Made available in DSpace on 2014-07-29T16:22:04Z (GMT). No. of bitstreams: 1 Dissertacao Carla Patricia P Alves.pdf: 1914575 bytes, checksum: 1e548e27bdfb0a8d68e317095b54fcc7 (MD5) Previous issue date: 2011-03-28 / The river-floodplain systems are environments submitted a lateral overflow of river channel due the rains and/or underground waters. They are controlled by the type of climate, morphology and local effects. The lowland lakes are also highly productive because of the rich sources of primary carbon. The sediments transport and suspended and dissolved matter are done by the rivers between the land and aquatic phases. These phases strongly influence nutrient cycling, primary and secondary production and decomposition. The phytoplankton dynamics in tropical floodplain lakes is as variable as the seasonal and isolation patterns of flooding. For this reason, the aims of this work were i) to assess the rotation influence of potamophase and limnophase upon the phytoplankton of the Curuai Lake (PA, Brazil) and about the connectivity between other lakes, and ii) to evaluate the phytoplankton dynamics in a nictemeral cycling related to changes in CO2 in water, and what phytoplankton groups which were most important in this process. The phytoplankton community and environmental variables of the floodplain lakes of the Curuai Lake were sampled in the potamophase and limnophase (2009) and in a nictemeral cycling (2010). The informations summarized were obtained through the principal component analysis (PCA), canonical correspondence analysis (CCA), redundancy analysis (RDA) and nonmetric multidimensional scaling (MDS). The community structure was different among the periods with greater richness, density and phytoplanktonic biovolume in limnophase. There was predominance of Cryptophyceae (mainly Cryptomonas brasiliensis Castro, Bicudo & Bicudo) in potamophase and Cyanophyceae [Dolichospermum circinalis (formerly Anabaena circinalis) (Rabenh. ex Bornet et Flah.) Wacklin et al.] in limnophase, both influenced by environmental variables. In addition, the high phytoplanktonic biomass was favored by the highs temperatures and also responsible by the CO2 depletion in water caused by photosynthesis, which is reflected for the high carbon content in phytoplankton organisms. Despite the entry of water in the floodplain that connects the lakes, these environmental were distinct in relation a phytoplankton composition and a limnological variables. The phytoplanktonic community in Curuai Lake showed daily variation of biovolume because of high temperature and light availability. The development of persistent cyanobacteria bloom, with species predominance of Dolichospermum genius [functional group H1, D. spiroides (formerly A. spiroides) (Klebahn) Wacklin et al.] and Microcystis protocystis Crow (functional group M) caused the CO2 depletion in lake surface layer during the period of increased photosynthesis. The cyanobacteria bloom occurred mainly due to the attributes of group, which became it expressive competitors in relation another microalgae ones. / Os sistemas rio-planície de inundação são ambientes sujeitos ao transbordamento lateral do canal do rio pelas chuvas e ou águas subterrâneas e são controlados pelo tipo de clima, morfologia e efeitos locais. Esses ambientes são também altamente produtivos por causa das ricas fontes de carbono primário. O transporte de sedimentos e matéria suspensa e dissolvida é feito pelos rios entre as fases terrestre e aquática, influenciando fortemente o ciclo de nutrientes, produção primária, secundária e decomposição. A dinâmica do fitoplâncton em lagos de planícies de inundação tropicais é tão variável quanto os padrões sazonais de alagamento e isolamento. Por esta razão, os objetivos deste trabalho foram: i) verificar a influência da alternância da potamofase e limnofase sobre o fitoplâncton do Lago Grande de Curuai (PA) e sobre a conectividade entre os lagos e ii) avaliar a dinâmica do fitoplâncton em um ciclo nictimeral relacionada às mudanças do CO2 na água, bem como quais grupos fitoplanctônicos desempenharam maior importância nesse processo. Para isto, a comunidade fitoplanctônica e variáveis ambientais dos lagos da várzea do Lago Grande de Curuai foram amostrados na potamofase e limnofase (2009) e num ciclo nictimeral (2010). A síntese das informações foram obtidas através de análise de componentes principais, análise de correspondência canônica, análise de redundância e escalonamento multidimensional não-métrico. A estrutura da comunidade foi distinta entre os períodos com maiores riqueza, densidade e biovolume fitoplanctônico na limnofase. Houve predomínio de Cryptophyceae (principalmente Cryptomonas brasiliensis Castro, Bicudo & Bicudo) na potamofase e Cyanophyceae [Dolichospermum circinalis (antes Anabaena circinalis) (Rabenh. ex Bornet et Flah.) Wacklin et al.] na limnofase, influenciadas pelas condições ambientais. Além disso, a alta biomassa fitoplanctônica foi favorecida pelas altas temperaturas e também responsável pela diminuição do CO2 na água pela fotossíntese, refletida pelo alto conteúdo de carbono no fitoplâncton. Apesar da entrada de água na várzea que conecta os lagos, os ambientes foram distintos quanto à composição do fitoplâncton e às variáveis limnológicas. A comunidade fitoplanctônica no Lago Grande de Curuai apresentou variação diária do biovolume propiciadas pela alta temperatura e disponibilidade de luz. O desenvolvimento de floração persistente de cianobactérias, com predomínio de espécies do gênero Dolichospermum [grupo funcional H1, destaque D. spiroides (antes A. spiroides) (Klebahn) Wacklin et al..) e de Microcystis protocystis Crow (grupo funcional M) causou a depleção de CO2 na camada superficial do lago durante o período de maior fotossíntese. A floração de cianobactérias ocorreu principalmente devido aos atributos desse grupo que o tornam competidores expressivos em relação aos demais grupos de microalgas.

