimum interception have advanced. Some parks concentrated more changes than others and the degree of
change varied depending on their different environmental conditions, management, and conservation histories. Our approach
identified reference conditions and temporal changes for different aspects of ecosystem functioning, which can be used for
management purposes of protected areas in response to global changes. 相似文献
442.
Papadopoulos F Parissopoulos G Papadopoulos A Zdragas A Ntanos D Prochaska C Metaxa I 《Environmental management》2009,43(1):135-143
Field research was carried out to assess the effects of the application of reclaimed municipal wastewater on rice cultivation
in Thessaloniki, Greece during a 2-year period (1999–2000). Effects on production cost, soil composition, and health risk
were examined. A randomized complete block design was used for the paddy field with three treatments and four replicates.
The treatments were (1) river irrigation water with N–P fertilization, (2) reclaimed wastewater irrigation with surface N
fertilization, and (3) reclaimed wastewater irrigation without fertilization. The results showed that the total production
cost decreased 8.8% and 11.9% by applying the second and third treatments, respectively, compared to the first treatment,
without significant differences in the agronomic and rice quality traits. Soil composition showed discrepancies between the
2 years and the three treatments, whereas the pathogens of the reclaimed wastewater and rice tissues posed a low human risk
when taking the needed precautions. 相似文献
443.
This article analyzes and carries out an econometric test of the explanatory power of economic and attitude variables for
occurrences of the nonnative signal crayfish in Swedish waters. Signal crayfish are a carrier of plague which threatens the
native noble crayfish with extinction. Crayfish are associated with recreational and cultural traditions in Sweden, which
may run against environmental preferences for preserving native species. Econometric analysis is carried out using panel data
at the municipality level with economic factors and attitudes as explanatory variables, which are derived from a simple dynamic
harvesting model. A log-normal model is used for the regression analysis, and the results indicate significant impacts on
occurrences of waters with signal crayfish of changes in both economic and attitude variables. Variables reflecting environmental
and recreational preferences have unexpected signs, where the former variable has a positive and the latter a negative impact
on occurrences of waters with signal crayfish. These effects are, however, counteracted by their respective interaction effect
with income. 相似文献
444.
Agri-environment programs aim to secure environmental and social stewardship services through payments to farmers. A critical
component of many agri-environment programs is an agri-environment index (AEI) used to quantify benefits and target investments.
An AEI will typically comprise multiple indicators, which are weighted and combined using a utility function, to measure the
benefit of investment options (e.g., projects, farms, regions). This article presents a review of AEIs with 11 case studies
from agri-environment programs in the United States, Australia, and the United Kingdom. We identify a generic procedure used
to define AEIs and explore the implications of alternative methodological approaches. We conclude that AEIs have become an
extremely important policy instrument and make suggestions for their improvement. 相似文献
445.
Yung-Ping Tseng Gerard T. Kyle C. Scott Shafer Alan R. Graefe Timothy A. Bradle Michael A. Schuett 《Environmental management》2009,43(3):496-507
Along with the growing boating population and the number of boats in use on limited inland waterways, boater expectations
of setting density, safety perceptions, and the associated impacts on their experience (e.g., satisfaction) are becoming increasingly
important. The primary purpose of this article was to explore a recreational boating crowding–satisfaction model derived from
previous work using safety and enjoyment as mediating variables. We also tested our crowding–satisfaction model among day
and overnight users. Our analysis revealed no significant difference between day and overnight users for any of the relationships
tested in our model. Our final model indicated as respondents’ expectations for seeing people increased along with their feelings
of being crowded, they were more inclined to consider the conditions on the lake as being unsafe. They were also more inclined
to indicate that the number of people they had seen on the lake detracted from their boating experience. Respondents’ satisfaction
was tied to their perceptions of crowding. Mediating variables illustrated that the relationship was conditioned by perceptions
of safety and enjoyment. Analysis of the indirect effect observed in our study illustrate that when the number of people seen
on the lake exceed respondents’ expectations, their perceptions of safety and enjoyment both decline, resulting in lower satisfaction.
