Página 1 dos resultados de 181 itens digitais encontrados em 0.044 segundos

‣ Effect of invader removal: pollinators stay but some native plants miss their new friend

Ferrero, Victoria; Castro, Sílvia; Costa, Joana; Acuña, Paola; Navarro, Luis; Loureiro, J.
Fonte: Springer Science Publicador: Springer Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Removal of invasive species often benefits biological diversity allowing ecosystems’ recovery. However, it is important to assess the functional roles that invaders may have established in their new areas to avoid unexpected results from species elimination. Invasive animal-pollinated plants may affect the plant–pollination interactions by changing pollinator availability and/or behaviour in the community. Thus, removal of an invasive plant may have important effects on pollinator community that may then be reflected positive or negatively on the reproductive success of native plants. The objective of this study was to assess the effect of removing Oxalis pescaprae, an invasive weed widely spread in the Mediterranean basin, on plant–pollinator interactions and on the reproductive success of co-flowering native plants. For this, a disturbed area in central Portugal, where this species is highly abundant, was selected. Visitation rates, natural pollen loads, pollen tube growth and natural fruit set of native plants were compared in the presence of O. pes-caprae and after manual removal of their flowers. Our results showed a highly resilient pollination network but also revealed some facilitative effects of O. pes-caprae on the reproductive success of co-flowering native plants. Reproductive success of the native plants seems to depend not only on the number and diversity of floral visitors...

‣ So many visitors and so few pollinators: variation in insect frequency and effectiveness governs the reproductive success of an endemic milkwort

Castro, Sílvia; Loureiro, J.; Ferrero, Victoria; Silveira, Paulo; Navarro, Luis
Fonte: Springer Science Publicador: Springer Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
58.618115%
Plant–pollinator interactions are one of the most important and variable mutualisms having major implications for plant fitness. The present study evaluates the interactions between an endemic milkwort, Polygala vayredae, and its floral visitors by studying the temporal variability, foraging behaviour and effectiveness of floral visitors in three populations during three consecutive years. The flowers were visited by a diverse array of insects, totalling 24 different species. However, only four species were effective pollinators, depositing pollen on stigmas after one visit, while the remaining species behaved as nectar robbers, secondary nectar robbers or nectar thieves and were completely ineffective for pollination. Among the effective pollinators, two groups with distinct foraging behaviours were observed: the nectar collecting long-tongued bees Bombus pascuorum and Anthophora sp. and the pollen collectors Eucera longicornis and Halictus sp. No significant differences were observed among pollinators in their efficiency in pollen deposition on stigmas, but significant differences were observed in the foraging behaviour between nectarivorous and pollen collectors. Variation in the abundance and assemblage of floral visitors was observed at the temporal scale and among populations...

‣ História natural e interação flores-besouros em espécies de Cerrado; Natural history and flower-beetle interactions in Cerrado species

Paulino Neto, Hipolito Ferreira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 11/09/2009 Português
Relevância na Pesquisa
49.689023%
Interações planta-animal, tais como polinização, são a chave de processos ecológicos in muitas comunidades terrestres. O estudo de quem interage com quem é uma importante ferramenta para se entender os processos ecológicos e evolucionários. Em algumas comunidades tropicais, mais de um quarto de todas as espécies de planta pode ser polinizado por besouros. Eles são um grupo de inseto muito antigo e diversificado e eles interagem com angiospermas desde o período de suas origens e princípio da diversificação. Adicionalmente, a interação entre besouros e recursos florais provém singular oportunidade para se avaliar a complexidade de interações e a possibilidade de generalização como a tendência para plantas para usar uma enorme proporção da fauna de besouros visitantes como polinizadores, ou especialização com plantas usando uma proporção relativamente pequena da fauna disponível de visitantes como polinizadores. A distribuição espacial de espécies vegetais tem sido considerada um importante componente na determinação de interações planta-animal, sendo esperado que muitos padrões observados nestes sistemas resultem de variações na distribuição de recursos vegetais. A disponibilidade de recursos florais apresenta variações espaço-temporais que podem influenciar a eficiência dos polinizadores do ponto de vista quantitativo...

‣ Uma ferramenta para análise de redes de interações polinizador-planta aplicada ao portal IABIN-PTN.; A tool for analysis of plant-pollinator interactions networks applied the portal IABIN-PTN.

