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1.
Although it is commonly recognized that parenting is multiply determined, mechanisms by which the context influences parental behavior have rarely been examined. In this paper, the role of environmental affordances and demands are described and tested in two observational studies. In Study 1, mothers and their 3-year-old children were observed in three settings where affordances and demands differed: the home, park, and laboratory. In Study 2, mothers and their children engaged in three laboratory conditions in which the amount of demands on the mother was manipulated. Several child-rearing variables showed systematic relations with the presence of affordances and demands. It is concluded that affordances and demands play an important role in influencing maternal behavior by acting as environmental cues for place-related behavior. Further, it is proposed that parental perceptions of the immediate context and the recognition of appropriate environmental cues are paramount in understanding the variability of parental behavior across situational contexts.  相似文献   

2.
ABSTRACT: The Central Nebraska Basins is one of 60 study units in the National Water-Quality Assessment Program of the U.S. Geological Survey. The study unit includes the Platte River and two major tributaries, the Loup and Elkhorn Rivers. Agriculture is the predominant land use in the study unit, with only eight urbanized communities exceeding a population of 10,000. Water samples were collected from selected streams in the study unit during 1993–1995. The data were used to assess the distribution of nitrogen compounds and phosphorus in the streams and to relate the concentrations of these constituents to environmental settings. This article focuses on dissolved nitrate and orthophosphate. Dissolved nitrate concentrations were highest (90th percentiles were less than 7.0 milligrams per liter as nitrogen) in areas with extensive cropland and pasture, where chemical fertilizers are intensively applied. Synoptic measurements conducted in March and August 1994 indicate that relatively little residual fertilizer, as nitrate, applied during a single crop-growing season enters streams. Dissolved nitrate concentrations showed a seasonal pattern, being highest during winter months and lowest during the late spring and summer. Dissolved orthophosphate concentrations tended to be low across the study unit, 90 percent of all analyses did not exceed 1.7 milligrams per liter as phosphorus.  相似文献   

3.
This paper critically reflects on the challenges of engaging, proactively, in Corporate Social Responsibility (CSR) in oil-rich sub-Saharan Africa. Most of the region's oil production takes place in enclave-type environments offshore and in countries ruled by autocratic governments which generally exert minimal pressure on companies to embrace CSR. With companies having little sense of who to target in their local economic development policies and programs, there is always a possibility of ‘offshore CSR’ – recognized here as potentially-effective ideas for improving social welfare that linger within the enclave and never fully materialize – surfacing. The aim is to conceptualize and broaden understanding of the challenge of developing CSR programs in these settings, where there are no clear linkages to communities or local economies more generally.  相似文献   

4.
An understanding of temporal trends in total stream‐flow (TSF), base flow (BF), and storm runoff (RO) can help in the development of water management plans for watersheds and local communities. In this study, 47 streams across Pennsylvania that were unregulated and unaffected by karst environments or coal mining were studied for flow trends and their relationships to selected climate parameters for the period 1971 to 2001. LOWESS curves for annual flow showed that almost all of the selected streams in Pennsylvania had downward trends in total TSF, BF, and RO. Using a seasonal Mann‐Kendall analysis, downward trends were significant at an α= 0.05 level for 68, percent 70 percent, and 62 percent of the streams and at an α= 0.10 level for another 19, 17, and 13 percent of the streams for TSF, BF, and RO, respectively. The ratio of BF to TSF (RBS) had significant upward trends for 34 percent of the streams at an α= 0.05 level and for another 9 percent of the streams at an α= 0.10 level, indicating that TSF decreased relative to BF for more than 40 percent of the streams during the previous 30 years. Downward trends in TSF, BF, and RO were most common for the months of June, July, and December. Trend analyses using monthly and annual total precipitation and mean temperature showed some association between climate and the streamflow trends, but Spearman's correlation and partial Mann‐Kendall analyses revealed that the trends in TSF, BF, and RO could not be explained by trends in precipitation and temperature alone, and thus urbanization and development may have played a role.  相似文献   

