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41.
Kendall J. Bryant 《Journal of environmental psychology》1984,4(1):43-60
Two perspectives in the analysis of pointing and mapping tasks as the measure of representations of the large-scale environment are examined. These two perspectives are: (1) an individual difference approach; and (2) a cognitive representational approach. Convergence between methods assessing the same geographical/spatial knowledge is necessary as evidence for the existence of unified cognitive-spatial representations of the environment.Three sets of analyses interrelate performance on pointing and mapping tasks. In the first analysis, a confirmatory factor analytic model is applied to short tests of pointing and mapping accuracy to determine whether one or two factors are needed to account for covariation between the tests. In the second analysis, covariation among errors in pointing and mapping of specific locations is partitioned into general and specific method factors using the Schmid-Leiman procedure. In the third analysis, pointing errors for identical locations within the mapping and pointing tasks are directly compared on the basis of directional errors.The three analyses indicate that: (1) tests of pointing and mapping measure highly related abilities; (2) the targets used in pointing and mapping tasks are of differential importance in identifying general and specific method factors; and (3) there is little or no direct correspondence between directional errors made in pointing tasks and those occurring in mapping tasks for the same locations.When results of the three analyses are examined in relationship to criteria for convergence of pointing and mapping tasks, little evidence is found to suggest that directional errors in these tasks arise from a unified mental representation of the geographical environment. However, substantial predictable individual differences are apparent for both tasks. 相似文献
42.
Dominika Saniewsk Magdalena Beldowsk Jacek Beldowski Micha? Saniewski Justyna Kwa′sniak Lucyna Falkowska 《环境科学学报(英文版)》2010,22(8):1144-1150
The aim of this study was to characterize mercury (Hg) contamination in the coastal waters of the Southern Baltic Sea, and to
investigate transformations of Hg in the initial links of the marine food chain. Concentrations of Hg in water, particulate matter,
plankton and macrophytes at various stations in the coastal zone (a bay with restricted water exchange, near an industrial city, river
mouths, and the open sea) were measured in 2006–2008. Hg concentrations observed in the Southern Baltic varied greatly, showing
the highest average values in all environmental compartments near the river mouths. In shallow, sheltered parts of the gulf, where water
exchange is restricted, Hg concentrations in the water and in macrophytes were elevated relative to those in the coastal zone of the
deeper part of the bay and in the open Baltic. Distance to the river mouth, terrestrial runo , and quantity and quality of organic matter
were more important than seasonal variations in controlling Hg and HgSPM concentrations in water samples. Mercury concentrations in
the surface microlayer at the air/sea interface were over 10 times higher than those in the bulk surface water. Concentrations of Hg in
macrophytes in the winter were significantly higher than those in the warm seasons (spring, summer, autumn). This was probably the
combined e ect of higher availability of Hg in porewaters and leaf growth inhibition. 相似文献
43.
Disc size regulation in the brood cell building behavior of leaf-cutter bee, <Emphasis Type="Italic">Megachile tsurugensis</Emphasis> 总被引:2,自引:1,他引:1
Kim JY 《Die Naturwissenschaften》2007,94(12):981-990
The leaf-cutter bee, Megachile tsurugensis, builds a brood cell in a preexisting tunnel with leaf discs that she cuts in decreasing sizes and assembles them like a
Russian matryoshka doll. By experimentally manipulating the brood cell, it was investigated how she regulates the size of
leaf discs that fit in the brood cell’s internal volume. When the internal volume was artificially increased by removing a
bulk of leaf discs, she decreased the leaf disc size, although increasing it would have made the leaf disc more fitting in
the increased internal volume. As a reverse manipulation, when the internal volume was decreased by inserting a group of inner
layers of preassembled leaf discs to a brood cell, she decreased the leaf disc size, so that the leaf disc could fit in the
decreased internal volume. These results suggest that she uses at least two different mechanisms to regulate the disc size:
the use of some internal memory about the degree of building work accomplished in the first and of sensory feedback of dimensional
information at the construction site in the second manipulation, respectively. It was concluded that a stigmergic mechanism,
an immediate sensory feedback from the brood cell changed by the building work, alone cannot explain the details of the bee’s
behavior particularly with respect to her initial response to the first manipulation. For a more complete explanation of the
behavior exhibited by the solitary bee, two additional behavioral elements, reinforcement of building activity and processing
of dimensional information, were discussed along with stigmergy. 相似文献
44.
This work describes how a general, process-based mass-balance model (CoastMab) for phosphorus for coastal areas may be used as a tool to estimate realistic values of “natural” or preindustrial reference levels of key bioindicators in coastal science, including the Secchi depth, a standard measure of water clarity, the chlorophyll-a concentration, an operational measure of phytoplankton biomass and the concentration of cyanobacteria, a measure of the concentration of harmful algae. The CoastMab-model is an ecosystem model giving monthly predictions to achieve seasonal variations of basin-wide properties. The selected case-study area, the Gulf of Riga, is sensitive to nutrient loading because of its shallowness and low openness towards the Baltic Proper. The morphometry of any coastal area, as given by the size and form parameters, influences all internal processes, such as sedimentation, resuspension, diffusion in water and from sediments to water, biouptake and retention in biota, stratification, mixing and outflow. There has been no mass-balance modeling for nitrogen (N) in this work because empirical data (from the HELCOM database) clearly indicate that the monthly primary production in the Gulf of Riga is regulated by phosphorus (P) – the mean monthly total-N to total-P ratios are well over 7.2 (the Redfield-ratio) and generally higher than 15 for the data used in this study (from 1992 to 2005). At present anthropogenic loads, the average modeled monthly values for Secchi depth, chlorophyll (Chl), cyanobacteria (CB) and total-P (TP) are 3.2 m, 3.8 μg/l, 78 μg/l and 31.3 μg/l, respectively. If 50% of all anthropogenic sources to the Gulf of Riga via rivers, point sources and diffuse sources were to be removed, these values would be 3.6 m, 3.4 μg Chl/l, 63 μg CB/l and 29.1 μg TP/l. If 60% of the anthropogenic phosphorus fluxes to the Baltic Proper were to be omitted and as well as 75% of all direct anthropogenic sources to the Gulf of Riga, the values would be 4.6 m, 2.7 μg Chl/l, 45 μg CB/l and 25.4 μg TP/l. These values represent the “natural” reference levels and it is not realistic to expect that remedial measures would improve the conditions more than that. Using the CoastWeb-model, similar calculations can be made for any given coastal area and the data necessary for such calculations are discussed in this work. 相似文献
45.
