scholarly journals The Impact of Copper on Non-Indigenous and Native Species of Suspension-Feeding Bivalves in Mission Bay, San Diego, California

2018 ◽  
Author(s):  
Brian Juhl
Keyword(s):  
Native Species ◽  
San Diego ◽  
Suspension Feeding ◽  
Mission Bay ◽  
The Impact

scholarly journals Diet composition of the invasive red-whiskered bulbul Pycnonotus jocosus in Mauritius

2010 ◽  
Vol 26 (3) ◽  
pp. 347-350 ◽  
Author(s):  
Jannie Fries Linnebjerg ◽  
Dennis M. Hansen ◽  
Nancy Bunbury ◽  
Jens M. Olesen
Keyword(s):  
Invasive Species ◽  
Introduced Species ◽  
Native Species ◽  
Diet Composition ◽  
Ecological Perspective ◽  
Positive Interactions ◽  
Invasional Meltdown ◽  
Ecological Processes ◽  
Successful Establishment ◽  
The Impact

Disruption of ecosystems is one of the biggest threats posed by invasive species (Mack et al. 2000). Thus, one of the most important challenges is to understand the impact of exotic species on native species and habitats (e.g. Jones 2008). The probability that entire ‘invasive communities’ will develop increases as more species establish in new areas (Bourgeois et al. 2005). For example, introduced species may act in concert, facilitating one another's invasion, and increasing the likelihood of successful establishment, spread and impact. Simberloff & Von Holle (1999) introduced the term ‘invasional meltdown’ for this process, which has received widespread attention since (e.g. O'Dowd 2003, Richardson et al. 2000, Simberloff 2006). Positive interactions among introduced species are relatively common, but few have been studied in detail (Traveset & Richardson 2006). Examples include introduced insects and birds that pollinate and disperse exotic plants, thereby facilitating the spread of these species into non-invaded habitats (Goulson 2003, Mandon-Dalger et al. 2004, Simberloff & Von Holle 1999). From a more general ecological perspective, the study of interactions involving introduced and invasive species can contribute to our knowledge of ecological processes – for example, community assembly and indirect interactions.

scholarly journals INTERCAMBIO TRASFRONTERIZO DE SERVICIOS DE SALUD Y MEDICINAS EN LA REGIÓN DE TIJUANA Y SAN DIEGO

2010 ◽  
Vol 5 (10) ◽  
pp. 303
Author(s):  
José G. Vargas-Hernández
Keyword(s):  
Health Care ◽  
Health Services ◽  
Regional Development ◽  
San Diego ◽  
Negative Consequences ◽  
Review Of The Literature ◽  
Border Area ◽  
Future Studies ◽  
Documentary Analysis ◽  
The Impact

Este trabajo tiene por objetivo analizar el intercambio fronterizo en la región Tijuana-San Diego de los servicios de atención médica, cuidados de la salud y medicamentos. Aun con un gran número de investigaciones y estudios, todavía se tienen muchos cuestionamientos con respecto al impacto de este intercambio en el desarrollo regional. El método empleado es exploratorio, analítico documental y de revisión de la literatura existente. En este trabajo se delimita el mercado trasfronterizo del sur de California y la zona fronteriza de Tijuana, las motivaciones de los usuarios y compradores, las principales barreras, características y tipología. Se enuncian algunas de las áreas para futuras investigaciones y finalmente se formulan algunas propuestas que tienen implicaciones en las políticas públicas. Este estudio arroja luz sobre la posibilidad de elevar los ingresos provenientes del comercio de los servicios de salud, mejorar la satisfacción de los usuarios y consumidores y mitigar las consecuencias negativas asociadas con el diseño de políticas y de iniciativas en los ámbitos multilateral, binacional, regional.    ABSTRACTThe objective of this article is to analyze the border exchange in the Tijuana-San Diego region of medical services, health care and medicines. Despite the numerous research studies conducted, there are still many questions regarding the impact from this exchange on regional development. The exploratory method, documentary analysis and a review of the literature were utilized. This article is focused on the transboundary market of southern California and the Tijuana border area, the motivations of users and buyers, the main barriers, characteristics and typology. Some areas for future studies are specified, and lastly, some proposals with implications for public policies are formulated. This study sheds light on the possibilities of increasing income from commerce in health services, improving the satisfaction of users and consumers, and mitigating the negative consequences associated with the design of policies and initiatives at the multilateral, binational and regional levels.