5.
ABSTRACT: Macroinvertebrate community data collected from streams in Wyoming were assessed at various scales: within one stream reach, between stream reaches within one stream, between streams, and between stream classes. Fourteen indices including number of individuals/m2, biomass/m2, number of taxa, Shannon's diversity index, and functional feeding group ratios were used to compare macroinvertebrates by stream reach and stream class. Statistical analysis indicated that for five of the 14 indices, significant variability occurred between macroinvertebrate communities within one reach. For two of the remaining nine indices there was significant variability between communities from several reaches within the same stream. For seven of the nine indices, there was significant variability among macroinvertebrate communities from streams of the same class. Variability among the macroinvertebrate communities from the three stream classes was significantly different for seven of the nine indices. ANOVA results suggest that macroinvertebrate communities from different samples within one reach and between reaches within one stream were more comparable than those from different streams and different stream classes.  相似文献   

6.
The two studies reported further test reversal theory hypotheses concerning human psychological responses to different types of settings and environmental events on an Asian sample. In study 1, individuals in four settings representing different combinations of metamotivational state and arousal level (telic and paratelic/low arousal; telic and paratelic/high arousal) completed the telic state measure (TSM; Svebak & Murgatroyd, 1985). Significant differences between participants' mean scores across the four settings were obtained for TSM items serious–playful, planning–spontaneous, felt arousal, preferred arousal, effort and arousal discrepancy. In study 2 different environmental events in the same setting (changes in reading tasks), used in a crossover design, were used to induce reversals in individuals' operative metamotivational states. The results obtained from TSM scores pretask 1, between tasks and posttask 2. indicated significant time-of-testing interaction effects on the TSM serious–playful, planning–spontaneous and effort items. In addition, a main effect for TSM felt arousal was found. These results showed that reversals in metamotivational states were induced by the environmental event and that felt arousal scores increased across the three administrations of the TSM.  相似文献   

7.
ABSTRACT: Accurate estimates of evapotranspiration from areas dominated by wetland vegetation are needed in the water budget of the Upper St. Johns River Basin. However, local data on evapotranspiration rates, especially in wetland environments, were lacking in the project area. In response to this need, the St. Johns River Water Management District collected evapotranspiration field data in Fort Drum Marsh Conservation Area over the period 1996 through 1999. Three large lysimeters were installed to measure the evapotranspiration from different wetland environments: sawgrass (Cladium jamaicense), cattail (Typha domingensis), and open water. In addition, pan evaporation was measured with a standard class “A” pan. Concurrently, meteorological data including rainfall, solar radiation, wind speed, relative humidity, air temperature, and atmospheric pressure were collected. By comparing computed evapotranspiration rates with those measured in the lysimeters, parameters in the Penman‐Monteith, the Priestley‐Taylor, and Reference‐ET methods, and evaporation pan coefficients were estimated for monthly and seasonal cycles. The results from the data collected in this study show that mean monthly evapotranspiration rates, computed by the different methods, are relatively close. From a practical point of view, results indicate that the evaporation pan can be used equally well as the more complex and data‐intensive methods. This paper presents the measured evapotranspiration rates, evaporation pan coefficients, and the estimated parameter values for three different methods to compute evapotranspiration in the project area. Since local data on evaporation are often scarce or lacking, this information may be useful to watershed hydrologists for practical application in other project regions.  相似文献   

8.
The psychological effects of unusual environments reveal different aspects of behaviour from those seen in more customary situations. Such environments provide natural laboratories in which many questions of psychological interest, varying with the specific environment, may be studied. This paper uses isolated polar stations to illustrate this point. In such settings, the usual parameters that control a variety of psychological processes are drastically changed, and confounding variables are stripped away. Consequently, the environment offers unique perspectives on environmental perception and cognition; adaptation to and use of the environment; environmental bonding; social interaction; and coping with environmental challenge.  相似文献   

