12 research outputs found
Variation in plant-animal interactions along an elevational gradient of moist forest in a semiarid area of Brazil
Pollination and dispersal are critical ecological processes that directly affect the reproductive success of plants and are important for understanding the structure of plant communities. We compiled data on pollination and dispersal syndromes of 406 plant species distributed among different elevations in Area de Protecao Ambiental da Serra de Baturite (APASB) in northeastern Brazil. We aim to determine how the dispersal and pollination of the flora in the mountainous rainforest of APASB are affected by climate, relief and growth form. We hypothesized that plant community is comprised of different ecological groups based on biotic and abiotic syndromes. Melittophily was the most common (57%) pollination syndrome followed by non-specialized and ornithophily (7%). We found that 64% of species exhibited zoochory, 19% exhibited anemochory and 17% exhibited autochory. Pollination syndromes differed significantly only between types of growth form. Dispersal syndromes differed between topology, growth form and elevation. Six ecological groups were formed based on the interaction between dispersal-pollination and growth form, with predominantly zoochory in woody and anemochory in non-woody plants. Water availability may be the principal factor responsible for variation among dispersal syndromes. The proportion of ruderal species in the non-woody component explains the differences in syndromes between growth forms3012734CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP552213/2011-0; 479263/2011-6; 563537/2010-8PROCAD 157/2007PP1-0033-00025.01.00/1
Bee-flower association in the Neotropics: implications to bee conservation and plant pollination
Variation in plant-animal interactions along an elevational gradient of moist forest in a semiarid area of Brazil
Biologia floral e sistemas de reprodução em especies de Bulbophyllum (Orchidaceae) ocorrentes em mata de galeria, campo rupestre e floresta estacional
Orientador : João SemirDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Foram estudados a biologia floral, mecanismos de polinização e sistemas de reprodução em espécies de Bulbophyllum, ocorrentes em diferentes ambientes, como floresta estaciona I, campo rupestre e mata de galeria nos estados de São Paulo e Minas Gerais, Brasil. As espécies estudadas são polinizadas por fêmeas de espécies de diferentes famílias de Diptera, com elevado grau de especificidade entre as espécies de Bulbophyllum e seus polinizadores. Os mecanismos de polinização destas espécies estão adaptados ao ambiente de suas áreas de ocorrência,maximizando a eficiência de polinização nestes locais, hipotetizando uma seqüência de adaptações morfológicas florais, de grupos anterionnente típicos de matas fechadas, irradiando até ocuparem outros ambientes como áreas abertas de campo rupestre. Todas as espécies apresentam mecanismo de auto-incompatibilidade homomórfico gametofítico. As espécies que apresentam sobre posição nas épocas de floração são inter-compatíveis, porém existe uma série de mecanismos que evitam a hibridização natural entre espéciesAbstract: The floral biology, pollination mechanisms and breeding sistems in Bulbophy/lum species, occurring in different vegetation types as in semideciduous forests, campo rupestre and gallery forest, in São Paulo and Minas Gerais states, Brazil, have been studied. These species are polfinated by females of species belonging to differents Dipteran families, with a high degree of specificity between Bulbophy/lum species and their polfinators. Their pollination mechanisms are adaptated to the environment of the placa where they occur, increasing polfination efficiency in those areas. I hypotherize an adaptive sequence in floral morfology from groups previously typical of forests to those groups in open areas such as the "campo rupestre". Ali species have homomorphic gametophitic self-incompatibility. Species with overlaped flowering time are inter-compatible, however there are several mechanisms that prevent hybridization between inter-fertile speciesMestradoMestre em Ecologi
Biosystematic studies in Hoffmannseggella H.G. Jones (Orchidaceae: Laeliinae) occuring in altitude rocky complexes of Brazil
Orientadores: João Semir, Vera Nisaka SolferiniTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo:Um estudo biossistemático foi realizado no gênero neotropical e endêmico do Brasil, Hoffmannseggella H.G. Jones. Este gênero é caracterizado por ser exclusivamente rupícola e apresentar flores de cores variadas, vívidas e contrastantes. As espécies estão distribuídas ao longo dos complexos rupestres de altitude, principalmente na região sudeste (MG, RJ e ES) e nordeste (BA). Foram descritos os padrões de distribuição geográfica para 34 espécies de Hoffmannseggella e três espécies de Dungsia, por meio de técnicas de georeferenciamento. Os resultados indicaram a formação de quatro subconjuntos de espécies: Chapada Diamantina - BA, centro-sul e centro-norte da Cadeia do Espinhaço - MG, e Complexos Rupestres do RJ/ES. As análises de PAE (Parsimony Analysis of Endemicity) e Modelagem Ecológica indicaram 12 áreas prioritárias para conservação, além de três áreas complementares para garantir a manutenção e sobrevivência destas espécies. São apresentados os resultados da datação molecular com ênfase em Hoffmannseggella, incluindo gêneros