The Effect of Variables on Laboratory Termite Testing: Part 4—Test Block Species, Size, and Test Photoperiod

2021 ◽  
Vol 71 (2) ◽  
pp. 95-100
Author(s):  
G. B. Lindsey ◽  
T. L. Amburgey ◽  
H. M. Barnes
Keyword(s):  
Native Species ◽  
Wood Sample ◽  
Treated Wood ◽  
Reticulitermes Flavipes ◽  
Coptotermes Formosanus ◽  
Standard Laboratory ◽  
Yellow Pine ◽  
Southern Yellow Pine ◽  
The Impact ◽  
Standard Tests

Abstract The objective of this study was to determine the impact on termite feeding of wood sample size and species and test photoperiod in standard tests. Native species (Reticulitermes flavipes) and introduced species (Coptotermes formosanus) were tested in an American Wood-Preservers' Association E1 standard laboratory test. For testing involving treated wood, southern yellow pine was determined to be preferable to spruce based on its treatability and availability. Test blocks of 25 by 25 by 6 mm were deemed adequate for testing, with large blocks presenting difficulty with retrieval of termites to determine mortality and smaller blocks being consumed too rapidly by the termites in the test. Photoperiod comparisons were not significantly different for R. flavipes; however, C. formosanus indicated a preference for 100 percent darkness. Therefore, the recommendation is to maintain tests using each species in a 100 percent dark environment.

scholarly journals Effect of Urbanization on Vegetation in Riparian Area: Plant Communities in Artificial and Semi-Natural Habitats

2019 ◽  
Vol 12 (1) ◽  
pp. 204 ◽  
Author(s):  
Yang Cao ◽  
Yosihiro Natuhara
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
Native Species ◽  
Impervious Surface ◽  
Riparian Areas ◽  
Natural Habitats ◽  
Artificial Habitats ◽  
Management Actions ◽  
Impact Of Urbanization ◽  
The Impact

Riparian areas are local hot spots of biodiversity that are vulnerable and easily degraded. Comparing plant communities in habitats with different degrees of urbanization may provide valuable information for the management and restoration of these vulnerable habitats. In this study, we explored the impact of urbanization on vegetation communities between artificial and semi-natural habitats within two rivers with different levels of development. We compared species richness, types of vegetation, and composition patterns of the plants in our study. In artificial habitats, the sites with relatively high levels of urbanization had the highest species richness, while in semi-natural habitats, the highest species richness was recorded in the less urbanized sites. Furthermore, every component of urbanization that contributed to the variation of species richness was examined in the current study. In artificial habitats, the proportion of impervious surface was the strongest predictor of the variation in species richness and was associated with the richness of alien, native, and riparian species. In semi-natural habitats, most of the richness of alien and native species were associated with the distance to the city center, and the number of riparian and ruderal species was significantly related to the proportion of impervious surface. Moreover, we found that a high level of urbanization was always associated with a large abundance of alien and ruderal species in both artificial and in semi-natural habitats. We recommend the methods of pair comparison of multiple rivers to analyze the impact of urbanization on plant species in riparian areas and have suggested various management actions for maintaining biodiversity and sustainability in riparian ecosystems.

The effect of increased ground-level habitat complexity on mouse population dynamics

2003 ◽  
Vol 30 (6) ◽  
pp. 565 ◽  
Author(s):  
A. D. Arthur ◽  
R. P. Pech ◽  
A. Drew ◽  
E. Gifford ◽  
S. Henry ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Native Species ◽  
Habitat Complexity ◽  
Habitat Structure ◽  
Ground Level ◽  
Low Complexity ◽  
Mouse Population ◽  
Introduced Predators ◽  
The Impact

We investigated experimentally the influence of habitat structure on the population dynamics of house mice. Three habitat types were used. In one, dense stands of regenerating cypress pine were felled and left in situ to cover at least 40% of experimental plots, providing high complexity at ground level; in another, dense stands of regenerating pine were left intact, providing low complexity at ground level; in the third, open grassland adjacent to dense stands of regenerating pine also provided low complexity at ground level. Mouse populations occurred at higher densities in felled pine plots compared with both the standing pine and grassland plots, consistent with the hypothesis that the presence of increased habitat complexity at ground level reduced the impact of predation. Even though populations responded to the felled pine, they dropped to very low densities over winter, suggesting that the habitat was still marginal for the persistence of mice, probably due to a lack of food. The results are discussed with reference to their implications for the influence that habitat structure may have on the impact of introduced predators on native species.

scholarly journals Crayfish plague affects juvenile survival and adult behaviour of invasive signal crayfish

Parasitology ◽  
2020 ◽  
Vol 147 (6) ◽  
pp. 706-714 ◽  
Author(s):  
John Rhidian Thomas ◽  
Chloe V. Robinson ◽  
Agata Mrugała ◽  
Amy R. Ellison ◽  
Emily Matthews ◽  
...  
Keyword(s):  
North American ◽  
Native Species ◽  
North American Species ◽  
Juvenile Survival ◽  
Signal Crayfish ◽  
Aphanomyces Astaci ◽  
The North ◽  
High Infection ◽  
Oomycete Pathogen ◽  
The Impact