9.
ABSTRACT: Spatial distributions of nitrogen and phosphorus in water were related to environmental setting as part of a regional water-quality assessment of the Central Nebraska Basins. The environmental settings (Sandhills, Loess Hills, Glaciated Area, and Platte Valley) were characterized by different concentrations of nitrogen and phosphorus in ground water and stream water. Statistically significant differences in nitrate concentrations in both ground-water and stream-water samples were related to regional distributions of cropland and rangeland. Nitrate concentrations were larger, especially in shallow ground water, in environmental settings dominated by cropland and associated fertilizer use than in settings dominated by rangeland. Similarly, total-nitrogen and nitrate concentrations were relatively large in selected streams draining primarily cropland. Comparative concentrations of phosphorus in stream water on the basis of environmental setting were similar to those of nitrogen, although the largest phosphorus concentrations probably relate to wastewater discharge into small streams. Nitrogen and phosphorus concentrations in much of the Platte River apparently reflected the quality of water entering the study unit from upstream and limited base-flow contributions from within the Platte Valley itself.  相似文献   

10.
In many countries, an increasing amount of attention is being paid to the economic and environmental repercussions of mineral resources development, and in particular to the problems of industrialisation of an agricultural society. In Botswana, the discovery of and planning for the development of nickel deposits is an important element of national policy. However, often overlooked is the basic and continuing role that has to be provided by the agricultural sector. The pressure of people and of livestock on the land, and the extension of cultivation into increasingly fragile environments where the availability of water is a critical constraint, pose serious problems for policy makers. The author examines the dilemma in a case study of Botswana, showing how changes in the agricultural sector have precipitated problems of water supply and of environmental stress. The need for inter-disciplinary approaches to policy making is underscored, together with detailed and integrated studies of the dimensions of these inter-related problems. The problem of the availability of water in adequate quantities and of appropriate quality has become a serious policy concern. Later this year the United Nations Conference on Desertification will address the broad scope of the relationships between man, land and water. This article examines one example of these changing relationships.  相似文献   

11.
ABSTRACT: This study was conducted in the Klamath Basin of southwestern Oregon to evaluate the dependency of riparian plant communities upon infrequent flooding. Plant communities were sampled with 1 m2 quadrats along established cross‐sections. Data collected for purposes of hydraulic modeling included channel and floodplain elevations (i.e., cross‐sectional profiles) and water surface elevations associated with specific discharges. The elevational distribution of hydrophytic plant communities relative to modeled return periods provided the basis for establishing relationships between these variables for nine sites. Results indicate that, on average, a peak flow frequency of 4.6 years (range of 3.1 to 7.6 years) was needed to sustain riparian plant communities at seven of nine sites. At two sites, results indicated return periods of more than 25 years were needed; these results possibly were influenced by local geomorphic conditions (a narrow steep channel in one case and an incised channel in the other). Overall, these results tend to confirm a strong dependency of riparian plant communities on overbank flows.  相似文献   

12.
The European Landscape Convention (2000) obligates European Union countries to identify and implement landscape quality objectives (LQOs) understood as the specification of public expectations and preferences concerning the landscape of a given area, expressed by competent public authorities. The convention emphasizes the important role of local community representatives in this field. In Poland, the implementation of the LQO concept was first undertaken in two regions with radically different landscape characteristics: (1) the West Polesie Biosphere Reserve and (2) the selected protected areas of the Roztocze–Solska Forest, nominated to the rank of a biosphere reserve. The first stage of the presented study was the recognition of public opinion on the quality of key features of landscape, based on a questionnaire (n = 470). The primary objective of the study was to provide an answer to the following questions: (1) Whether similar social expectations regarding landscape quality exist in spite of radically different landscape characteristics of the regions investigated (landscape quality is understood as spatial arrangement, scenic beauty, and lack of environmental pollution); (2) which landscape features are considered to be most preservation worthy by the representatives of both local communities; and (3) What processes or development impacts pose the greatest threat to the landscape quality of both regions according to the public opinion? The conducted comparative assessment revealed that it is possible to define a set of features fundamental to the quality of both areas and that representatives of local communities pointed out the same threats to the natural and cultural values of both regions investigated.  相似文献   