These findings have implications for managing recreational boating use on inland lake systems. Given the role played by expectations
in our model, efforts to communicate with boaters about conditions on these waterways is important for helping them plan their
boating experience and avoid situations they consider unsafe or unsatisfactory. 相似文献
446.
Itziar de Aranzabal María F. Schmitz Francisco D. Pineda 《Environmental management》2009,44(5):938-951
Tourism and landscape are interdependent concepts. Nature- and culture-based tourism are now quite well developed activities
and can constitute an excellent way of exploiting the natural resources of certain areas, and should therefore be considered
as key objectives in landscape planning and management in a growing number of countries. All of this calls for careful evaluation
of the effects of tourism on the territory. This article focuses on an integrated spatial method for landscape analysis aimed
at quantifying the relationship between preferences of visitors and landscape features. The spatial expression of the model
relating types of leisure and recreational preferences to the potential capacity of the landscape to meet them involves a
set of maps showing degrees of potential visitor satisfaction. The method constitutes a useful tool for the design of tourism
planning and management strategies, with landscape conservation as a reference. 相似文献
447.
Sorption of alkylphenols on Ebro River sediments: comparing isotherms with field observations in river water and sediments 总被引:1,自引:0,他引:1
Navarro A Endo S Gocht T Barth JA Lacorte S Barceló D Grathwohl P 《Environmental pollution (Barking, Essex : 1987)》2009,157(2):698-703
This study reports sorption isotherms of the endocrine disruptors nonylphenol (NP) and octylphenol (OP) in three sediment samples from the Ebro River basin (NE Spain), with organic carbon fractions (fOC) ranging from 0.0035 to 0.082 gOC g−1. All isotherms were fitted to the Freundlich model with slightly nonlinear exponents ranging from 0.80 to 0.94. The solubility of the compounds as well as the organic carbon (OC) content had the strongest influences on the sorption behavior of these compounds. Comparison of the laboratory-spiked samples with the native contamination of NP of 45 water and concurrent sediment samples resulted in reasonable matches between both data sets, even though the lowest concentrations in the field were not completely reached in laboratory tests. This good agreement indicates that sorption laboratory data can be extrapolated to environmental levels and therefore the distribution of nonylphenol between sediments and water can be predicted with a precision of one order of magnitude. Furthermore, laboratory experiments with simultaneous loading of NP and OP revealed negligible competition for sorption sites at low concentrations. 相似文献
448.
Robert Kase Peter D. Hansen Birgit Fischer Werner Manz Peter Heininger Georg Reifferscheid 《Environmental science and pollution research international》2009,16(1):54-64
Background, aim, and scope The enzyme-linked receptor assay (ELRA) detects estrogenic and anti-estrogenic effects at the molecular level of receptor
binding and is a useful tool for the integrative assessment of ecotoxicological potentials caused by hormonally active agents
(HAA) and endocrine disrupting compounds (EDC). The main advantage of the ELRA is its high sample throughput and its robustness
against cytotoxicity and microbial contamination. After a methodological adaptation to salinity of the ELRA, according to
the first part of this study, which increased its salinity tolerance and sensitivity for 17-β-estradiol, the optimised ELRA
was used to investigate 13 native sediments characterised by different levels of salinity and chemical contamination. The
applicability of the ELRA for routine analysis in environmental assessment was evaluated. Salinity is often a critical factor
for bioassays in ecotoxicological sediment assessment. Therefore, salinity of the samples was additionally adjusted to different
levels to characterise its influence on elution and binding processes of receptor-binding substances.
Materials and methods The ELRA was carried out with the human estrogen receptor α (ER) in a 96-well microplate format using the experimental setup
known from the competitive immunoassay based on ligand–protein interaction. It is an important improvement that a physiologically
relevant receptor was used as a linking protein instead of an antibody. The microplates were coated with a 17-β-estradiol-BSA
conjugate, and dilution series of estradiol and of native sediment samples were added and incubated with the ER. After a washing
step, a biotinylated mouse anti-ER antibody was added to each well. Receptor binding to estradiol, agonistic and antagonistic
receptor binding, were determined by a streptavidin-POD-biotin complex with subsequent measurement of the peroxidase activity
at the wavelength of 450 nm using a commercial ELISA multiplate reader. The sediment elutriates and pore water samples of
sediments were tested in a dilution series to evaluate at which dilution step the receptor-binding potential ends. In the
elution process (see Section 2.1 to 2.2), a method was developed to adjust the salinity to the levels of the reference testings, which offers an appropriate option
to adjust the salinity in both directions. Statistical evaluation was made with a combination of the Mann–Whitney U test and the pT-method.
