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Native Communities (native + community)
Selected AbstractsCultural and spiritual coping in sobriety: Informing substance abuse prevention for Alaska Native communitiesJOURNAL OF COMMUNITY PSYCHOLOGY, Issue 5 2001Kelly L. Hazel Culture and spirituality have been conceptualized as both protecting people from addiction and assisting in the recovery process. A collaborative study, utilizing focus group and survey methods, defined and examined cultural and spiritual coping in sobriety among a select sample of Alaska Natives. Results suggest that the Alaska Native worldview incorporates a circular synthesis and balance of physical, cognitive, emotional, and spiritual processes within a protective layer of family and communal/cultural beliefs and practices embedded within the larger environment. Cultural-spiritual coping in sobriety is a process of appraisal, change, and connection that leads the person toward achieving an overarching construct: a sense of coherence. Cultural and spiritual processes provide important areas for understanding the sobriety process as well as keys to the prevention of alcohol abuse and addiction. © 2001 John Wiley & Sons, Inc. [source] Elevated dominance of extrafloral nectary-bearing plants is associated with increased abundances of an invasive ant and reduced native ant richnessDIVERSITY AND DISTRIBUTIONS, Issue 5 2009Amy M. Savage Abstract Aim, Invasive ants can have substantial and detrimental effects on co-occurring community members, especially other ants. However, the ecological factors that promote both their population growth and their negative influences remain elusive. Opportunistic associations between invasive ants and extrafloral nectary (EFN)-bearing plants are common and may fuel population expansion and subsequent impacts of invasive ants on native communities. We examined three predictions of this hypothesis, compared ant assemblages between invaded and uninvaded sites and assessed the extent of this species in Samoa. Location, The Samoan Archipelago (six islands and 35 sites). Methods, We surveyed abundances of the invasive ant Anoplolepis gracilipes, other ant species and EFN-bearing plants. Results,Anoplolepis gracilipes was significantly more widely distributed in 2006 than in 1962, suggesting that the invasion of A. gracilipes in Samoa has progressed. Furthermore, (non- A. gracilipes) ant assemblages differed significantly between invaded and uninvaded sites. Anoplolepis gracilipes workers were found more frequently at nectaries than other plant parts, suggesting that nectar resources were important to this species. There was a strong, positive relationship between the dominance of EFN-bearing plants in the community and A. gracilipes abundance on plants, a relationship that co-occurring ants did not display. High abundances of A. gracilipes at sites dominated by EFN-bearing plants were associated with low species richness of native plant-visiting ant species. Anoplolepis gracilipes did not display any significant relationships with the diversity of other non-native ants. Main conclusions, Together, these data suggest that EFN-bearing plants may promote negative impacts of A. gracilipes on co-occurring ants across broad spatial scales. This study underscores the potential importance of positive interactions in the dynamics of species invasions. Furthermore, they suggest that conservation managers may benefit from explicit considerations of potential positive interactions in predicting the identities of problematic invaders or the outcomes of species invasions. [source] Prediction and validation of the potential global distribution of a problematic alien invasive species , the American bullfrogDIVERSITY AND DISTRIBUTIONS, Issue 4 2007Gentile Francesco Ficetola ABSTRACT Predicting the probability of successful establishment and invasion of alien species at global scale, by matching climatic and land use data, is a priority for the risk assessment. Both large- and local-scale factors contribute to the outcome of invasions, and should be integrated to improve the predictions. At global scale, we used climatic and land use layers to evaluate the habitat suitability for the American bullfrog Rana catesbeiana, a major invasive species that is among the causes of amphibian decline. Environmental models were built by using Maxent, a machine learning method. Then, we integrated global data with information on richness of native communities and hunting pressure collected at the local scale. Global-scale data allowed us to delineate the areas with the highest suitability for this species. Predicted suitability was significantly related to the invasiveness observed for bullfrog populations historically introduced in Europe, but did not explain a large portion of variability in invasion success. The integration of data at the global and local scales greatly improved the performance of models, and explained > 57% of the variance in introduction success: bullfrogs were more invasive in areas with high suitability and low hunting pressure over frogs. Our study identified the climatic factors entailing the risk of invasion by bullfrogs, and stresses the importance of the integration of biotic and abiotic data collected at different spatial scales, to evaluate the areas where monitoring and management efforts need to be focused. [source] The predatory impact of the freshwater invader Dikerogammarus villosus on native Gammarus pulex (Crustacea: Amphipoda); influences of differential microdistribution and food resourcesJOURNAL OF ZOOLOGY, Issue 1 2005Calum MacNeil Abstract Predation between invading and native species can produce patterns of exclusion and coexistence. Dikerogammarus villosus, a Ponto-Caspian amphipod species, has invaded many central European freshwaters in the past decade, replacing native Gammarus amphipod species. For instance, the arrival of D. villosus in Holland has been accompanied by the decline of Gammarus duebeni and G. tigrinus populations within invaded systems. This study examined what may happen when D. villosus eventually encounters native Dutch populations of Gammarus pulex, and how factors such as microhabitat and food resource availability could contribute to a future species replacement or coexistence. A laboratory simulation of a lake/pooled area of river indicated that G. pulex and D. villosus differed in distribution within the same habitat, and showed that although the distribution of the native differed in the presence of the invader, the presence of the native had no effect on the distribution of the invader. Gammarus pulex suffered severe intraguild predation (IGP) from D. villosus in mixed species treatments with no reciprocal predation of D. villosus by G. pulex. This IGP occurred regardless of whether no alternative food resource was available (91% of the G. pulex population eliminated after 7 days), or alternative foods/prey were available to excess, such as leaf material (85%), chironomids (77%) or fish food flakes (74%). We conclude that although differential microdistribution of the two species could promote coexistence, the presence of alternative foods/prey resources, merely