Lopes, Paulo Venancio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 13/04/2012 Português
Relevância na Pesquisa
57.91528%
O planeta está perdendo rapidamente sua biodiversidade, e isto se dá em boa medida pelo crescimento da população humana. Com ela cresceu a demanda por alimentos e matérias primas, e por conseqüência, aumentou a quantidade de terras usadas para sua produção. Esta demanda por terras aráveis e a busca por minérios fez com que a natureza entrasse em crise e a perda dos polinizadores, principalmente as abelhas, sem dúvida merece destaque. Isto por que estas espécies são responsáveis por um importante serviço de ecossistemas, a polinização, tanto para produção de alimentos quanto nas áreas naturais. Para encontrar soluções para o declínio dos polinizadores, os pesquisadores coletam dados sobre as ocorrências de espécies que auxiliem na conservação e no uso sustentado da biodiversidade. A manipulação da grande quantidade de dados coletados demanda o apoio da computação e ensejou a criação de uma nova área denominada informática para biodiversidade (biodiversity informatics), que se dedica à pesquisa e desenvolvimento de ferramentas que cobrem desde a digitalização até a análise dos dados. Uma categoria importante de dados de biodiversidade é a dos dados sobre as interações entre as espécies...

‣ Habitat heterogeneity and pollinators: Bees in fragmented landscapes (Hymenoptera : Apidae)

Patricio, Gleiciani Buerger; Gomig, Elizandra Goldoni
Fonte: California State University Publicador: California State University
Tipo: Artigo de Revista Científica Formato: 605-618
Português
Relevância na Pesquisa
58.185586%
This text presents the main studies that report the effect of habitat degradation upon plant-pollinator interactions and the importance of the presence of native vegetation remnants to pollinators, which leads to the need for conservation measures.

‣ Functional Diversity of Plant–Pollinator Interaction Webs Enhances the Persistence of Plant Communities

Fontaine, Colin; Dajoz, Isabelle; Meriguet, Jacques; Loreau, Michel
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
58.93444%
Pollination is exclusively or mainly animal mediated for 70% to 90% of angiosperm species. Thus, pollinators provide an essential ecosystem service to humankind. However, the impact of human-induced biodiversity loss on the functioning of plant–pollinator interactions has not been tested experimentally. To understand how plant communities respond to diversity changes in their pollinating fauna, we manipulated the functional diversity of both plants and pollinators under natural conditions. Increasing the functional diversity of both plants and pollinators led to the recruitment of more diverse plant communities. After two years the plant communities pollinated by the most functionally diverse pollinator assemblage contained about 50% more plant species than did plant communities pollinated by less-diverse pollinator assemblages. Moreover, the positive effect of functional diversity was explained by a complementarity between functional groups of pollinators and plants. Thus, the functional diversity of pollination networks may be critical to ecosystem sustainability.

‣ Presence of yeasts in floral nectar is consistent with the hypothesis of microbial-mediated signaling in plant-pollinator interactions

Pozo, María I; de Vega, Clara; Canto, Azucena; Herrera, Carlos M
Fonte: Landes Bioscience Publicador: Landes Bioscience
Tipo: Artigo de Revista Científica
Publicado em /11/2009 Português
Relevância na Pesquisa
58.501426%
Olfactory floral signals are significant factors in plant-pollinator mutualisms. Recently, unusual fermentation odors have been described in the nectar and flowers of some species. Since yeasts are common inhabitants of many angiosperms nectars, this raises the possibility that nectar yeasts may act as causal agents of fermentation odors in flowers and, therefore, as possible intermediate agents in plant signaling to pollinators. A recent field study has reported that nectar yeasts were quite frequent in floral nectar across three different regions in Europe and America, where they reached high densities (up to 105 cells/mm3). Yeast incidence in floral nectar differed widely across plant host species in all sampling sites. A detailed study currently in progress on one of the species surveyed in that study (Helleborus foetidus, Ranunculaceae) has detected that, in addition to interespecific differences in yeast incidence, there is also a strong component of variance in yeast abundance that takes place at the subindividual level (among flowers of the same plant, among nectaries of the same flower). If yeast metabolism is eventually proved to contribute significantly to floral scent, then multilevel patchiness in the distribution of nectar yeasts (among species...

