1,721,063 research outputs found
The Multicolored Asian Lady Beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), Disperses the Hemlock Woolly Adelgid, Adelges tsugae (Annand) (Hemiptera: Adelgidae)
No full textLeppanen, Christy, Simberloff, Daniel (2018): The Multicolored Asian Lady Beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), Disperses the Hemlock Woolly Adelgid, Adelges tsugae (Annand) (Hemiptera: Adelgidae). The Coleopterists Bulletin 72 (3): 612-613, DOI: 10.1649/0010-065X-72.3.612, URL: http://dx.doi.org/10.1649/0010-065x-72.3.61
Why some exotic species are deeply integrated into local cultures while others are reviled
No full textOne key challenge for invasive species management is finding support from local communities. Without local support, management plans can be severely compromised. What makes people support or reject management of invasive species can be linked to their perception of the target invasive species. In other words, it can be harder to control invasive species that are assimilated into the local community. We identify five factors associated with how quickly invasive species can become culturally assimilated. These factors are arrival time, economic impact, aesthetic value, effect on human health, and origin of nonnative species and of human immigrants. We suggest that understanding how these factors contribute to the incorporation of nonnative species into local cultures is important in determining effective control measures. In this vein, publicly accessible educational programs explaining the problems that invasive species produce will be required to implement effective invasive species management.Fil: Nuñez, Martin Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Dimarco, Romina Daniela. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Simberloff, Daniel. University of Tennessee; Estados Unido
A framework for understanding human-driven vegetation change
No full textDespite a major research focus on human-mediated reshuffling of plant communities, no coherent framework unites the numerous types of changes in abundances and distributions of native and non-native species that are driven by human activities. Human driven vegetation change can occur through: non-native species introductions; population outbreaks or collapses; range expansions or contractions; and range shifts of both native and non-native species. Boundaries among these different types of floristic changes are not always distinct because of an overlap in the ecological, climatic, and anthropogenic processes that underpin them. We propose a new framework that connects various human-mediated causes of vegetation change, highlights the spatial scales at which drivers act and the temporal scale at which plant assemblages respond, and provides critical insights for identifying and appropriately managing these changes
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Disparate responses of above- and belowground properties to soil disturbance by an invasive mammal
Full text linkIntroduced mammalian herbivores can negatively affect ecosystem structure and function if they introduce a novel disturbance to an ecosystem. For example, belowground foraging herbivores that bioturbate the soil, may alter process rates and community composition in ecosystems that lack native belowground mammalian foragers. Wild boar (Sus scrofa) disturb the soil system and plant community via their rooting behavior in their native range. Given their size and the numbers in their populations, this disturbance can be significant in forested ecosystems. Recently, wild boar were introduced to Patagonian forests lacking native mammalian herbivores that forage belowground. To explore how introduced wild boar might alter forested ecosystems, we conducted a large-scale wild boar exclusion experiment in three different forest types (Austroducedrus chilensis forest, Nothofagus dombeyi forest, and shrublands). Wild boar presence altered plant composition and structure, reducing plant biomass 3.8-fold and decreasing both grass and herb cover relative to areas where wild boar were excluded. Decomposition rates and soil compaction also declined by 5% in areas where boar had access; however, rooting had no effect on soil nutrient stocks and cycling. Interestingly, there were no differences in wild boar impacts on different forest types. We found that after 3-years of exclusion, belowground foraging by wild boar had a larger impact on plant community structure and biomass than it did on soil nutrient processes.Fil: Barrios Garcia Moar, Maria Noelia. Administración de Parques Nacionales. Delegación Regional Patagonia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Classen, Aimee T.. University of Tennessee; Estados UnidosFil: Simberloff, Daniel. University of Tennessee; Estados Unido
Current mismatch between research and conservation efforts: The need to study co-occurring invasive plant species
Full text linkThough biological invasion studies have proliferated in recent decades, a consistent emphasis remains on the study of single-species invasions. Here, we juxtapose the number of invasive plants reported as co-occurring within conservation habitats in one of the most comprehensive global conservation management databases (The Nature Conservancy’s Conservation Projects) with the number of published studies that address impacts of co-occurring invasive plants. We reviewed 86 conservation projects and 153 peer-reviewed publications and found that only one-third of studies mentioned co-occurring invaders, although over two-thirds of habitats were multiply invaded, indicating researchers are more likely to study single invaders, even though conservation managers are more often faced with multiple invaders in a given habitat. Of those studies focused on multiple invasives, the majority did not attempt to differentiate impacts caused by species when found alone or with other invaders and instead either treated co-occurring invaders together as a single, undifferentiated group or compared impacts between invasive plant monocultures. Less than 6% of all studies analyzed invader interactions. The high prevalence of co-occurring invasive plants should encourage more research on multiple invaders, which may better inform prioritization of which species to manage. Specifically, we suggest research on how effects of multiple invaders differ from those of single invaders, what types of interactions (facilitative, competitive, neutral) are most commonly found between invaders, and what effects interactions might have on the overall impact (additive or non-additive) of the individual invader. Though we acknowledge the challenge of studying multiple invaders, there is a critical need to address these questions to make invasion research more relevant to conservation programs.Fil: Kuebbing, Sara E.. University Of Tennessee; Estados UnidosFil: Nuñez, Martin Andres. University Of Tennessee; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Simberloff, Daniel. University Of Tennessee; Estados Unido
Invasive Species: To eat or not to eat, that is the question
Full text linkManaging invasive species is a current challenge for biodiversity conservation. A recurring recent suggestion is that by harvesting nonnatives for human consumption, people can control invasive populations. Even though humans may be able to control or eradicate certain populations of nonnative species by harvesting them as food sources, several caveats should be considered before starting these programs. A prominent problem is that creating a market engenders pressure to maintain that problematic species. Also, if the target species becomes an economic resource, people may try to recreate that market in previously uninvaded regions. Using invasive species as an economic resource may trigger the local community to protect these harmful species, to facilitate their incorporation into the local culture, and can generate severe management problems. As with other management programs, managers must know if the harvest actually reduces the target population. Mortality could produce a reduction in the population size or growth, or it could be compensatory, in which case removal of the harvested individuals would not affect population growth. However, in addition to possible control, there may be several benefits of this approach, including an opportunity for public outreach. Projects aiming at controlling invasives through human consumption should be carefully examined, as they may produce results opposite to those proposed.Fil: Nuñez, Martin Andres. University of Tennessee; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Kuebbing, Sara. University of Tennessee; Estados UnidosFil: Dimarco, Romina Daniela. University of Tennessee; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Simberloff, Daniel. University of Tennessee; Estados Unido
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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