BIOLOGIA REPRODUTIVA DE Passiflora cincinnata MAST. (PASSIFLORACEAE) NA REGIÃO DE PETROLINA-PE

O presente trabalho foi desenvolvido de setembro de 2004 a abril de 2006, em área experimental de Passiflora cincinnata em Petrolina-PE, objetivando verificar a fenologia, a biologia floral, o comportamento e a freqüência dos visitantes florais em condições de cultivo. P. cincinnata apresentou antese diurna (06h), com tempo de vida da flor de aproximadamente nove horas. Com relação à produção de néctar, esta variou de 176ml a 204ml, com concentração variando de 38% a 40%. O processo de curvatura foi sincronizado entre os estiletes de uma mesma flor, sendo que o tempo médio de curvatura de 2 horas. Entre as flores avaliadas (n=164), verificou-se que 47,6% apresentavam estiletes sem curvaturas, 25,0% apresentavam estiletes parcialmente curvos e 27,4% apresentavam estiletes totalmente curvos, indicando que 72,6% das flores de P. cincinnata seriam funcionalmente masculinas e, portanto não produziriam frutos. Entre os visitantes florais encontram-se abelhas, vespas, mariposas, borboletas e beija-flores. Com relação ao horário de visitas, verificou-se que as flores foram mais visitadas entre 06h e 09h. Analisando a freqüência de visitas, verificou-se que as abelhas do gênero Xylocopa foram registradas ao longo de todo o dia na área de cultivo convencional, exceto nos horários entre 10h e 11h e entre 14h e 15h, porém concentrando suas visitas entre 15h e 16h. Já Trigona spinipes Fab. realizou visitas somente no período da manhã, entre 06h e 09h, enquanto Apis mellifera L. concentrou suas visitas das 10h às 11h. Já em cultivo orgânico, T. spinipes foi registrada em todos os horários pilhando néctar, enquanto que as visitas de Xylocopa grisescens Lepeletier foram registradas somente no início da manhã. Para minimizar os impactos dos pilhadores, cinco atrativos diferentes foram ofertados, onde os tratamentos café com açúcar (F=245,54; gl=1,151;

Vegetative propagation of Rhaphiodon echinus Schauer (Lamiaceae): effects of the period of cutting in rooting, cuttings arrangement and IBA concentrations for seedlings production

One of the tendencies in the floriculture sector, whether in modern landscaping or floral art, is related to the insertion of innovations in the sector, mainly of native origin. For this it is necessary to establish strategies that favor the introduction of these materials. Among the species that present ornamental potential, Rhaphiodon echinus Schauer has been outstanding for groundcover; however it is necessary to establish the proper propagation protocol for the species. In this sense, the objective was to evaluate the vegetative propagation process of this species considering the period of cutting in rooting, cuttings arrangement and IBA concentrations for seedlings production. The experiment was carried out in a sub-split plots scheme with the period of cutting in rooting in the plots (30 and 60 days), the cuttings arrangement (horizontal and vertical) in the subplots and the IBA concentrations (0; 1,000; 2,000 and 4,000 ppm) in sub-subplots. The following variables were evaluated: survival cuttings, percentage of rooted cuttings, number of sprouts per cuttings, average length of the largest root, root volume, shoot dry biomass and root dry biomass. There was a significant interaction between the period of cutting in rooting and the cuttings arrangement for survival cuttings and rooted cuttings; between the period of cutting in rooting and the concentration of IBA for shoot dry and between the cuttings arrangement and concentration and IBA for the percentage of rooted cuttings, number of sprouts per cuttings and root dry biomass. For average length of the largest root and root volume there was a significant effect for period of cutting in rooting and IBA concentrations individually. The period of cutting in rooting of 30 days is the most suitable for rooting the cuttings. In relation of the cuttings arrangement the most indicated is vertical. Finally, the concentration of 1,000 ppm of IBA can be indicated for the propagation of R. echinus by the cutting process

Negative impacts of dominance on bee communities: Does the influence of invasive honey bees differ from native bees?

Invasive species can reach high abundances and dominate native environments. One of the most impressive examples of ecological invasions is the spread of the African subspecies of the honey bee throughout the Americas, starting from its introduction in a single locality in Brazil. The invasive honey bee is expected to more negatively impact bee community abundance and diversity than native dominant species, but this has not been tested previously. We developed a comprehensive and systematic bee sampling scheme, using a protocol deploying 11,520 pan traps across regions and crops for three years in Brazil. We found that invasive honey bees are now the single most dominant bee species. Such dominance has not only negative consequences for abundance and species richness of native bees but also for overall bee abundance (i.e., strong “numerical” effects of honey bees). Contrary to expectations, honey bees did not have stronger negative impacts than other native bees achieving similar levels of dominance (i.e., lack of negative “identity” effects of honey bees). These effects were markedly consistent across crop species, seasons and years, and were independent from land-use effects. Dominance could be a proxy of bee community degradation and more generally of the severity of ecological invasions.info:eu-repo/semantics/publishedVersio

Negative impacts of dominance on bee communities: Does the influence of invasive honey bees differ from native bees?