‣ Private channels in plant-pollinator mutualisms

Soler, Catherine; Proffit, Magali; Chen, Chun; Hossaert-McKey, Martine
Fonte: Landes Bioscience Publicador: Landes Bioscience
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
59.10555%
Volatile compounds often mediate plant-pollinator interactions, and may promote specialization in plant-pollinator relationships, notably through private channels of unusual compounds. Nevertheless, the existence of private channels, i.e., the potential for exclusive communication via unique signals and receptors, is still debated in the literature. Interactions between figs and their pollinating wasps offer opportunities for exploring this concept. Several experiments have demonstrated that chemical mediation is crucial in ensuring the encounter between figs and their species-specific pollinators. Indeed, chemical messages emitted by figs are notably species- and developmental stage-specific, making them reliable cues for the pollinator. In most cases, the species-specificity of wasp attraction is unlikely to result from the presence of a single specific compound. Nevertheless, a recent paper on the role of scents in the interaction between Ficus semicordata and its pollinating wasp Ceratosolen gravelyi showed that a single compound, 4-methylanisole, is the main signal compound in the floral scent, and is sufficient by itself to attract the obligate pollinator. Mainly focusing on these results, we propose here that a floral scent can act as a private channel...

‣ The promise of genomics in the study of plant-pollinator interactions

Clare, Elizabeth L; Schiestl, Florian P; Leitch, Andrew R; Chittka, Lars
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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Flowers exist in exceedingly complex fitness landscapes, in which subtle variation in each trait can affect the pollinators, herbivores and pleiotropically linked traits in other plant tissues. A whole-genome approach to flower evolution will help our understanding of plant-pollinator interactions.

‣ Context-dependency of arbuscular mycorrhizal fungi on plant-insect interactions in an agroecosystem

Barber, Nicholas A.; Kiers, E. Toby; Hazzard, Ruth V.; Adler, Lynn S.
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 05/09/2013 Português
Relevância na Pesquisa
59.43995%
Plants interact with a variety of other community members that have the potential to indirectly influence each other through a shared host plant. Arbuscular mycorrhizal fungi (AMF) are generally considered plant mutualists because of their generally positive effects on plant nutrient status and growth. AMF may also have important indirect effects on plants by altering interactions with other community members. By influencing plant traits, AMF can modify aboveground interactions with both mutualists, such as pollinators, and antagonists, such as herbivores. Because herbivory and pollination can dramatically influence plant fitness, comprehensive assessment of plant–AMF interactions should include these indirect effects. To determine how AMF affect plant–insect interactions, we grew Cucumis sativus (Cucurbitaceae) under five AMF inoculum treatments and control. We measured plant growth, floral production, flower size, and foliar nutrient content of half the plants, and transferred the other half to a field setting to measure pollinator and herbivore preference of wild insects. Mycorrhizal treatment had no effect on plant biomass or floral traits but significantly affected leaf nutrients, pollinator behavior, and herbivore attack. Although total pollinator visitation did not vary with AMF treatment...

‣ Spatial Heterogeneity Regulates Plant-Pollinator Networks across Multiple Landscape Scales

Moreira, Eduardo Freitas; Boscolo, Danilo; Viana, Blandina Felipe
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 09/04/2015 Português
Relevância na Pesquisa
59.10505%
Mutualistic plant-pollinator interactions play a key role in biodiversity conservation and ecosystem functioning. In a community, the combination of these interactions can generate emergent properties, e.g., robustness and resilience to disturbances such as fluctuations in populations and extinctions. Given that these systems are hierarchical and complex, environmental changes must have multiple levels of influence. In addition, changes in habitat quality and in the landscape structure are important threats to plants, pollinators and their interactions. However, despite the importance of these phenomena for the understanding of biological systems, as well as for conservation and management strategies, few studies have empirically evaluated these effects at the network level. Therefore, the objective of this study was to investigate the influence of local conditions and landscape structure at multiple scales on the characteristics of plant-pollinator networks. This study was conducted in agri-natural lands in Chapada Diamantina, Bahia, Brazil. Pollinators were collected in 27 sampling units distributed orthogonally along a gradient of proportion of agriculture and landscape diversity. The Akaike information criterion was used to select models that best fit the metrics for network characteristics...

