Made available in DSpace on 2016-04-28T14:56:18Z (GMT). No. of bitstreams: 1 Aline dos Santos Dias.pdf: 3422634 bytes, checksum: dc4b6e67281e315c9d0348b75c811d7d (MD5) Previous issue date: 2009-04-03 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / ?The epiphytes are plants that use trees as support without being connected to the ground. The epiphytes have wide geographical distribution and could be finding basically in most tropical rain forest, representing 50% of the neotropical vascular flora. The families more representative are Orchidaceae, Bromeliaceae, Araceae and Polypodiaceae. Despite the increase in the number of studies on the epiphytism in Brazil, information on this guild in the remaining forests of Rio de Janeiro state are still scarce. Thus, this study aimed to analyze the composition, richness and guild structure on a forest situated between 500 and 1500 meters over sea level (montana forest) in the Serra do ?rg?os National Park (RJ). In the 60 plots of 100 m2 (0.6 ha), all trees with DBH > 10.0 cm had their diameter and total height measured. All epiphytes were identified and their abundances were estimated for each class of height stipulated for the host trees. The relative frequencies of occurrence of species were calculated for the area as a whole and for host trees as well as for the host trees classes of height, canopy and trunk, and your value of importance calculated. Each species was classified according to their ecological category. The horizontal distribution of species was analyzed using the Morisita index and vertical by ?2 test. Relationship between the morphometric characteristics of host trees and richness and abundance of epiphytes were performed by simple regression analysis. We identified 84 species of epiphytes, in 28 genera and 9 families. The most representative families were Bromeliaceae, Araceae and Polypodicaeae. In this area, the epiphytes richness is considered high when compared with several studies in Brazil. The most frequent species were Microgramma squamulosa, Pleopeltis pleopeltifolia and P. hirsutissimum and a high number were considered rare species. Pleopeltis pleopeltifolia was more frequent in host trees, followed by P. hirsutissimum and M. squamulosa. These species also occurred in high frequencies in other studies, showing its wide geographical distribution and its importance in the composition of this guild. The species with higher importance are epiphytics P. hirsutissimum, P. pleopeltifolia and M. squamulosa, showing the high capacity of these species to occupy the host trees. Most epiphytes in this area (56% of species) are classified as holoepiphytes, as shown in other similar studies. For the horizontal distribution, random distribution pattern were observed for basically all high abundance epiphytes, indicating that this area has a wide availability of resources for the establishment of these species. In vertical distribution, we observed a significant difference in the occupation of the different classes of height of host trees for 53 of 84 species sampled. The highest occurrence of epiphytes was observed in the canopy. There were significant and positive relationship between height and total host trees with the richness and abundance of epiphytes, as well as between DBH and richness and abundance of epiphytes. Thus, the epiphytes respond directly to the structure of the forest where they are found, varying its parameters under different ecological characteristics with structure of forest formation. / ?As ep?fitas s?o vegetais que, durante toda a sua vida ou em algum est?gio dela, vivem sobre as ?rvores, utilizando-as como suporte, sem estarem ligadas ao solo. As ep?fitas possuem uma ampla distribui??o geogr?fica e s?o encontradas em praticamente todas as florestas ?midas, representando cerca de 50% de toda flora vascular neotropical. As fam?lias mais representativas s?o Orchidaceae, Bromeliaceae, Araceae e Polypodiaceae. Apesar do incremento no n?mero de estudos sobre o epifitismo no Brasil, informa??es sobre esta guilda nos remanescentes do Rio de Janeiro ainda s?o escassos. Desta forma, este estudo visou analisar a composi??o, riqueza e a estrutura das ep?fitas vasculares em um trecho de Floresta Ombr?fila Densa Montana do Parque Nacional da Serra dos ?rg?os (RJ). Foram demarcadas 60 parcelas de 100 m2 (0,6 ha), nas quais as ?rvores com DAP > 10,0 cm tiveram seu di?metro e