盐沼植物对石油污染滩涂微生物群落特性的影响

野外定期采样分析植物生长区根际沉积物和无植物生长区域对应深度的沉积物,研究了海三棱藨草对石油污染滩涂根际沉积物中微生物种群特点、生长条件和脱氢酶活性的影响。结果表明,无论植物是否存在,一般细菌数量均在春季或夏季达到高值。黄杆菌和假单胞菌在春季达到最高值,微球菌和无色杆菌在夏季达到最高值,而在秋季或冬季达到最低值;微球菌...     

Role of pigments on algal communities and photosynthesis

A one-year study of phytoplankton, primary production and related physical and chemical factors was made in a Swiss basin of Lake Lugano (Lago di Lugano). The chlorophylls and 12 carotenoids were analyzed with a TLC technique. The carotenoid monitoring was considered to be particularly interesting, because the role of these pigments in freshwater algae is still very poorly documented by field studies. The dependence of photosynthesis on several factors was statistically evaluated. Evidence was found of light-adaptation phenomena. The variations of photosynthetic activity and efficiency largely depended on the light regime in the few days before the field observations and on the cellular content of chlorophylls and single carotenoids, whose concentrations in their turn were closely linked with light, temperature, average cell size, and with the actual species assemblage.     

Short-term effects of shrub control on two different plant communities in Argentina

The aim of this work was to study the effect of controlling jarilla (Larreaspp.), nonforage shrubs for livestock, on two plant communities with different forage production in the arid mid-west of Argentina. Total vegetation cover, forage species cover and carrying capacity were determined during three growing seasons, for cleared and uncleared plots. At the end of the study, significant differences were found in theLarrea cuneifoliacommunity, where average forage species cover increased by 156% over the control, and greater carrying capacity (129%) was also obtained from the cleared treatment. No significant differences were found in theLarrea divaricatacommunity. Data lead us to recommend shrub control as an improvement practice only in areas with low forage species cover and poor carrying capacity.     

The enigma of social sustainability in rural Australia

While much previous work has been done on the general concept of ecological sustainability, there is relatively little that examines the likely spatial aspects of a socially sustainable rural system. Having defined essential concepts, this study first identifies major current forces for rural change likely to influence any future sustainable system. It goes on to specify those features of modern rural social formations which I believe deserve retention. Finally, some essential requirements for a socially sustainable system are established.     

Disruption of Routine Behaviors Following the Deepwater Horizon Oil Spill

This paper frames the unfolding impacts of the Deepwater Horizon oil spill as a process of lifeway disruption, analyzing the degree to which residents of spill affected communities were prevented from undertaking routine behaviors during the disaster. Special attention is paid to the influence of time, natural resource employment, and community sentiment. Drawing on data from the Louisiana Community Oil Spill Survey, the results show that people in the spill impacted region were prevented from engaging in routine behaviors, though this disruption has steadily decreased over time, suggesting a general trend toward recovery. Consistent with the renewable resource community concept, the results also show that those with ties to the fishing industry were more likely to be prevented from undertaking routine behaviors than were nonfishers. Finally, community sentiment is shown to ameliorate routine behavior disruption, thus, promoting resilience. Overall, these results challenge notions of monolithic paths to disaster recovery.     