relacionados, sob uma perspectiva histórico-evolutiva. O cenário biogeográfico e histórico mais provável em Laeliinae, indica o surgimento e confinamento das espécies basais do grupo na América Central no Mioceno, com posterior irradiação de grupos derivados para a América do Sul, através da ligação parcial entre Ilhas da ¿Proto América Central¿. Os principais eventos de cladogênese em Hoffmannseggella não estão associados a áreas específicas, mas a múltiplos eventos associados à expansão e retração de áreas campestres ocorridas entre o Plioceno e o Pleistoceno. Foram realizados estudos de biologia floral e ecologia da polinização em oito espécies de Hoffmannseggella, com atenção aos mecanismos de isolamento reprodutivo entre espécies sincronopátricas. As espécies são polinizadas por himenópteros de diferentes famílias, com sistemas de polinização não específicos e baseados no engano do polinizador, contrariando suposições anteriores que caracterizavam estas espécies como ornitófilas. O estudo dos sistemas reprodutivos de 13 espécies em 36 diferentes populações revelou que a maioria das espécies é auto-incompatível, porém uma mesma espécie pode apresentar diferentes sistemas reprodutivos dependendo da população. A quebra da autoincompatibilidade em algumas espécies está fortemente associada à ocorrência da poliploidia, situação relativamente comum em Angiospermas, mas descrita pela primeira vez em Orchidaceae. A quebra da auto-incompatibilidade parece conferir vantagens ao estabelecimento de linhagens poliplóides em Hoffmannseggella, pois estas espécies apresentam mecanismos de auto-polinização espontânea. Foi realizado um estudo cromossômico, no qual foram obtidas contagens inéditas para 12 espécies e dois híbridos naturais em 24 diferentes populações, enfatizando a importância da poliploidia para a evolução deste grupo. Algumas espécies apresentaram citótipos, que foram discutidos sob uma visão citogeográfica e evolutiva, com ênfase nos principais mecanismos associados ao estabelecimento de complexos poliplóides. A poliploidia é um fenômeno relativamente recente em Hoffmannseggella, e surgiu independentemente várias vezes ao longo da sua história evolutiva. É descrita uma nova espécie, H. viridiflora, morfologicamente relacionada com as espécies de escapos curtos, flores pequenas e amarelas, ocorrentes no Planalto de Diamantina - MG. Por fim é apresentada uma visão biossistemática geral e conservacionista que revela os principais problemas associados à manutenção de áreas naturais com grande diversidade de espécies de HoffmannseggellaAbstract: A biosystematic study of the neotropical and Brazilian endemic genus Hoffmannseggella H. G. Jones was carried out. This genus is characterized by rupiculous habit, with varied-contrasting flowers colors. These species are distributed at high altitude rocky complexes, mainly in the Southeast (MG, RJ and ES) and Northeast (BA). The geographic distribution patterns of 34 Hoffmannseggella and three Dungsia species by GIS techniques were described. The results point to four sub-sets of species groups: Chapada Diamantina - BA, Northern and Southern part of Central area of the Espinhaço Range ¿ MG and rocky complexes of RJ/ES. Parsimony analysis of endemicity and ecological modeling indicated 12 priority areas for conservation and more three complementary areas to guarantee the species survival for a long time. The results of molecular dating are presented, with emphasis on Hoffmannseggella, including related genera, in a historical-evolutive perspective. The most probable biogeographic and historical scenario in Laeliinae points to the origin and confinement of basal species in Central America in the Miocene, with posterior irradiation of derivated groups to South America, through a partial link by islands in ¿Proto Central America¿. The main cladogenesis events in Hoffmannseggella are not associated with specific areas, but happen in multiple events associated to the expansion and retraction of open vegetation in the Plio-Pleistocene. Floral biology and pollination ecology studies were carried out in eight Hoffmannseggella species, with attention to the reproductive isolation mechanisms between sincronopatric species. Hoffmannseggella species are pollinated by small bees (Hymenoptera) of different families, with unspecific and deceit based pollination systems that discredit previous suppositions that characterized Hoffmannseggella as ornithophilous. Breeding system studies of 13 species and 36 different populations revealed that most species are self-compatible, but the same species can present different breeding systems depending on the population. The break up of self-incompatibility in some species is associated to polyploidy, and this phenomenon is relatively frequent in Angiosperms, but had been never described in orchids. Selfcompatibility in polyploid species can confer advantages in establishment of polyploid lineages. A review of chromosome numbers in Hoffmannseggella, show new counts for 12 species and two natural hybrids in 24 different populations, with emphasis in the importance of polyploidy for the evolution of this group. Some species presented different cytotypes, and this is discussed in a cytogeographic and evolutive perspective, with emphasis on the main factors related with establishment of polyploid complexes. Polyploidy is a recent phenomenon in Hoffmannseggella, but can appear independently many times in its evolutionary history. A new species, H. viridiflora, is described and morphologically related to species with short racemes, yellow and smaller flowers, occurring at the Diamantina Plateau - MG. Finally, we present a general biosystematic and conservationist view, which points the main problems associated with the maintenance of natural areas with high diversity of Hoffmannseggella speciesDoutoradoDoutor em Ecologi