altura total mensurados. Todas as ep?fitas encontradas nos for?fitos foram identificadas, tendo suas abund?ncias estimadas em cada classe de altura estipulada para os for?fitos. As freq??ncias relativas de ocorr?ncia das esp?cies foram calculadas para a ?rea como um todo, para os for?fitos e para as zonas de altura do for?fito, copa e fuste, al?m de terem seu valor de import?ncia calculado. Cada esp?cie foi classificada de acordo com sua categoria ecol?gica. A distribui??o horizontal das esp?cies foi analisada atrav?s do ?ndice de Morisita e a vertical pelo teste de ?2 . Rela??es entre as caracter?sticas morfom?tricas do for?fito e a riqueza e abund?ncia de ep?fitas foram efetuadas atrav?s da an?lise de regress?o simples. Foram identificadas 84 esp?cies de ep?fitas, de 28 g?neros e nove fam?lias. As fam?lias mais representativas foram Bromeliaceae, Araceae e Polypodicaeae. A riqueza de ep?fitas nesta ?rea pode ser considerada alta quando comparada com diversos estudos realizados no Brasil. As esp?cies mais freq?entes foram Microgramma squamulosa, Pleopeltis pleopeltifolia e P. hirsutissimum, sendo consideradas raras a maioria das esp?cies. Pleopeltis pleopeltifolia foi a mais frequente nos for?fitos, seguida de P. hirsutissimum e M. squamulosa. As esp?cies com maiores valores de import?ncia epif?tica foram P. hirsutissimum, P. pleopeltifolia e M. squamulosa, sendo clara a ampla capacidade de ocupa??o dos for?fitos por estas esp?cies. A maioria das ep?fitas nesta ?rea (56% das esp?cies) ? classificada como holoep?fitas, sendo este resultado semelhante a outros estudos. Para a distribui??o horizontal, praticamente todas as ep?fitas tiveram um padr?o de distribui??o aleat?rio, demonstrando, principalmente, que nesta ?rea h? uma ampla disponibilidade de recursos para o estabelecimento destas esp?cies. Na distribui??o vertical, foi observada uma diferen?a significativa na ocupa??o das classes de altura do for?fito para 53 esp?cies das 84 amostradas. A maior ocorr?ncia de ep?fitas foi observada na copa. Houve rela??o significativa e positiva entre a dimens?o dos for?fitos e a abund?ncia e a riqueza de ep?fitas. Assim, as ep?fitas responderam diretamente ? estrutura da floresta onde s?o encontradas, variando seus par?metros ecol?gicos de acordo com a estrutura da forma??o florestal.

Orientador: Adelita Aparecida Sartori Paoli / Banca: Luiz Antonio de Souza / Banca: Ismar Sebastião Moscheta / Resumo: Cactaceae distribui-se pelo continente americano, do sul e oeste do Canadá até o sul da Patagônia na Argentina e Chile. A família está inserida em Caryophyllales e possui cerca de 1.500 espécies. Epiphyllum phyllanthus (L.) Haw. é epífita obrigatória muito difundida na América do Sul, sendo a única espécie brasileira nativa de Epiphyllum Haw. A biologia reprodutiva em Cactaceae foi estudada em menos de 10% das espécies que a constituem e, esta limitada quantidade de dados, impede melhor entendimento dos mecanismos reprodutivos na família. Objetivou-se a realização de estudo morfológico e anatômico dos órgãos reprodutivos e da plântula de E. phyllanthus, através de: (i) análise morfoanatômica da flor; (ii) morfoanatomia e ontogenia do pericarpo e da semente e (iii) morfoanatomia da plântula. A flor é séssil, epígina com hipanto desenvolvido. Todos os verticilos florais apresentam epiderme unisseriada, glabra e estomatífera. O gineceu é sincárpico, com 9-10 carpelos, pluriovulado, de placentação parietal. O ovário possui feixes vasculares invertidos. A flor apresenta região nectarífera na face interna do hipanto. O óvulo é circinótropo, bitegumentado, crassinucelado, de funículo longo. O hipanto é de natureza receptacular. O fruto é do tipo cactídio de coloração róseo-roxo brilhante, superfície lisa e acumula concentração elevada de amido no pericarpo e na polpa, quando maduro. As sementes são campilótropas, pretas e de formato ovóide. A superfície externa ventral exibe relevo diferenciado, a região hilo-micropilar, de coloração esbranquiçada, onde ocorre arilo. O embrião é curvo com reserva lipoprotéica. Perisperma e endosperma persistem na semente madura, sem substâncias de reserva. A plântula é fanerocotiledonar e apresenta germinação epígea. Durante a germinação há hidratação e expansão de mucilagem na semente... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Cactaceae family is widely distributed in the American continents, from the south and west of Canada to the south of Patagonia (Argentina and Chile). It is included in Caryophyllales and has approximately 1,500 species. Epiphyllum phyllanthus (L.) Haw. exhibits an obligatory epiphytic habit and is widespread in South America. Additionally, it is the only Epiphyllum Haw. species that is indigenous to Brazil. Studies concerning the reproductive biology of Cactaceae have been conducted in no more than 10 percent of the taxa, and such a limited amount of data precludes the suitable comprehension of the reproductive mechanisms in the family. The present work was aimed at providing a morphoanatomical description of the reproductive organs and seedlings of Epiphyllum phyllanthus by means of (i) flower morphoanatomical analysis; (ii) morphoanatomical and ontogenic studies of the pericarp and seed, and (iii) morphoanatomical analysis of seedling in developing. It was observed that the sessile and epigynous flower exhibit a well-developed hypanthium. All the flower whorls has uniseriate epidermis. The syncarpous and pluriovulate gynoecium exhibit 9-10 carpels and parietal placentation. The ovary has inverted bundles and the flower showed the nectariferous region on the inner surface of the hypanthium. The ovule is circinotropous, bitegmic, crassinucelate, and has a long funiculus. The hypanthium exhibit receptacular origin. The bright pinkish-purplish "cactidio-type" fruit has a smooth surface and, when it is ripe, exhibits a high concentration of starch in the pericarp and pulp. The seed is campylotropous, black and ovoid. Its ventral outer surface presents a differentiated relief that is the whitish hilum-micropylar region, in which the aril occurs. The curved embryo contains lipoprotein reserves. Perisperm and endosperm persist in the mature seed without reserve substances... (Complete abstract click electronic access below) / Mestre

Floodplain lakes are strongly regulated by river connectivity because floodwaters exert strong influence on the water balance, the physical, chemical and biological limnological conditions, and the influx of contaminants. The Peace-Athabasca Delta (PAD) in northern Alberta (Canada) is a hydrologically complex landscape and is an important node in the upper Mackenzie River Drainage Basin. The ecological integrity of the PAD is potentially threatened by multiple environmental stressors, yet our understanding of the hydroecology of this large floodplain remains underdeveloped. Indeed, ever since the planning and construction of the WAC Bennett Dam (1960s), concerns have grown over the effects of upstream human activities on the lakes of the PAD. More recently, concerns over the health of the PAD have intensified and come to the fore of national and international dialogue due to water abstraction and mining and processing activities by the rapidly expanding oil sands industry centred in Fort McMurray Alberta. Currently, widespread perception is that upstream human activities have reduced water levels and frequency of flooding at the PAD, which have lowered nutrient availability and productivity of perched basin lakes, and have increased supply of pollutants from oil sands. However, these perceptions remain based on insufficient knowledge of pre-impact conditions and natural variability. Current and past relations between hydrology and limnology of PAD lakes are mostly undocumented, particularly during the important spring freshet period when the effects of river flood waters are strongest. Similarly, knowledge of the deposition of oil-sands- related contaminants in the PAD remains insufficient to determine whether anthropogenic activities have increased the deposition of important oil-sands-related contaminants such as polycyclic aromatic compounds (PACs) relative to natural processes. Such knowledge gaps must be filled to achieve effective monitoring, policy and governance concerning impacts of industrial development and the protection of human and environmental health within the PAD and Mackenzie drainage basin. This thesis examines the effects of river flooding (and the lack of) on water clarity, nutrients, chemistry, phytoplankton abundance, epiphyton community composition and the deposition of polycyclic aromatic compounds (PACs) in lakes of the Peace-Athabasca Delta. To determine the role of flooding on contemporary epiphytic diatom communities (an abundant and diverse guild of primary producers in PAD lakes), a