沙地柠条(Caragana)灌丛微生境节肢动物群落特征

以宁夏荒漠草原柠条（Caragana）灌丛林地为研究对象,于2011年春、夏、秋季,利用陷阱诱捕法,调查了灌丛微生境节肢动物群落分布特征。结果表明：（1）调查共获得节肢动物9目31科32个类群,分属于4种功能群（植食性、捕食性、腐食性和杂食性）。其中,优势类群为蚁科（Formicidae）和拟步甲科（Tenebrionidae）,个体数占总个体数的71.97%;常见类群有7科8个类群,个体数占总个体数的19.72%;其余22个类群为稀有类群,个体数仅占总个体数的8.30%。（2）随着季节变化,灌丛内外节肢动物类群组成和个体数分布均发生改变。春季灌丛内外均包括优势类群、常见类群和稀有类群;夏季灌丛内外均包括优势类群,而灌丛下仅有常见类群,无稀有类群,灌丛外既没有常见类群也没有稀有类群;秋季灌丛内外均有优势类群和常见类群,但灌丛内外均无稀有类群。（3）夏季灌丛内外共有类群数最少,相似性指数最低,秋季次之,而春季灌丛内外共有类群数最多,相似性指数也最高。（4）春季和秋季,灌丛内外微生境中节肢动物个体数、丰富度和Shannon指数均无显著差异（P>0.05）。夏季,节肢动物个体数灌丛内外无显著差异性（P>0.05）,但丰富度和Shannon指数均表现为灌丛内显著高于灌丛外（P<0.05）。（5）春季灌丛内外捕食性、植食性和杂食性节肢动物的个体数和丰富度均无显著差异性（P>0.05）;但是,腐食性动物个体数和丰富度均表现为灌丛内显著高于灌丛外（P<0.05）。夏季,仅有捕食性动物丰富度呈现出灌丛内显著高于灌丛外（P<0.05）,而其他指标灌丛内外均无显著差异性（P>0.05）。秋季,每种功能群动物的个体数和丰富度灌丛内外均无显著差异性（P>0.05）。沙地灌丛内外生境中节肢动物的空间分布,既与灌丛本身生理生态学特性相关,也与季节性降雨和温度等气象条件的改变密切相关。     

Fisheries privatization,social transitions,and well-being in Kodiak,Alaska

Scholars and fishermen alike view the privatization of fishing rights as a fundamental driver of social change in fishing communities. This article presents the results of a mixed-methods ethnographic study in Kodiak, Alaska, exploring how fisheries privatization processes remake fishery systems. Findings from this study suggest that a diverse range of fishery participants share core values about the social dimensions of fishery systems. Support or opposition to past privatization processes tended to be articulated in reference to how these core values (e.g., hard work, opportunity, and fairness) were perceived to have been strengthened or eroded by such processes. Data from this study suggest that while still widespread in the Kodiak fishing community, core social values in fishing may be changing as a result of privatization processes. Although ethnographic and survey data showed a range of perspectives on the effects of privatization on fishing and the Kodiak community, study participants tended to talk about privatization as a significant change that had divisive, negative impacts in the community. Crew members and the next generation of fishermen were identified as disproportionately affected by privatization processes. Ethnographic data detail important shifts in the power, status, and livelihoods of crew members. Nearly all Kodiak fishery participants interviewed expressed concern about the future of fisheries access in the community for the next generation, in large part because of the substantial financial barriers to entry generated by privatization of fisheries access. Many discussed the need for more entry-level opportunities necessary for access in all fisheries.     

Cities On the Plains: The Evolution of Urban Kansas

The process of congressional redistricting, delineating boundaries for districts in which voters elect members to the U.S. House of Representatives, has always been an expensive and controversial process. Congressional districts (CDs) are redrawn due to changes in population reflected by the decennial census to ensure equal representation. Laws and regulations literature identifies eight criteria that may be considered when determining the boundaries of CDs and this article focuses on one of those criteria, maintaining communities of interest (COIs). This criterion requires states to preserve these boundaries when delineating CDs but fails to define a COI. This research proposes and evaluates two approaches to define a COI and examines the extent to which this criterion has been adhered to. One definition uses Thiessen polygons and census designated places to delineate COIs based on known cultural places, whereas the other definition uses cluster analysis to group together people with similar sociodemographic characteristics. The results show that the two definitions are feasible for defining a COI. Furthermore, the states largely maintain the COI boundaries within their CDs by only splitting, at most, 17.1 percent of the COIs defined. Existing literature shows that maintaining COIs within CDs leads to higher voter participation and engagement, as well as better representation. The results show that if either definition was adopted, states could comply with this criterion with relative ease. Furthermore, a standard definition could help reduce the cost and controversy surrounding the redistricting process.     

Gender,Work, and Household Survival in South Indian Fishing Communities: A Preliminary Analysis

This article examines the interplay of gender, caste-religion, and household survival strategy formation among Christian and Muslim fisher folk in the south Indian state of Kerala. The methodology consisted of surveys of forty-one households in two villages in which data pertaining to male and female work patterns and other household level data were collected in the summer of 1999. My analysis demonstrates how particular ideologies of gender and work associated with different caste-religion communities influence the strategies individual households adopt. I discuss intersections between gender and caste-religion with other socioeconomic factors and illustrate the manner in which gender then gets reworked in particular ways in the course of economic transformation.