AbstractThe spread of invasive, non-native species is a key threat to biodiversity. Parasites can play a significant role by influencing their invasive host's survival or behaviour, which can subsequently alter invasion dynamics. The North American signal crayfish (Pacifastacus leniusculus) is a known carrier of Aphanomyces astaci, an oomycete pathogen that is the causative agent of crayfish plague and fatal to European crayfish species, whereas North American species are considered to be largely resistant. There is some evidence, however, that North American species, can also succumb to crayfish plague, though how A. astaci affects such ‘reservoir hosts’ is rarely considered. Here, we tested the impact of A. astaci infection on signal crayfish, by assessing juvenile survival and adult behaviour following exposure to A. astaci zoospores. Juvenile signal crayfish suffered high mortality 4-weeks post-hatching, but not as older juveniles. Furthermore, adult signal crayfish with high-infection levels displayed altered behaviours, being less likely to leave the water, explore terrestrial areas and exhibit escape responses. Overall, we reveal that A. astaci infection affects signal crayfish to a much greater extent than previously considered, which may not only have direct consequences for invasions, but could substantially affect commercially harvested signal crayfish stocks worldwide.

scholarly journals Factors Influencing Movement of the Manila Dunes and Its Impact on Establishing Non-Native Species

2020 ◽  
Vol 12 (10) ◽  
pp. 1536
Author(s):  
Buddhika Madurapperuma ◽  
James Lamping ◽  
Michael McDermott ◽  
Brian Murphy ◽  
Jeremy McFarland ◽  
...  
Keyword(s):  
Native Species ◽  
North Coast ◽  
Vegetation Density ◽  
Dune Vegetation ◽  
Feature Extraction Method ◽  
Humboldt County ◽  
The North ◽  
Remote Sensing Techniques ◽  
Dynamic Communities ◽  
The Impact

Unmanned aerial vehicles (UAVs) are being widely used to monitor microtopographic and vegetation changes in coastal habitats using remote sensing techniques. Sand dune habitats are vital ecosystems along the North coast of Humboldt County in California. This study was conducted at the Manila Dunes, west of the Humboldt Coastal Nature Center, in Manila, California. Various factors influence dune movements, including vegetative stabilization and the creation of social trails. The purpose of this paper is to understand the dune movements in relation to social vs. established trails, vegetation density, topography, and also, mapping invasive vs. native species in the Mal-le’l Dunes area of the Humboldt Bay National Wildlife Refuge. A DJI Mavic Pro multicopter small unmanned aerial vehicle (UAV) was used to fly a 22.5-acre plot of the Manila Dunes. The images from this flight were used to create an orthomosaic image using a photogrammetry process (Structure-from-Motion (SfM)). From our analysis, the installation of trails lessened the impact of dune movements. Social trails digitized within the study site were found to have more local movements than the established trails when compared to movements across the entire site. We compared two methods of classification, viz., the object-based feature extraction method and a pixel-based supervised maximum likelihood classification method, in order to identify the best way to classify dune vegetation. In conclusion, this study is useful for providing baseline dune movement information that can aid in informing how trail and infrastructure constructions can be impacted in land management or in areas with dynamic communities of flora and fauna.

scholarly journals How to find a metapopulationThis review is one of a series dealing with some aspects of the impact of habitat fragmentation on animals and plants. This series is one of several virtual symposia focussing on ecological topics that will be published in the Journal from time to time.

2007 ◽  
Vol 85 (10) ◽  
pp. 1031-1048 ◽  
Author(s):  
D.A. Driscoll
Keyword(s):  
Native Species ◽  
Field Data ◽  
Spatial Dynamics ◽  
Metapopulation Dynamics ◽  
Data Sets ◽  
Fragmented Landscapes ◽  
Metapopulation Theory ◽  
Metapopulation Models ◽  
The Impact ◽  
Analytical Approaches