field experiment was conducted examining the community composition and abundance of epiphytic diatoms in four PAD lakes. Two of these four lakes had received floodwaters that spring and two had not. Epiphytic diatom communities in each lake were sampled during the peak macrophyte biomass period (summer) from two macrophyte taxa (Potamogeton zosteriformis, P. perfoliatus var. richardsonii) and from polypropylene artificial substrates previously deployed that spring. A two-way analysis of similarity (ANOSIM) test identified that epiphytic diatom community composition differed between lakes that flooded and those that did not flood. From the use of similarity percentage (SIMPER) analysis, diatom taxa were identified that discriminate between flooded and non-flooded lakes. The relative abundance of ‘strong flood indicator taxa’ was used to construct an event-scale flood record spanning the past ~180 years using analyses of sedimentary diatom assemblages from a closed-drainage lake (PAD 5). Results were verified by close agreement with an independent paleo-flood record from a nearby flood-prone oxbow lake (PAD 54) and historical records. Comparison of epiphytic diatoms in flooded and non-flooded lakes in this study provides a promising approach to detect changes in flood frequency, and may have applications for reconstructing other pulse-type disturbances such as hurricanes and pollutant spills. Additionally, this study demonstrates that artificial substrates can provide an effective bio-monitoring tool for lakes of the PAD and elsewhere. To improve our understanding of the hydrolimnological responses of lake in the PAD to flooding, repeated measurements over three years (2003-05) were made on a series of lakes along a hydrological gradient. This allowed the role of river flooding to be characterized on limnological conditions of lakes and to identify the patterns and timescales of limnological change after flooding. River floodwaters elevate lake water concentrations of suspended sediment, total phosphorus (TP), SO4 and dissolved Si (DSi), and reduce concentrations of total Kjeldahl nitrogen (TKN), DOC and most ions. River flooding increases limnological homogeneity among lakes, because post-flood conditions are strongly affected by the river water properties. After floodwaters recede, limnological conditions become more heterogeneous among lakes in response to diversity of local basin influences (geology, slope, vegetation, depth, fetch, and biological communities and processes), and limnological changes occur at two distinct timescales. In the weeks to months after flooding, water clarity increases as suspended sediments and TP settle out of the water column. In the absence of flooding for many years to decades, evaporative concentration leads to an increase in most nutrients (TKN, inorganic N, and dissolved P), DOC and ions. Contrary to a prevailing paradigm, these results suggest that regular flooding is not required to maintain high nutrient concentrations. In light of anticipated declines in river discharge, limnological conditions in the southern Athabasca sector will become increasingly less dominated by the short-term effects of flooding, and resemble nutrient- and solute-rich lakes in the northern Peace sector that are infrequently flooded. To determine the roles of the Athabasca River and atmospheric transport as vectors for the deposition of PACs in the PAD, sediment cores spanning the last ~200 years were collected from three lakes within the delta. A closed-drainage basin elevated well above the floodplain (PAD 18) was selected to determine temporal patterns of change in PAC concentration due to atmospheric deposition and within-basin production of PACs. Known patterns of paleohydrological changes at the other two lakes (PAD 23 and 31) were used to assess the role of the Athabasca River in delivering PACs to the Athabasca Delta during the ~200 year. Well- dated sediment core samples were analysed for 52 alkylated and non-alkylated PACs (method EPA 3540/8270-GC/MS). Sediments deposited in the non-flood prone lake (PAD 18) contained lower concentrations of total PACs compared to sediments deposited during flood-prone periods in the other study lakes, and were dominated by PACs of a pyrogenic rather than bitumen origin. Multivariate analysis of similarity tests identified that the composition of PACs differs between sediments deposited