13.
Previous research notes that sense of place may intensify, and that levels of public risk perception may decrease with proximity to an established hazardous or stigmatised site. In addition, the literature suggests that sense of place may act either to mediate or moderate community perceptions of risk in such localities. This study comprised a major household survey (n = 1326) and an interview study (n = 39) and was conducted close to the nuclear power stations at Oldbury and Hinkley Point, both in the UK. It investigated the roles of perceptions of place and hazard proximity in considering (a) perceptions of risk and (b) public attitudes towards the building of a new nuclear power station in the nearby area. In addition, a novel scale was developed to measure the perceived contribution of the nearby nuclear power station to sense of place. The results suggest first, that sense of place mediates (but does not moderate) perceptions of risk in very proximate communities, and second, that public attitudes to new build in communities situated very close to established nuclear sites may be largely dependent on the extent to which the existing facility is perceived to contribute towards sense of place. The implications of these results for existing theory are discussed.  相似文献   

14.
In the coastal temperate rainforest of British Columbia (BC) in western Canada, government policies stipulate that foresters leave unlogged hydroriparian buffer strips up to 25 m on each side of streams to protect wildlife habitat. At present, studies on the effectiveness of these buffers focus on mammals, birds, and amphibians while there is comparably little information on smaller organisms such as liverworts in these hydroriparian buffers. To address this gap of knowledge, we conducted field surveys of liverworts comparing the percent cover and community composition in hydroriparian forested areas (n = 4 sites, n = 32 plots with nested design) to hydroriparian buffer zones (n = 4 sites, n = 32 plots). We also examined how substrate type affected the cover of liverworts. Liverwort communities in buffers were similar to those in riparian forest areas and most liverworts were found on downed wood. Thus, hydroriparian buffers of 25–35 m on each side in a coastal temperate rainforest effectively provide habitat for liverworts as long as downed wood is left intact in the landscape. Because liverworts are particularly sensitive to changes in humidity, these results may indicate that hydroriparian buffers are an effective management strategy for bryophytes and possibly for a range of other riparian species that are particularly sensitive to forestry-related changes in microclimate.  相似文献   

15.
ABSTRACT: Brillouin's equation (H) for species diversity from information theory is to be preferred for the purposes of applied ecology over the equation of Shannon (H′) or the more commonly used approximate equation (H″). By its use, the difficult problem of delimiting the extent of the community being sampled in a stream survey can be avoided. Moreover, Brillouin's equation gives the exact diversity of the fully censused collection, whreas Shannon's diversity can only be approximated with a biased estimator. If we regard a sample as a message from the environment to the ecologist, Brillouin's equation is the proper one for computing its diversity. The product moment correlation coefficient between Brillouin's H for the total number of individuals from a group of samples and for randomly chosen subsets of 100 individuals from each sample was nearly as high as the correlation between H and H″ based on the total samples. This indicates that small sample sizes may give a useful diversity index. Replicated subsamples show that much smaller samples than are normally used can discriminate between communities from polluted and unpolluted environments. The use of smaller samples should reduce the cost of stream surveys.  相似文献   

16.
ABSTRACT: We measured the base‐flow stream chemistry in all the major physiographic provinces of the Chesapeake Bay drainage basin. The spatial variation of stream chemistry was closely related to differences in geology and land cover among the sampled watersheds. Some stream chemistry variables were strongly affected by geological settings in the watersheds while others were more influenced by land cover. The effects of land cover differed among chemical constituents and regions. Concentrations of Ca2+, Mg2+, pH, total alkalinity, and conductivity were mainly functions of carbonate bedrock, especially in the Great Valley. Nitrate‐N and total dissolved N were closely related to cropland and increased as the percentage of cropland increased. The rate of increase varied from region to region with the highest in the Piedmont. Na+ and Cl? were mainly affected by the percentage of developed area in a watershed, especially in the Coastal Plain and Piedmont. We observed no significant effects of region or land cover on species of phosphorus because samples were collected under base flow conditions and only dissolved forms were measured. Dissolved silicate (DSi) was not related to any other water chemistry variables. DSi increased as developed area decreased and cropland increased in the Coastal Plain, but these patterns were reversed in the Piedmont. There was no consistent pattern in the spatial variation of land cover effects on the reduced forms of N, dissolved organic P, dissolved organic matter, and K+.  相似文献   