Invasive species can reach high abundances and dominate native environments. One of the most impressive examples of ecological invasions is the spread of the African subspecies of the honey bee throughout the Americas, starting from its introduction in a single locality in Brazil. The invasive honey bee is expected to more negatively impact bee community abundance and diversity than native dominant species, but this has not been tested previously. We developed a comprehensive and systematic bee sampling scheme, using a protocol deploying 11,520 pan traps across regions and crops for three years in Brazil. We found that invasive honey bees are now the single most dominant bee species. Such dominance has not only negative consequences for abundance and species richness of native bees but also for overall bee abundance (i.e., strong “numerical” effects of honey bees). Contrary to expectations, honey bees did not have stronger negative impacts than other native bees achieving similar levels of dominance (i.e., lack of negative “identity” effects of honey bees). These effects were markedly consistent across crop species, seasons and years, and were independent from land-use effects. Dominance could be a proxy of bee community degradation and more generally of the severity of ecological invasions.info:eu-repo/semantics/publishedVersio

Mutually beneficial pollinator diversity and crop yield outcomes in small and large farms

Ecological intensification, or the improvement of crop yield through enhancement of biodiversity, may be a sustainable pathway toward greater food supplies. Such sustainable increases may be especially important for the 2 billion people reliant on small farms, many of which are undernourished, yet we know little about the efficacy of this approach. Using a coordinated protocol across regions and crops, we quantify to what degree enhancing pollinator density and richness can improve yields on 344 fields from 33 pollinator-dependent crop systems in small and large farms from Africa, Asia, and Latin America. For fields less than 2 hectares, we found that yield gaps could be closed by a median of 24% through higher flower-visitor density. For larger fields, such benefits only occurred at high flower-visitor richness.Worldwide, our study demonstrates that ecological intensification can create synchronous biodiversity and yield outcomes.Fil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rio Negro. Centro de Investigaciones y Transferencia de Rio Negro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Rio Negro; ArgentinaFil: Carvalheiro, Luísa G.. Universidade do Brasília; BrasilFil: Vaissière, Bernard E.. Centre de Recherche de Nantes. Institut National de la Recherche Agronomique; FranciaFil: Gemmill Herren, Barbara. Food and Agriculture Organization of the United Nations; ItaliaFil: Hipólito, Juliana. Universidade Federal da Bahia; BrasilFil: Freitas, Breno M.. Universidade Federal do Ceará; BrasilFil: Ngo, Hien T.. Intergovernmental Platform on Biodiversity and Ecosystem Services; AlemaniaFil: Azzu, Nadine. Food and Agriculture Organization of the United Nations; ItaliaFil: Sáez, Agustín. 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: Åström, Jens. Norwegian Institute for Nature Research; NoruegaFil: An, Jiandong. Chinese Academy of Agricultural Sciences; ChinaFil: Blochtein, Betina. Pontificia Universidade Católica do Rio Grande do Sul; BrasilFil: Buchori, Damayanti. Bogor Agricultural University; IndonesiaFil: Chamorro García, Fermín J.. Universidad Nacional de Colombia; ColombiaFil: Da Silva, Fabiana Oliveira. Universidade Federal de Sergipe; BrasilFil: Devkota, Kedar. Institute of Agriculture and Animal Science; NepalFil: De Fátima Ribeiro, Márcia. Embrapa Semiárido; BrasilFil: Freitas, Leandro. Jardim Botânico do Rio de Janeiro; BrasilFil: Gaglianone, Maria C.. Universidade Estadual Do Norte Fluminense Darcy Ribeiro; BrasilFil: Goss, Maria. University of Zimbabwe; ZimbabueFil: Irshad, Mohammad. Honey Bee Research Institute; PakistánFil: Kasina, Muo. Kenya Agricultural and Livestock Research Organisation-Sericulture; KeniaFil: Pacheco Filho, Alípio J.S.. Universidade Federal do Ceará; BrasilFil: Piedade Kiill, Lucia H.. Embrapa Semiárido; BrasilFil: Kwapong, Peter. University of Cape Coast; GhanaFil: Parra, Guiomar Nates. Universidad Nacional de Colombia; ColombiaFil: Pires, Carmen. Parque Estação Biológica; BrasilFil: Pires, Viviane. Instituto do Meio Ambiente e Recursos Hídrico; BrasilFil: Rawal, Ranbeer S.. G.B. Pant Institute of Himalayan Environment and Development; IndiaFil: Rizali, Akhmad. University of Brawijaya; IndonesiaFil: Saraiva, Antonio M.. Universidade de Sao Paulo; BrasilFil: Veldtman, Ruan. South African National Biodiversity Institute; Sudáfrica. Stellenbosch University; SudáfricaFil: Viana, Blandina F.. Universidade Federal da Bahia; BrasilFil: Witter, Sidia. Fundação Estadual de Pesquisa Agropecuária; BrasilFil: Zhang, Hong. Chinese Academy of Agricultural Sciences; Chin