during not flood-prone and flood-prone periods. Subsequent Similarities Percentage (SIMPER) analysis was used and identified seven PACs that are preferentially deposited during flood-prone periods. These seven PACs are bitumen-associated, river-transported and account for 51% of the total PACs found in oil-sands sediment. At PAD 31, which has been flood-prone both before and since onset of Athabasca oil sands development, identified no measureable differences in both the proportion and concentration of the river-transported indicator PACs in sediments deposited pre-1940s versus post-1982. Our findings suggest that natural erosion of exposed bitumen along the banks of the Athabasca River and its tributaries is the main process delivering PACs to the Athabasca Delta, and that the spring freshet is a key period for contaminant mobilization and transport. Such key baseline environmental information is essential for informed management of natural resources and human-health concerns by provincial and federal regulatory agencies and industry, and for designing effective long-term monitoring and surveillance programs for the lower Athabasca River watershed in the face of future oil sands development. Further monitoring activities and additional paleolimnological studies of the depositional history of PACs and other oil-sands- and non-oil-sands-related contaminants is strongly recommended. Overall, results of this research identify that river flooding exerts strong control on physical, chemical and biological conditions of lakes within the PAD. However, contrary to prevailing paradigms, the PAD is not a landscape that has been adversely and permanently affected by regulation of the Peace River and industrial development of the oil sands along the Athabasca River. Instead, data from contemporary and paleolimnological studies identify that natural processes continue to dominate the delivery of water and contaminants to the delta. Regular and frequent flooding is not essential to maintain the supply of nutrients and productivity of delta lakes, which has been a widespread paradigm that developed in the absence of objective scientific data. Instead, nutrient concentrations rise over years to decades after flooding and lake productivity increases. During the thesis research, novel approaches were developed and demonstrated to be effective. Namely, new artificial substrate samplers were designed for aquatic biomonitoring that accrue periphyton and can identify the occurrence of flood events. Also, paleolimnological methods were employed to characterize the composition and concentration of PACs supplied by natural processes prior to oil sands industrial activity, which serves as an important benchmark for assessing industrial impacts. These are effective methods that can be employed to improve monitoring programs and scientific understanding of the factors affecting this world-renowned landscape, as well as floodplains elsewhere.

Os padrões de associação entre epífitos e forófitos não podem ser considerados espécie-específicos, mas as árvores que os epífitos colonizam também não são um conjunto aleatório das espécies forofíticas de um determinado local. Ao invés disso, parece haver uma preferência de certos epífitos por diferentes forófitos. No entanto, se conhece pouco sobre os fatores que determinam essa preferência. Nosso objetivo nesse trabalho é avaliar como os atributos funcionais e a filogenia dos epífitos vasculares influenciam na associação dos epífitos com os forófitos em uma Floresta Ombrófila Mista no sul do Brasil. Para isso nós (1) investigamos padrões de associação positiva e negativa entre grupos funcionais de epífitos e grupos de forófitos e como a diversidade e os atributos funcionais dos epífitos variavam em função do tamanho do forófito e (2) inferimos sobre a existência de sinal filogenético no uso de árvores hospedeiras pelos epífitos, procuramos por estrutura filogenética nas comunidades epifíticas e investigamos diferenças de composição filogenética de epífitos vasculares em diferentes clados de forófitos. Foram amostrados 70 forófitos compreendendo 15 espécies pertencentes a diversos clados e com arquiteturas e características variadas. A amostragem compreendeu 31 espécies epifíticas com os principais clados sendo Polypodiaceae, Bromeliaceae e Orchidaceae. A associação de grupos de epífitos vasculares com diferentes grupos de forófitos