17.
ABSTRACT: We evaluated the effectiveness of watershed‐scale implementations of best‐management practices (BMPs) for improving habitat and fish attributes in two coldwater stream systems in Wisconsin. We sampled physical habitat, water temperature, and fish communities in multiple paired treatment and reference streams before and after upland (barnyard runoff controls, manure storage, contour plowing, reduced tillage) and riparian (stream bank fencing, sloping, limited rip‐rapping) BMP installation in the treatment subwatersheds. In Spring Creek, BMPs significantly improved overall stream habitat quality, bank stability, instream cover for fish, abundance of cool‐ and coldwater fishes, and abundance of all fishes. Improvements were most pronounced at sites with riparian BMPs. Water temperatures were consistently cold enough to support coldwater fishes such as trout (Salmonidae) and sculpins (Cottidae) even before BMP installation. We observed the first‐time occurrence of naturally reproduced brown trout (Salmo trutta) in Spring Creek, indicating that the stream condition had been improved to be able to partially sustain a trout population. In Eagle Creek and its tributary Joos Creek, limited riparian BMPs led to localized gains in overall habitat quality, bank stability, and water depth. However, because few upland BMPs were installed in the subwatershed there were no improvements in water temperature or the quality of the fish community. Temperatures remained marginal for coldwater fish throughout the study. Our results demonstrate that riparian BMPs can improve habitat conditions in Wisconsin streams, but cannot restore coldwater fish communities if there is insufficient upland BMP implementation. Our approach of studying multiple paired treatment and reference streams before and after BMP implementation proved effective in detecting the response of stream ecosystems to watershed management activities.  相似文献   

18.
19.
Many authors have suggested that Indigenous communities are especially vulnerable to the direct and indirect impacts of climate change, yet there remains a paucity of fine-grained geographic data on the particular impacts of climate change on specific places and on local communities, especially Australian Indigenous communities. While there are some recent studies being undertaken with Australia's Torres Strait Island people, our research takes up the issues of vulnerability and resilience with two Indigenous communities from different environments on the mainland in North Queensland. They are the Aboriginal peoples of the rainforest and reef environments of the Wet Tropics and the Aboriginal people of the discontiguous rainforest, grasslands, dry forests and marine environments of Cape York. The results demonstrate variability in their understandings of climate change and in their capacities to anticipate and manage its impacts, while at the same time illustrating some common held themes about environmental and cultural values, observed environmental change, attributions of cause and effect, and of climate in general.  相似文献   

20.
MEANING AND FORM IN COMMUNITY PERCEPTION OF TOWN CHARACTER   总被引:1,自引:0,他引:1  
This study explored the notion of ‘town character’ within the context of one Australian coastal town from the perspective of the community. Responses from a sample of residents to a set of local environmental features were collected using adjective rating scales. Data concerning the perceived character compatibility of features was also collected. Several multivariate statistical procedures, including multi-dimensional scaling, were used to explore the underlying structure in the response pattern and to determine the salience of meanings related to the community's conception of town character, as conveyed through local landscape features. Town character in the context of this study was found to be related to a variety of environmental features and associated meanings. Specifically, a positive character image was strongly supported by natural landscape features associated with their naturalness, beauty, pleasantness, distinctiveness, and interest, by certain built features, (specifically landmark features), associated with their distinctiveness, pleasantness, charm, familiarity, and interest, and by popular social settings associated with connotations of familiarity, friendliness, openness, liveliness, and safety. Features identified as incompatible with local character were associated with negative meanings that included boredom, ugliness, lack of charm, lack of stimulation, monotony, unpleasantness, and being ordinary.  相似文献   

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