Placement of Kuhlmanniodendron Fiaschi & Groppo in Lindackerieae (Achariaceae, Malpighiales) confirmed by analyses of rbcL sequences, with notes on pollen morphology and wood anatomy
The phylogenetic placement of Kuhlmanniodendron Fiaschi & Groppo (Achariaceae) within Malpighiales was investigated with rbcL sequence data. This genus was recently created to accommodate Carpotroche apterocarpa Kuhlm., a poorly known species from the rainforests of Espirito Santo, Brazil. One rbcL sequence was obtained from Kuhlmanniodendron and analyzed with 73 additional sequences from Malpighiales, and 8 from two closer orders, Oxalidales and Celastrales, all of which were available at Genbank. Phylogenetic analyses were carried out with maximum parsimony and Bayesian inference; bootstrap analyses were used in maximum parsimony to evaluate branch support. The results confirmed the placement of Kuhlmanniodendron together with Camptostylus, Lindackeria, Xylotheca, and Caloncoba in a strongly supported clade (posterior probability = 0.99) that corresponds with the tribe Lindackerieae of Achariaceae (Malpighiales). Kuhlmanniodendron also does not appear to be closely related to Oncoba (Salicaceae), an African genus with similar floral and fruit morphology that has been traditionally placed among cyanogenic Flacourtiaceae (now Achariaceae). A picrosodic paper test was performed in herbarium dry leaves, and the presence of cyanogenic glycosides, a class of compounds usually found in Achariaceae, was detected. Pollen morphology and wood anatomy of Kuhlmanniodendron were also investigated, but both pollen (3-colporate and microreticulate) and wood, with solitary to multiple vessels, scalariform perforation plates and other features, do not seem to be useful to distinguish this genus from other members of the Achariaceae and are rather common among the eudicotyledons as a whole. However, perforated ray cells with scalariform plates, an uncommon wood character, present in Kuhlmanniodendron are similar to those found in Kiggelaria africana (Pangieae, Achariaceae), but the occurrence of such cells is not mapped among the angiosperms, and it is not clear how homoplastic this character could be.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP[2000/07401-0]FAPESP[2006/03170-0]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade de São Paulo (USP)Universidade de São Paulo USP-ProIPCNPq (GDE)[200682/2006-7]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Virginia Commonwealth University (VCU)Virginia Commonwealth University (VCU)Carl Tryggers StiftelseCarl Tryggers StiftelseHelge Axson Johnsons StiftelseHelge Axson Johnsons Stiftels
Placement of kuhlmanniodendron fiaschi & groppo in lindackerieae (achariaceae, malpighiales) confirmed by analyses of rbcL sequences, with notes on pollen morphology and wood anatomy
The phylogenetic placement of Kuhlmanniodendron Fiaschi & Groppo (Achariaceae) within Malpighiales was investigated with rbcL sequence data. This genus was recently created to accommodate Carpotroche apterocarpa Kuhlm., a poorly known species from the rainforests of Espírito Santo, Brazil. One rbcL sequence was obtained from Kuhlmanniodendron and analyzed with 73 additional sequences from Malpighiales, and 8 from two closer orders, Oxalidales and Celastrales, all of which were available at Genbank. Phylogenetic analyses were carried out with maximum parsimony and Bayesian inference; bootstrap analyses were used in maximum parsimony to evaluate branch support. The results confirmed the placement of Kuhlmanniodendron together with Camptostylus, Lindackeria, Xylotheca, and Caloncoba in a strongly supported clade (posterior probability = 0.99) that corresponds with the tribe Lindackerieae of Achariaceae (Malpighiales). Kuhlmanniodendron also does not appear to be closely related to Oncoba (Salicaceae), an African genus with similar floral and fruit morphology that has been traditionally placed among cyanogenic Flacourtiaceae (now Achariaceae). A picrosodic paper test was performed in herbarium dry leaves, and the presence of cyanogenic glycosides, a class of compounds usually found in Achariaceae, was detected. Pollen morphology and wood anatomy of Kuhlmanniodendron were also investigated, but both pollen (3-colporate and microreticulate) and wood, with solitary to multiple vessels, scalariform perforation plates and other features, do not seem to be useful to distinguish this genus from other members of the Achariaceae and are rather common among the eudicotyledons as a whole. However, perforated ray cells with scalariform plates, an uncommon wood character, present in Kuhlmanniodendron are similar to those found in Kiggelaria africana (Pangieae, Achariaceae), but the occurrence of such cells is not mapped among the angiosperms, and it is not clear how homoplastic this character could be2862737CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP200682/2006-72000/07401-0; 2006/03170-
Pollen-based characterization of montane forest types in north-eastern Brazil
International audienc