sugere que as características dos forófitos proporcionam ambientes contrastantes e que diferentes valores de atributos são necessários para colonizar esses ambientes. Mais especificamente espécies epifíticas com menor área específica foliar (SLA) parecem predominar em árvores maiores e maior SLA em árvores menores. Encontramos sinal filogenético na utilização dos forófitos, sugerindo que a conservação das interações com os forófitos deve ter sido importante ao longo da evolução dos epífitos. A tendência a agrupamento filogenético nas comunidades epifíticas sugere a influência de filtros ambientais representados pelas diferentes características dos forófitos estruturando as assembleias de epífitos. Clados mais basais de forófitos apresentaram composição filogenética distinta devido, sobretudo, a presença de diferentes clados de monilófitos epifíticos nessas árvores. Angiospermas epifíticas ocorreram principalmente em forófitos pertencente as eurosídeas. A preferência de epífitos por forófitos parece ser influenciada pelo surgimento de novidades morfológicas e ecofisiológicas em alguns clados, enquanto outros mantiveram o seu nicho ancestral. A composição florística das florestas quando da origem dos clados epifíticos também parece influenciar a associação entre epífitos e forófitos. Ao utilizar informações sobre os atributos e filogenia das espécies de epífitos vasculares nós podemos melhor compreender os mecanismos ecológicos e históricos que influenciam os padrões de associação entre epífitos e forófitos. / It has been shown that patterns of association between epiphytes and phorophytes can not be considered species-specific, although the trees that epiphytes colonize are not a random subset of phorophyte species in a particular location. Instead, there seems to be a preference of some epiphytes for different phorophytic species. However, little is known about the factors determining this choice. Our objective in this study is to assess how functional attributes and phylogeny of vascular epiphytes influence the association of epiphytes with the phorophytes in an Araucaria Forest in Southern Brazil. For that we (1) investigated the positive and negative association patterns between functional groups of epiphytes and groups of phorophytes and how functional diversity and functional traits of epiphytes varied with host tree size and (2) inferred about the existence of phylogenetic signal on the host trees use by epiphytes, looked for phylogenetic structure in the epiphytic communities and investigated differences in the phylogenetic composition of vascular epiphytes in different phorophyte clades. We used a sample of 70 phorophytes comprising 15 species and belonging to different clades and with different architectures and traits. The sample comprised 31 epiphytic species, the major clades being Polypodiaceae, Bromeliaceae and Orchidaceae. The combination of vascular epiphyte groups with different groups of 15 phorophytes suggests that phorophyte traits provide contrasting environments and that different trait values are needed to colonize these environments. More specifically, epiphytic species with lower specific leaf area (SLA) seem to predominate on larger trees and with higher SLA values on smaller trees. We found phylogenetic signal on the host tree use, suggesting that conservatism of the interactions with phorophytes must have been important throughout the evolution of epiphytes. The tendency to phylogenetic clustering in the epiphytic communities suggests the influence of environmental filters represented by phorophyte traits structuring epiphyte assemblages. More basal clades of phorophytes showed different phylogenetic composition mainly due to the presence of different epiphytic monilophyte clades on these trees. Epiphytic angiosperms occurred mainly on those trees belonging to eurosids. The preference of epiphytes for phorophytes seems to be influenced by morphological and ecophysiological novelties in some lineages, while other clades kept their ancestral niche. The floristic composition of forests at the origins of epiphytic lineages also appears to influence the association between epiphytes and phorophytes. By using information about the traits and phylogeny of species of vascular epiphytes we can better understand the ecological and historical mechanisms that influence the patterns of association between epiphytes and phorophytes.