The Costs of Meeting the Environmental Objectives for the Baltic Sea: A Review of the Literature 总被引:1,自引:0,他引:1
Katarina Elofsson 《Ambio》2010,39(1):49-58
The environmental targets of the recently agreed Baltic Sea Action Plan (BSAP) targets are likely associated with a considerable
cost, which motivates a search for low-cost policies. The following review shows there is a substantial literature on cost-efficient
nutrient reduction strategies, including suggestions regarding low-cost abatement, but actual policies at international and
national scale tend to be considerably more expensive due to lack of instruments that ensure a cost-efficient allocation of
abatement across countries and sectors. Economic research on the costs of reducing hazardous substances and oil spill damages
in the Baltic Sea is not available, but lessons from the international literature suggest that resources could be used more
efficiently if appropriate analysis is undertaken. Common to these pollution problems is the need to ensure that all countries
in the region are provided with positive incentives to implement international agreements. 相似文献
46.
Leachates of anti-fouling paints for use on ships and leisure boats are examined for their ecotoxicological potential. Paint leachates were produced in both 7‰ artificial (ASW) and natural seawater (NSW) and tested on three organisms, the bacterium Vibrio fischeri, the macroalga Ceramium tenuicorne, and the crustacean Nitocra spinipes. Generally, leaching in ASW produced a more toxic leachate and was up to 12 times more toxic to the organisms than was the corresponding NSW leachate. The toxicity could be explained by elevated concentrations of Cu and Zn in the ASW leachates. Of the NSW leachates, those from the ship paints were more toxic than those from leisure boat paints. The most toxic paint was the biocide-free leisure boat paint Micron Eco. This implies that substances other than added active agents (biocides) were responsible for the observed toxicity, which would not have been discovered without the use of biological tests. 相似文献
47.
Models that can project ecosystem dynamics under changing environmental conditions are in high demand. The application of such models, however, requires model validation together with analyses of model uncertainties, which are both often overlooked. We carried out a simplified model uncertainty and sensitivity analysis on an Ecopath with Ecosim food-web model of the Baltic Proper (BaltProWeb) and found the model sensitive to both variations in the input data of pre-identified key groups and environmental forcing. Model uncertainties grew particularly high in future climate change scenarios. For example, cod fishery recommendations that resulted in viable stocks in the original model failed after data uncertainties were introduced. In addition, addressing the trophic control dynamics produced by the food-web model proved as a useful tool for both model validation, and for studying the food-web function. These results indicate that presenting model uncertainties is necessary to alleviate ecological surprises in marine ecosystem management. 相似文献
48.
Pekcan-Hekim Z Urho L Auvinen H Heikinheimo O Lappalainen J Raitaniemi J Söderkultalahti P 《Ambio》2011,40(5):447-456
Climate change scenarios concerning the Baltic Sea predict increase in surface water temperatures. Pikeperch (Sander lucioperca (L.)) inhabits the coastal areas of the northern Baltic Sea and is an important fish species for the Finnish fisheries. The
year-class strength of pikeperch varies strongly between years and significantly depends on water temperature. We aimed to
study the effects of changing temperature conditions on pikeperch fisheries and distribution based on commercial catch data
from the period 1980–2008 in the Finnish coastal areas of the Baltic Sea. The results indicated that warmer summers will produce
stronger pikeperch year-classes that consequently contribute significantly to the future catches. The average temperature
in June–July explained 40% of the variation in the year-class catches in the Gulf of Finland and 73% in July–August in the
Archipelago Sea. During the study period, the distribution of pikeperch catches expanded toward north along the coasts of
the Bothnian Sea. 相似文献
49.
Successful implementation of an international nutrient abatement agreement, such as the Baltic Sea Action Plan (BSAP), requires
consistent understanding of the baseline nutrient loads, and a perception of acceptable costs and fairness in targeted reductions
of these base line loads. This article presents a general framework for identifying the implications of divergence between
different nutrient load quantification approaches, with regard to both cost and fairness criteria outcomes, for the international
agreement to decrease nutrient loads into the Baltic Sea as presented in the BSAP. The results indicate that even relatively
small divergence in the nutrient load quantification translates into relatively large differences in abatement cost for different
Baltic Sea countries. A robust result, irrespective of differences in nutrient load assessments, is a conflict between abatement
cost effectiveness and fairness, with relatively poor countries facing heavy abatement cost burdens for cost-effective international
load abatement. 相似文献
50.