‣ Constructing more informative plant–pollinator networks: visitation and pollen deposition networks in a heathland plant community

Ballantyne, G.; Baldock, Katherine C. R.; Willmer, P. G.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em 07/09/2015 Português
Relevância na Pesquisa
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Interaction networks are widely used as tools to understand plant–pollinator communities, and to examine potential threats to plant diversity and food security if the ecosystem service provided by pollinating animals declines. However, most networks to date are based on recording visits to flowers, rather than recording clearly defined effective pollination events. Here we provide the first networks that explicitly incorporate measures of pollinator effectiveness (PE) from pollen deposition on stigmas per visit, and pollinator importance (PI) as the product of PE and visit frequency. These more informative networks, here produced for a low diversity heathland habitat, reveal that plant–pollinator interactions are more specialized than shown in most previous studies. At the studied site, the specialization index was lower for the visitation network than the PE network, which was in turn lower than for the PI network. Our study shows that collecting PE data is feasible for community-level studies in low diversity communities and that including information about PE can change the structure of interaction networks. This could have important consequences for our understanding of threats to pollination systems.

‣ The role of indirect plant-plant interactions via shared pollinators: a combined experimental and theoretical study in species-rich temperate grasslands

Hanoteaux, Sven
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
Português
Relevância na Pesquisa
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Anthropogenic activities are rapidly changing the world. The ongoing climate change (and its associated shifts in flowering phenologies), biological invasions and increased fragmentation of ecosystems are all inducing rapid changes in structural characteristics of plant communities. In communities, where many species depend on the service of pollinators for their reproduction, changes in species composition, floral densities and spatial distribution will undoubtedly further affect plant-pollinator interactions. Due to the interdependence of plant and pollinator species for their reproduction, plant-pollinator interactions are central in the maintenance of both plant and pollinator species and hence of biodiversity in many ecosystems. Therefore, understanding how structural characteristics of plant communities are affecting plant-pollinator interactions, would enable a better anticipation of the ecological consequences of destructive human activities. The present thesis investigated the impact of changing structural characteristics of European grassland plant communities on plant-pollinator interactions and on the outcome of indirect plant-plant interactions mediated through shared pollinators. Firstly, a spatially explicit model was used to theoretically examine the interplay between the densities and the spatial distribution of two differently attractive species on the plant species survival. Secondly...

‣ Generalizaci??n en las interacciones entre plantas y polinizadores

G??mez Reyes, Jos?? Mar??a
Fonte: Sociedad de Biolog??a de Chile Publicador: Sociedad de Biolog??a de Chile
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
58.84726%
Hasta fechas muy recientes, la mayor??a de los estudios te??ricos y emp??ricos sobre la evoluci??n de la relaci??n entre las plantas y sus polinizadores han asumido que estos sistemas est??n altamente especializados, es decir, cada especie vegetal es visitada por s??lo unos cuantos polinizadores relacionados filogen??ticamente como fruto de la selecci??n impuesta por ellos. La omnipresencia de especializaci??n se ha derivado de aceptar el principio del polinizador m??s eficiente, seg??n el cual una planta debe especializarse en el polinizador m??s eficaz y/o m??s abundante cuando su disponibilidad es predecible. Muchos estudios han encontrado realmente que los polinizadores ejercen selecci??n fenot??pica sobre rasgos reproductivos de las plantas. Sin embargo, igual de evidente es el hecho de que muchas especies vegetales son polinizadas por conjuntos numerosos y taxon??micamente diversos de polinizadores. Estas observaciones sugieren que en realidad los sistemas de polinizaci??n son generalistas. La generalizaci??n es producida y mantenida por varios factores ecol??gicos entre los que destacan la variaci??n espacial y la fluctuaci??n temporal de la identidad de los polinizadores m??s importantes, la similitud en la eficiencia y preferencia por los rasgos florales por parte de polinizadores diferentes...