Os padrões de associação entre epífitos e forófitos não podem ser considerados espécie-específicos, mas as árvores que os epífitos colonizam também não são um conjunto aleatório das espécies forofíticas de um determinado local. Ao invés disso, parece haver uma preferência de certos epífitos por diferentes forófitos. No entanto, se conhece pouco sobre os fatores que determinam essa preferência. Nosso objetivo nesse trabalho é avaliar como os atributos funcionais e a filogenia dos epífitos vasculares influenciam na associação dos epífitos com os forófitos em uma Floresta Ombrófila Mista no sul do Brasil. Para isso nós (1) investigamos padrões de associação positiva e negativa entre grupos funcionais de epífitos e grupos de forófitos e como a diversidade e os atributos funcionais dos epífitos variavam em função do tamanho do forófito e (2) inferimos sobre a existência de sinal filogenético no uso de árvores hospedeiras pelos epífitos, procuramos por estrutura filogenética nas comunidades epifíticas e investigamos diferenças de composição filogenética de epífitos vasculares em diferentes clados de forófitos. Foram amostrados 70 forófitos compreendendo 15 espécies pertencentes a diversos clados e com arquiteturas e características variadas. A amostragem compreendeu 31 espécies epifíticas com os principais clados sendo Polypodiaceae, Bromeliaceae e Orchidaceae. A associação de grupos de epífitos vasculares com diferentes grupos de forófitos sugere que as características dos forófitos proporcionam ambientes contrastantes e que diferentes valores de atributos são necessários para colonizar esses ambientes. Mais especificamente espécies epifíticas com menor área específica foliar (SLA) parecem predominar em árvores maiores e maior SLA em árvores menores. Encontramos sinal filogenético na utilização dos forófitos, sugerindo que a conservação das interações com os forófitos deve ter sido importante ao longo da evolução dos epífitos. A tendência a agrupamento filogenético nas comunidades epifíticas sugere a influência de filtros ambientais representados pelas diferentes características dos forófitos estruturando as assembleias de epífitos. Clados mais basais de forófitos apresentaram composição filogenética distinta devido, sobretudo, a presença de diferentes clados de monilófitos epifíticos nessas árvores. Angiospermas epifíticas ocorreram principalmente em forófitos pertencente as eurosídeas. A preferência de epífitos por forófitos parece ser influenciada pelo surgimento de novidades morfológicas e ecofisiológicas em alguns clados, enquanto outros mantiveram o seu nicho ancestral. A composição florística das florestas quando da origem dos clados epifíticos também parece influenciar a associação entre epífitos e forófitos. Ao utilizar informações sobre os atributos e filogenia das espécies de epífitos vasculares nós podemos melhor compreender os mecanismos ecológicos e históricos que influenciam os padrões de associação entre epífitos e forófitos. / It has been shown that patterns of association between epiphytes and phorophytes can not be considered species-specific, although the trees that epiphytes colonize are not a random subset of phorophyte species in a particular location. Instead, there seems to be a preference of some epiphytes for different phorophytic species. However, little is known about the factors determining this choice. Our objective in this study is to assess how functional attributes and phylogeny of vascular epiphytes influence the association of epiphytes with the phorophytes in an Araucaria Forest in Southern Brazil. For that we (1) investigated the positive and negative association patterns between functional groups of epiphytes and groups of phorophytes and how functional diversity and functional traits of epiphytes varied with host tree size and (2) inferred about the existence of phylogenetic signal on the host trees use by epiphytes, looked for phylogenetic structure in the epiphytic communities and investigated differences in the phylogenetic composition of vascular epiphytes in different phorophyte clades. We used a sample of 70 phorophytes comprising 15 species and belonging to different clades and with different architectures and traits. The sample comprised 31 epiphytic species, the major clades being Polypodiaceae, Bromeliaceae and Orchidaceae. The combination of vascular epiphyte groups with different groups of 15 phorophytes suggests that phorophyte traits provide contrasting environments and that different trait values are needed to colonize these environments. More specifically, epiphytic species with lower specific leaf area (SLA) seem to predominate on larger trees and with higher SLA values on smaller trees. We found phylogenetic signal on the host tree use, suggesting that conservatism of the interactions with phorophytes must have been important throughout the evolution of epiphytes. The tendency to phylogenetic clustering in the epiphytic communities suggests the influence of environmental filters represented by phorophyte traits structuring epiphyte assemblages. More basal clades of phorophytes showed different phylogenetic composition mainly due to the presence of different epiphytic monilophyte clades on these trees. Epiphytic angiosperms occurred mainly on those trees belonging to eurosids. The preference of epiphytes for phorophytes seems to be influenced by morphological and ecophysiological novelties in some lineages, while other clades kept their ancestral niche. The floristic composition of forests at the origins of epiphytic lineages also appears to influence the association between epiphytes and phorophytes. By using information about the traits and phylogeny of species of vascular epiphytes we can better understand the ecological and historical mechanisms that influence the patterns of association between epiphytes and phorophytes.