Where habitat loss and fragmentation is severe, many native species are likely to have reduced levels of dispersal between remnant populations. For those species to avoid regional extinction in fragmented landscapes, they must undergo some kind of metapopulation dynamics so that local extinctions are countered by recolonisation. The importance of spatial dynamics for regional survival means that research into metapopulation dynamics is essential. In this review I explore the approaches taken to examine metapopulation dynamics, highlight the analytical methods used to get the most information out of field data, and discover some of the major research gaps. Statistical models, including Hanski’s incidence function model (IFM) are frequently applied to presence–absence data, an approach that is often strengthened using long-term data sets that document extinctions and colonisations. Recent developments are making the IFM more biologically realistic and expanding the range of situations for which the model is relevant. Although accurate predictions using the IFM seem unlikely, it may be useful for ranking management decisions. A key weakness of presence–absence modelling is that the mechanisms underlying spatial dynamics remain inferential, so combining modelling approaches with detailed demographic research is warranted. For species where very large data sets cannot be obtained to facilitate statistical modelling, a demographic approach alone or with stochastic modelling may be the only viable research angle to take. Dispersal is a central process in metapopulation dynamics. Research combining mark–recapture or telemetry methods with model-selection procedures demonstrate that dispersal is frequently oversimplified in conceptual and statistical metapopulation models. Dispersal models like the island model that underlies classic metapopulation theory do not approximate the behaviour of real species in fragmented landscapes. Nevertheless, it remains uncertain if additional biological realism will improve predictions of statistical metapopulation models. Genetic methods can give better estimates of dispersal than direct methods and take less effort, so they should be routinely explored alongside direct ecological methods. Recent development of metacommunity theory (communities connected by dispersal) emphasises a range of mechanisms that complement metapopulation theory. Taking both theories into account will enhance interpretation of field data. The extent of metapopulation dynamics in human modified landscapes remains uncertain, but we have a powerful array of field and analytical approaches for reducing this knowledge gap. The most informative way forward requires that many species are studied in the same fragmented landscape by applying a selection of approaches that reveal complementary aspects of spatial dynamics.

scholarly journals The effects of introducing the Amazonian squirrel monkey on the behavior of the northeast marmoset

2015 ◽  
Vol 45 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Fátima Luciana Miranda CAMAROTTI ◽  
Valdir Luna da SILVA ◽  
Maria Adélia Borstelmann de OLIVEIRA
Keyword(s):  
Squirrel Monkey ◽  
Native Species ◽  
Callithrix Jacchus ◽  
Observation Time ◽  
Saimiri Sciureus ◽  
Significant Difference ◽  
Negative Effect ◽  
Total Observation Time ◽  
Total Observation ◽  
The Impact

The squirrel monkey Saimiri sciureus, an endemic primate of the Amazonian Basin, has been introduced in many localities of the Atlantic Forest biome. Introduced exotic species gain a competitive advantage in their new environment because of a lack of natural predators, competitors or diseases. This advantage can result in a reduction in the resources for the endemic species. The aims of this work were to evaluate the level of adaptation, and monitor the forms of interaction and the impact caused by S. sciureus on the behavior of the native species Callithrix jacchus in the Saltinho Biological Reserve, Tamandaré, Pernambuco, Brazil. The behavior was assessed by use of scan sampling method, every 5 min. A total of 382 h (191 h or 2,292 scans per group) of time sampling was performed. Sixteen interactions were recorded. The interaction index was low and represented 2.4% of the total observation time. Interactions were significantly higher during the dry season (58.5%) relative to the rainy season (41.5%). Callithrix jacchus was intolerant to the presence of S. sciureus and the last one was more tolerant during the interactions. In the presence of S. sciureus, C. jacchus eating, foraging, resting, socializing, and self-grooming behaviors were reduced while alertness was increased. Territorial behavior showed no significant difference. In the presence of S. sciureus, on average, the group of marmosets assembled at a higher layer of the forest stratum. The results might indicate a negative effect of S. sciureus on the native species, C. jacchus.

Prevention of invasive species in the context of lower secondary education

2019 ◽  
Vol 6 (2) ◽  
pp. 40-47
Author(s):  
Maria Balazova ◽  
Dana Blahutova ◽  
Terezia Valaskova
Keyword(s):  
Invasive Species ◽  
Biological Invasions ◽  
Native Species ◽  
Invasive Species Management ◽  
Prevention Education ◽  
Close Proximity ◽  
Invasive Organisms ◽  
Species Management ◽  
Potential Benefits ◽  
The Impact

Biological invasions are recognised as a potentially major threat to biodiversity and may have considerable economic and social effects. Public, including pupils, attitudes may have large implications for invasive species management in terms of prevention, early warning and eradication success, but significant is the relations between the lay public’s visions of nature, their knowledge about non-native species and their perceptions of invasive species management. The more direct experience people have with the impact of invasive species, the more likely they will be able to understand the potential benefits of management programmes. The aim of our work was to prepare educational materials about invasive organisms for elementary schools. Some of them were subsequently applied directly in practice as part of an excursion in a schoolyard in west Slovakia, where up to six species of invasive plants were identified in the close proximity to the school. Keywords: Biological invasions, prevention, education, excursion.

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