‣ Interação planta-polinizador em espécies sincronopátricas de psychotria (rubiaceae); Plant-pollinator interactions in syncronopatric species of psychotria (rubiaceae)

Mesquita Neto, José Neiva
Fonte: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Biodiversidade Vegetal (ICB); Instituto de Ciências Biológicas - ICB (RG) Publicador: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Biodiversidade Vegetal (ICB); Instituto de Ciências Biológicas - ICB (RG)
Tipo: Dissertação Formato: application/pdf
Português
Relevância na Pesquisa
69.214766%
Plant-pollinator interactions in syncronopatric species of Psychotria (Rubiaceae). Psychotria species are commonly found in the understory of forested areas in tropical regions, and are important components for the functioning of these ecosystems. Many species of the genus are sympatric and bloom during the same period, being considered potentially syncronopatrics. For this reason, this genus has been considered as a good model to infer general patterns and mechanisms of speciation in the tropics. In the first paper of this dissertation, the interactions between potentially sympatric species of Psychotria and their pollinators were analyzed in order to verify the possible existence of sharing, specialization or generalization of pollinators and plants in the analyzed system. Then, data of secondary studies that contained identifying pollinators of Psychotria were analyzed From these data, we generated graphs and analyzes of interaction networks and niche overlap. Altogether, nine species of Psychotria and 25 species of pollinators of occurrence in the Atlantic Forest were included in the analyzes. The plant with the most generalist network is Psychotria tenuinervis and the pollinators with the highest proportion of links and consequently with more important role in the network belonged orders Lepidoptera and Hymenoptera. Psychotria species showed niche overlap in pollination and pollinator sharing. The period of greatest intensity of flowering coincided with the rainy season in the Atlantic Forest...

‣ Interacciones planta-polinizador desde la perspectiva de los polinizadores: diversidad floral, reproducción de abejas solitarias y su especialización; Plant-pollinator interactions from the pollinator´s perspective: floral diversity, solitary bee reproduction and its specialization

Dorado, Jimena
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2011 Português
Relevância na Pesquisa
89.21112%
La mayoría de los estudios planta-polinizador se centran en las plantas; en esta tesis fueron estudiadas desde la perspectiva de los polinizadores. Primero se evaluó la relación diversidadestabilidad para la producción floral como recurso para los polinizadores a lo largo de una temporada de floración. Los resultados mostraron una relación positiva que permite evaluar la generalidad de esta relación. Además, se evaluó el efecto de medidas ecológicas simples y comúnmente utilizadas, como la diversidad y abundancia floral, sobre el éxito reproductivo de los polinizadores, obteniéndose una respuesta especie específica. Existen dos mecanismos que explican la ampliación del nicho poblacional, pero solo uno de ellos ha sido evaluado proponiendose como el mecanismo general. Aquí, se evaluaron ambos mecanismos sobre varias especies de abeja con resultados diferentes a los reportados previamente, ya que ambos mecanismos operan. Por último, se evaluó cuán confiables son las inferencias sobre las especies raras en las redes planta-polinizador ya que podrían estar sesgadas por el tipo de muestreo utilizado para construirlas. Este estudio demostró que el sesgo existe y que aumenta con la rareza de las especies. Esta tesis permitió avanzar en el conocimiento de las interacciones planta-polinizador...

‣ Floral advertisement scent in a changing plant-pollinators market

Filella Cubells, Iolanda; Primante, Clara; Llusià Benet, Joan; Martín González, Ana M.; Seco Guix, Roger; Farré Armengol, Gerard; Rodrigo Domínguez, Anselm; Bosch Gras, Jordi; Peñuelas, Josep
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2013 Português
Relevância na Pesquisa
58.9521%
Plant-pollinator systems may be considered as biological markets in which pollinators choose between different flowers that advertise their nectar/pollen rewards. Although expected to play a major role in structuring plant-pollinator interactions, community-wide patterns of flower scent signals remain largely unexplored. Here we show for the first time that scent advertisement is higher in plant species that bloom early in the flowering period when pollinators are scarce relative to flowers than in species blooming later in the season when there is a surplus of pollinators relative to flowers. We also show that less abundant flowering species that may compete with dominant species for pollinator visitation early in the flowering period emit much higher proportions of the generalist attractant β-ocimene. Overall, we provide a first community-wide description of the key role of seasonal dynamics of plant-specific flower scent emissions, and reveal the coexistence of contrasting plant signaling strategies in a plant-pollinator market.