Made available in DSpace on 2014-06-11T19:23:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-19Bitstream added on 2014-06-13T19:28:53Z : No. of bitstreams: 1 almeida_ojg_me_rcla.pdf: 2506622 bytes, checksum: 9d9c114a31bacd63b72f96f10218d1e2 (MD5) / Cactaceae distribui-se pelo continente americano, do sul e oeste do Canadá até o sul da Patagônia na Argentina e Chile. A família está inserida em Caryophyllales e possui cerca de 1.500 espécies. Epiphyllum phyllanthus (L.) Haw. é epífita obrigatória muito difundida na América do Sul, sendo a única espécie brasileira nativa de Epiphyllum Haw. A biologia reprodutiva em Cactaceae foi estudada em menos de 10% das espécies que a constituem e, esta limitada quantidade de dados, impede melhor entendimento dos mecanismos reprodutivos na família. Objetivou-se a realização de estudo morfológico e anatômico dos órgãos reprodutivos e da plântula de E. phyllanthus, através de: (i) análise morfoanatômica da flor; (ii) morfoanatomia e ontogenia do pericarpo e da semente e (iii) morfoanatomia da plântula. A flor é séssil, epígina com hipanto desenvolvido. Todos os verticilos florais apresentam epiderme unisseriada, glabra e estomatífera. O gineceu é sincárpico, com 9-10 carpelos, pluriovulado, de placentação parietal. O ovário possui feixes vasculares invertidos. A flor apresenta região nectarífera na face interna do hipanto. O óvulo é circinótropo, bitegumentado, crassinucelado, de funículo longo. O hipanto é de natureza receptacular. O fruto é do tipo cactídio de coloração róseo-roxo brilhante, superfície lisa e acumula concentração elevada de amido no pericarpo e na polpa, quando maduro. As sementes são campilótropas, pretas e de formato ovóide. A superfície externa ventral exibe relevo diferenciado, a região hilo-micropilar, de coloração esbranquiçada, onde ocorre arilo. O embrião é curvo com reserva lipoprotéica. Perisperma e endosperma persistem na semente madura, sem substâncias de reserva. A plântula é fanerocotiledonar e apresenta germinação epígea. Durante a germinação há hidratação e expansão de mucilagem na semente... / The Cactaceae family is widely distributed in the American continents, from the south and west of Canada to the south of Patagonia (Argentina and Chile). It is included in Caryophyllales and has approximately 1,500 species. Epiphyllum phyllanthus (L.) Haw. exhibits an obligatory epiphytic habit and is widespread in South America. Additionally, it is the only Epiphyllum Haw. species that is indigenous to Brazil. Studies concerning the reproductive biology of Cactaceae have been conducted in no more than 10 percent of the taxa, and such a limited amount of data precludes the suitable comprehension of the reproductive mechanisms in the family. The present work was aimed at providing a morphoanatomical description of the reproductive organs and seedlings of Epiphyllum phyllanthus by means of (i) flower morphoanatomical analysis; (ii) morphoanatomical and ontogenic studies of the pericarp and seed, and (iii) morphoanatomical analysis of seedling in developing. It was observed that the sessile and epigynous flower exhibit a well-developed hypanthium. All the flower whorls has uniseriate epidermis. The syncarpous and pluriovulate gynoecium exhibit 9-10 carpels and parietal placentation. The ovary has inverted bundles and the flower showed the nectariferous region on the inner surface of the hypanthium. The ovule is circinotropous, bitegmic, crassinucelate, and has a long funiculus. The hypanthium exhibit receptacular origin. The bright pinkish-purplish “cactidio-type” fruit has a smooth surface and, when it is ripe, exhibits a high concentration of starch in the pericarp and pulp. The seed is campylotropous, black and ovoid. Its ventral outer surface presents a differentiated relief that is the whitish hilum-micropylar region, in which the aril occurs. The curved embryo contains lipoprotein reserves. Perisperm and endosperm persist in the mature seed without reserve substances... (Complete abstract click electronic access below)

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