Results This part of the study characterised the environmental factor ‘salinity’ for prospective applications of the ELRA. Using reference
substances such as 17-β-estradiol, the ELRA showed sigmoid concentration-effect relations over a broad range from 0.05 μg/l
to 100 μg/l under physiological conditions. After methodological optimisation, both sensitivity and tolerance of the assay
against salinity could be significantly raised, and the ELRA became applicable under salinity conditions up to concentrations
of 20.5‰. The mean relative inter-test error (n = 3) was around 11% with reference substances and below 5% for single sediments elutriates in three replicates each. For
sediment testings, the pore water and different salinity-adjusted elutriates of 13 sediments were used. A clear differentiation
of the receptor-binding potential could be reached by application of the pT-method. Thereby, pT-values from one to six could
be assigned to the sediments, and the deviation caused by the different salinity conditions was one pT-value. The mean standard
deviation in the salinity adaptation procedure of the elutriates was below 5%.
Discussion Although the ELRA has already been used for assessments of wastewater, sludge and soil, its applicability for samples to different
salinity levels has not been investigated so far. Even if the ELRA is not as sensitive as the E-screen or the YES-assay, with
regard to reference substances like 17-β-estradiol, it is a very useful tool for pre-screening, because it is able to integrate
both estrogenic as well as anti-estrogenic receptor-binding effects. According to the results of sediment testing, and given
the integrative power to detect different directions of effects, the ELRA shows sufficient sensitivity and salinity tolerance
to discriminate receptor-binding potentials in environmental samples.
Conclusions The optimised ELRA assay is a fast, cost-effective, reliable and highly reproducible tool that can be used for high-throughput
screening in a microplate format in detecting both estrogenic and anti-estrogenic effects. Additionally, the ELRA is robust
against microbial contaminations, and is not susceptible towards cytotoxic interferences like the common cell-culture methods.
The general applicability and sufficient sensitivity of the ELRA was shown in freshwater environments. Marine and brackish
samples can be measured up to salinity levels of 20.5‰.
Recommendations and perspectives In view of the proven sensitivity, functionality and the fastness of the ELRA, it is recommendable to standardise the test
method. At the moment, no adequate in vitro test procedure exists which is standardised to DIN or ISO levels. The E-screen
and the yeast estrogen/androgen screens (YES/YAS) sometimes underlie strong cytotoxic effects, as reported in the first part
of this study. Further development of an ELRA assay using human androgen receptors appears to be very promising to gain information
about androgenic and anti-androgenic effects, too. This would offer a possibility to use the ELRA as a fast and reliable pre-screening
tool for the detection of endocrine potentials, thus minimising time and cost-expensive animal experiments. 相似文献
449.
Mechanistic effect models for ecological risk assessment of chemicals (MEMoRisk)—a new SETAC-Europe Advisory Group 总被引:1,自引:1,他引:0
450.
If no data are available for a specific radionuclide its analogue could be used in radioecological models. They might be used not only in the frame of screening modelling. Relevant processes and features have to be known, such as time scales of these processes, physical, chemical and biological properties of the environment and relevant media. An analogue could only be proven to be valid by comparing its behaviour in the conditions of interest, while confidence in the validity of an analogue will increase as the quality of the justification increases, there will always be some residual uncertainty. Several main types of analogy can be used when measured or recommended values are not available: the same parameter obtained for another isotope of the same element; the same parameter obtained for another element; a different parameter obtained for the same element. There are several cases, when analogues might be applied as indicators of the determining processes in the radioecological studies. 相似文献