‣ The role of floral traits in structuring plant-pollinator interactions

Primante, Clara
Fonte: [Barcelona] : Universitat Autònoma de Barcelona, Publicador: [Barcelona] : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2015 Português
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89.75534%
Les interaccions planta-pol·linitzador són un component essencial de la biodiversitat i la funció ecològica dels ecosistemes terrestres. Un dels principals objectius de l'ecologia de la pol·linització és descriure aquestes interaccions i comprendre els factors subjacents a la seva estructura. En aquesta tesi doctoral es presenten els resultats dels estudis duts a terme durant tres anys en una comunitat mediterrània de plantes i els seus insectes pol·linitzadors al parc natural del Garraf (NE Espanya). En el capítol 1 es van registrar les interaccions planta-pol·linitzador i es van mesurar diferents trets morfològics, fenològics i ecològics de les especies de plantes i pol·linitzadors en un intent d'establir quins d'aquest trets estructuren les relacions planta-pol·linitzador. Es van registrar 14.713 contactes entre les principals 23 espècies de plantes i 221 espècies de pol·linitzadors, que van representar 960 interaccions específiques. Trobem que un tret ecològic (densitat de flors) i un tret fenològic (temps de floració) de les plantes van ser els principals factors que expliquen les interaccions observades. Trets florals, com la restricció de la corol·la i el pol·len i la producció de nèctar per flor...

‣ A phylogenetic study of pollinator conservatism among sexually deceptive orchids

Mant, J; Schiestl, Florian; Peakall, Rodney; Weston, Peter
Fonte: Society for the Study of Evolution Publicador: Society for the Study of Evolution
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
58.90264%
Orchids of the genus Chiloglottis are pollinated through the sexual deception of male wasps mainly from the genus Neozeleboria (Tiphiidae: Thynninae). The orchids mimic both the appearance and sex pheromones of wingless female thynnines but provide no reward to the deceived males. Despite the asymmetry of this interaction, strong pollinator specificity is typical. Such plant-pollinator interactions would seem to be relatively flexible in the plant's adaptive response to variation in the local pollinator resource. However, we present DNA sequence data on both orchids and wasps that demonstrate a pattern of pollinator conservatism operating at a range of taxonomic levels. Sequence data from the wasps indicate 15 of 16 Chiloglottis pollinators are closely related members of one clade of Thynninae. A pattern of congruence between orchid and wasp phylogenies is also demonstrated below the generic level, such that related orchids tend to use related thynnine wasps as specific pollinators. Comparative physiological data on the wasp responses to the floral scents of two Chiloglottis species and one outgroup, Arthrochilus, indicate similar attractive volatile chemicals are used by related orchid taxa. By extension, we infer a similarity of sex pheromone signals among related thynnines. Thus...

‣ Detrimental effects of volcanic ash deposition on bee fauna and plant-pollinator interactions

Morales,Carolina L.; Saez,Agustín; Arbetman,Marina P; Cavallero,Laura; Aizen,Marcelo A.
Fonte: Ecología austral Publicador: Ecología austral
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2014 Português
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68.494785%
Volcanic eruptions are large-scale natural disturbances, which can negatively affect insect fauna and the ecological interactions in which they are involved. The 2011 eruption of the volcanic complex Puyehue Cordón-Caulle (PCC) produced the deposition of 950 million tons of ash on Argentine Patagonia, creating an ash layer of varying thickness. Although experimental studies confirmed that PCC volcanic ash negatively affects survival and behavior in many insect taxa, including bees, the effects of ash deposition on the plant-pollinator interactions (PPI) of this group of insects in natural landscapes remained untested. We evaluated the effect of the gradient of increasing ash layer thickness (0-15cm) on: (1) number of wild bees visiting flowers and total bee richness in 16 raspberry fields after the eruption, (2) number of native (Bombus dahlbomii) and invasive (B. terrestris and B. ruderatus) bumble bees foraging on wild flowers in 10 sites before and after the eruption, and (3) the proportion of “triggered” flowers (i.e. papilionaceous flowers visited for first time by large bees) in 32 populations of the invasive shrub scotch broom (Cytisus scoparius), before and after the eruption. With the increase of ash deposition...