slow the rate of IGP and replacement of the native by the invader. Our study joins one of an increasing number emphasizing the potential damaging impacts of D. villosus on native communities. [source] Up against the edge: invasive species as testbeds for basic questions about evolution in heterogeneous environmentsMOLECULAR ECOLOGY, Issue 21 2009ROBERT D. HOLT Yogi Berra is often credited, with having opined that ,prediction is very difficult, especially about the future'. There is no discipline for which this statement holds with more force than invasion biology, where it has been historically very challenging to predict the fate of introduced species (Williamson 2006). Some species after introduction quickly go extinct. Other relatively similar species may persist, but with little spread from their initial beachheads. Yet others can become aggressive invaders, with devastating consequences for native communities and ecosystems. This lack of predictability may of course sometimes reflect a simple lack of knowledge, both about key features of a species' basic biology, and about the environmental and community milieu in which invasion occurs (Williamson 2006). However, unpredictability may also arise from a fundamental fact about populations of living organisms , they almost always contain genetic variation, and so are not fixed entities responding to an environmental template, but instead labile in how they cope with the environment, over many spatial and temporal scales. Chance vicissitudes in the origination, maintenance and spatial organization of genetic variation could play a large role in generating the observed unpredictability in the fates of introduced species. The degree to which a particular introduced species becomes ,invasive', to the extent of coming to the attention of worried land managers, governmental officials and the public , may reflect in part its capacity for adaptive evolution across a wide range of environmental conditions. [source] Acer negundo invasion along a successional gradient: early direct facilitation by native pioneers and late indirect facilitation by conspecificsNEW PHYTOLOGIST, Issue 3 2010Patrick Saccone Summary ,Here, we analysed the role of direct and indirect plant interactions in the invasion process of Acer negundo along a natural successional gradient in the Middle Rhone floodplain (France). We addressed two questions: What are the responses of the invasive Acer seedlings to native communities' effects along the successional gradient? What are the effects of the invasive Acer adult trees on the native communities? ,In the three communities (Salix, Acer and Fraxinus stands) we transplanted juveniles of the invasive and juveniles of the natives within the forest and in experimental gaps, and with and without the herb layer. We also quantified changes in understory functional composition, light, nitrogen and moisture among treatments. ,Acer seedlings were directly facilitated for survival in the Salix and Acer communities and indirectly facilitated for growth by adult Acer through the reduction of the abundance of highly competitive herbaceous competitors. ,We conclude that direct facilitation by the tree canopy of the native pioneer Salix is very likely the main biotic process that induced colonization of the invasive Acer in the floodplain and that indirect facilitation by adult conspecifics contributed to population establishment. [source] Altering Light and Soil N to Limit Phalaris arundinacea Reinvasion in Sedge Meadow RestorationsRESTORATION ECOLOGY, Issue 4 2008Basil V. Iannone III Abstract Efforts to eradicate invasive plants in restorations can unintentionally create conditions that favor reinvasion over the establishment of desired species, especially when remnant invasive propagules persist. Reducing resources needed by the invader for seedling establishment, however, may be an effective strategy to prevent reinvasion. Propagules of Phalaris arundinacea persist after removal from sedge meadow wetlands and reestablish quickly in posteradication conditions, hindering community restoration. A study was conducted in two experimental wetlands with controlled hydrologic regimes to determine if reducing light by sowing short-lived, nonpersistent native cover crops or immobilizing soil N by incorporating soil,sawdust amendments can prevent Phalaris reinvasion, allowing native communities to recover. A 10-species perennial target community and Phalaris were sown with high-diversity, low-diversity, or no cover crops in soils with or without sawdust, and seedling emergence, establishment, and growth were measured. High-diversity cover crops reduced light, decreasing Phalaris and target community seedling establishment by 89 and 57%, respectively. Short-term nitrogen reduction in sawdust-amended soils delayed Phalaris seedling emergence and decreased Phalaris seedling establishment by 59% but did not affect total target community seedling establishment. The target community reduced Phalaris seedling establishment as effectively as cover crops did. In plots where the target community was grown, amending soils with sawdust further reduced Phalaris seedling growth but not establishment. Results show that use of cover crops can reduce seedling establishment of desired species and is counterproductive to restoration goals. Further, establishing target species is more important and practical for limiting Phalaris reinvasion than is immobilizing nitrogen. [source] Adaptation and Appropriation on the Colonial Frontier: Indigenous Leadership in the Colombian Chocó, 1670,1808BULLETIN OF LATIN AMERICAN RESEARCH, Issue 2 2007CAROLINE A. WILLIAMS This article explores the consequences for the native population of the Colombian Chocó of the emergence, over the course of the eighteenth century, of an elite of caciques and indios mandones or principales whose functions of powers far exceeded those of the warrior chiefs that had traditionally acted as leaders of their people. Appointed for the purpose of facilitating the collection of tribute and the supply of labour to European settlers, caciques and mandones were almost universally rejected by native communities during the early phases of Spanish colonisation (c. 1630,1690), and they disappear from the historical record after Independence. Eighteenth-century sources, however, not only record the existence of a clearly defined elite of mandones or principales in villages across the region, but show these individuals engaging actively with the colonial authorities, on behalf of their communities, at local and audiencia levels. This article argues that, at a time of a much strengthened European presence in the region, caciques and mandones came to understand their roles in ways that were entirely different from those intended by the Spanish, and in so doing acquired the legitimacy that had eluded their seventeenth-century predecessors. Far from serving merely as intermediaries between settlers and indigenous populations, indios mandones acted as negotiators on behalf of the indigenous population, whose task was to defend and/or advance the interests of the communities they had been appointed to control. [source] | ||||||||||