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Institution

National University of Comahue

EducationNeuquén, Argentina
About: National University of Comahue is a(n) education organization based out in Neuquén, Argentina. It is known for research contribution in the topic(s): Population & Species richness. The organization has 2242 authors who have published 4498 publication(s) receiving 87157 citation(s). The organization is also known as: UNCOMA & UNCo.


Papers
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Journal ArticleDOI
29 Mar 2013-Science
TL;DR: Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation.
Abstract: The diversity and abundance of wild insect pollinators have declined in many agricultural landscapes. Whether such declines reduce crop yields, or are mitigated by managed pollinators such as honey bees, is unclear. We found universally positive associations of fruit set with flower visitation by wild insects in 41 crop systems worldwide. In contrast, fruit set increased significantly with flower visitation by honey bees in only 14% of the systems surveyed. Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation. Visitation by wild insects and honey bees promoted fruit set independently, so pollination by managed honey bees supplemented, rather than substituted for, pollination by wild insects. Our results suggest that new practices for integrated management of both honey bees and diverse wild insect assemblages will enhance global crop yields.

1,550 citations

Journal ArticleDOI
14 May 2010-Science
TL;DR: Global extinction projections were validated with local extinctions observed from 1975 to 2009 for regional biotas on four other continents, suggesting that lizards have already crossed a threshold for extinctions caused by climate change.
Abstract: It is predicted that climate change will cause species extinctions and distributional shifts in coming decades, but data to validate these predictions are relatively scarce Here, we compare recent and historical surveys for 48 Mexican lizard species at 200 sites Since 1975, 12% of local populations have gone extinct We verified physiological models of extinction risk with observed local extinctions and extended projections worldwide Since 1975, we estimate that 4% of local populations have gone extinct worldwide, but by 2080 local extinctions are projected to reach 39% worldwide, and species extinctions may reach 20% Global extinction projections were validated with local extinctions observed from 1975 to 2009 for regional biotas on four other continents, suggesting that lizards have already crossed a threshold for extinctions caused by climate change

1,282 citations

Journal ArticleDOI
TL;DR: A highly significant correlation between the effect sizes of fragmentation on pollination and reproductive success suggests that the most proximate cause of reproductive impairment in fragmented habitats may be pollination limitation.
Abstract: The loss and fragmentation of natural habitats by human activities are pervasive phenomena in terrestrial ecosystems across the Earth and the main driving forces behind current biodiversity loss. Animal-mediated pollination is a key process for the sexual reproduction of most extant flowering plants, and the one most consistently studied in the context of habitat fragmentation. By means of a meta-analysis we quantitatively reviewed the results from independent fragmentation studies throughout the last two decades, with the aim of testing whether pollination and reproduction of plant species may be differentially susceptible to habitat fragmentation depending on certain reproductive traits that typify the relationship with and the degree of dependence on their pollinators. We found an overall large and negative effect of fragmentation on pollination and on plant reproduction. The compatibility system of plants, which reflects the degree of dependence on pollinator mutualism, was the only reproductive trait that explained the differences among the species' effect sizes. Furthermore, a highly significant correlation between the effect sizes of fragmentation on pollination and reproductive success suggests that the most proximate cause of reproductive impairment in fragmented habitats may be pollination limitation. We discuss the conservation implications of these findings and give some suggestions for future research into this area.

842 citations

Journal ArticleDOI
TL;DR: Although the primary cause of the accelerating increase of the pollinator dependence of commercial agriculture seems to be economic and political and not biological, the rapid expansion of cultivation of many pollinator-dependent crops has the potential to trigger future pollination problems for both these crops and native species in neighboring areas.
Abstract: Summary The prospect that a global pollination crisis currently threatens agricultural productivity has drawn intense recent interest among scientists, politicians, and the general public [1–5]. To date, evidence for a global crisis has been drawn from regional or local declines in pollinators themselves [6–9] or insufficient pollination for particular crops [9, 10]. In contrast, our analysis of Food and Agriculture Organization (FAO) [11] data reveals that the global population of managed honey-bee hives has increased ∼45% during the last half century and suggests that economic globalization, rather than biological factors, drives both the dynamics of the global managed honey-bee population and increasing demands for agricultural pollination services [12]. Nevertheless, available data also reveal a much more rapid (>300%) increase in the fraction of agriculture that depends on animal pollination during the last half century, which may be stressing global pollination capacity. Although the primary cause of the accelerating increase of the pollinator dependence of commercial agriculture seems to be economic and political and not biological, the rapid expansion of cultivation of many pollinator-dependent crops has the potential to trigger future pollination problems for both these crops and native species in neighboring areas. Such environmental costs merit consideration during the development of agriculture and conservation policies.

790 citations

Journal ArticleDOI
01 Aug 2009-Ecology
TL;DR: Both bee abundance and species richness were significantly, negatively affected by disturbance, however, the magnitude of the effects was not large and the only disturbance type showing a significant negative effect, habitat loss and fragmentation, was statistically significant only in systems where very little natural habitat remains.
Abstract: Pollinators may be declining globally, a matter of concern because animal pollination is required by most of the world's plant species, including many crop plants. Human land use and the loss of native habitats is thought to be an important driver of decline for wild, native pollinators, yet the findings of published studies on this topic have never been quantitatively synthesized. Here we use meta-analysis to synthesize the literature on how bees, the most important group of pollinators, are affected by human disturbances such as habitat loss, grazing, logging, and agriculture. We obtained 130 effect sizes from 54 published studies recording bee abundance and/or species richness as a function of human disturbance. Both bee abundance and species richness were significantly, negatively affected by disturbance. However, the magnitude of the effects was not large. Furthermore, the only disturbance type showing a significant negative effect, habitat loss and fragmentation, was statistically significant only in systems where very little natural habitat remains. Therefore, it would be premature to draw conclusions about habitat loss having caused global pollinator decline without first assessing the extent to which the existing studies represent the status of global ecosystems. Future pollinator declines seem likely given forecasts of increasing land-use change.

740 citations


Authors

Showing all 2242 results

NameH-indexPapersCitations
Thomas T. Veblen8730622151
Jens-Christian Svenning8553128460
Adrian C. Newton7445321814
Martin Søndergaard7223619651
Uwe Rau6849615906
Thomas Kirchartz6221211407
Marcelo A. Aizen6117717606
Lawrence D. Harder5712711870
Daniel R. Perez5519812208
Fernando Hiraldo532198620
Thomas Kitzberger5012612985
Saul A. Cunningham5014516385
Claudio M. Ghersa451617422
Stella M. Alzamora441495262
Martin A. Nuñez421515144
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20229
2021281
2020311
2019294
2018271
2017300