Ce travail de thèse est consacré à la préparation de glycopolymères porteurs de groupements pendants mannoside d’heptyle et à l’évaluation de la capacité de ces ligands multivalents à inhiber la fixation bactérienne sur les cellules humaines. Nous avons synthétisé, par polymérisation radicalaire contrôlée, une série de glycopolymères linéaires ou en étoile présentant des masses molaires, des densités en mannoside et des microstructures modulables dans le but d’évaluer l’influence de ces paramètres sur les processus d’interactions avec diverses souches de bactéries E coli (AIEC LF82 et UTI 89). Nous avons tout d’abord mis en évidence par diffusion dynamique et statique de la lumière, la formation d’agrégats entre ces glycopolymères et FimH, la lectine à l’origine de la fixation de souches de bactéries E coli, traduisant des interactions fortes entre les motifs mannosides et les sites de reconnaissance au mannose de la lectine. Nous avons ensuite évalué l’aptitude de ces ligands multivalents à bloquer l’adhésion bactérienne d’AIEC LF82 (impliquée dans la maladie de Crohn) sur des cellules épithéliales intestinales T84. Il a été démontré en conditions in vitro que l’ajout de 10 nM ou 100 nM d’unités mannoside (respectivement en pré- ou post-incubation) réduit de moitié l’adhésion des bactéries sur les cellules épithéliales. L’effet anti-adhésif de ces glycopolymères a été confirmé par des tests ex vivo réalisés sur des intestins isolés de souris transgéniques CEABAC10. Enfin, nous avons exploité la technique de nanoprécipitation pour l’élaboration de nanocapsules de glycopolymères à cœur huileux. Le procédé développé permet la synthèse de nanocapsules de dimensions contrôlées, porteuses de groupements fonctionnels (fluorophores, ligands) ou de particules métalliques et l’encapsulation de molécules actives à cœur en une seule étape. / This PhD work focuses on the preparation of glycopolymers bearing pendent heptyl mannose groups and the evaluation of the capability of such multivalent ligands to inhibit bacterial adhesion to human cells. Aiming at understanding the impact of various structural parameters on glycopolymer/ E coli interactions (AIEC LF82 et UTI 89 strains of E. coli), a series of linear and star-shaped glycopolymers with tunable molecular weight, mannoside density and microstructure (block copolymers, gradient copolymers, random copolymers) has been constructed. The association of the glycopolymers with FimH adhesin, a lectin which possesses a mannose-specific receptor site and is responsible for recognition and binding to host cells, was first confirmed by static and dynamic light scattering experiments. The propensity of the glycopolymers to prevent attachment of E. coli (AIEC LF82 involved in Crohn’s disease) to intestinal epithelial cells (T84 cells) was further investigated through adhesion assays. It was shown that under in vitro conditions, the addition of 10 nM or 100 nM of glycopolymer on a mannose unit basis (in pre-incubation and post-incubation respectively) decreases by half the bacterial adhesion to intestinal epithelial cells. The anti-adhesive effect of these multivalent ligands was further confirmed in ex vivo conditions for colonic loops of transgenic CEABAC10 mice (Crohn’s disease model mouse). Finally we took advantage of the nanoprecipitation process to generate glyconanocapsules with oily core. The employed strategy allowed for preparing well-defined nanocapsules bearing groups of interest (tags, ligands) or metal particles within the shell and loaded with active molecules in the core in one step.

In dieser Arbeit sollte eine Derivatisierungsmethode entwickelt werden, die die duale Quantifizierung funktioneller Gruppen an Oberflächen mittels Röntgenphotoelektronenspektroskopie (XPS) und Fluoreszenz ermöglicht. Verschiedene Farbstoffe, die robuste Fluoreszenzeigenschaften mit hohen Fluorgehalten für XPS kombinieren, wurden auf ihre selektive Reaktion mit Aminogruppen getestet und der Prototyp einer tiefergehenden Analyse auf einer Oberfläche unterzogen. Durch Fluoreszenzlöschung konnten die Möglichkeiten der bimodalen Analyse nur begrenzt abgeschätzt werden, obwohl in XPS und Fluoreszenz intensive Signale gemessen wurden. Die Herstellung der Modelloberflächen mittels Gasphasenabscheidung von Silanen konnte durch Kontaktwinkelmessungen schrittweise optimiert werden. Die Kombination zweier Monoalkoxysilane ermöglichte die Herstellung von Oberflächen mit variabler Funktionalgruppendichte. Nach Reaktion mit dem dualen Marker ließen sich die Messungen aus XPS und Fluoreszenz mindestens über eine Größenordnung korrelieren. Durch Synchrotron-XPS (SR-XPS) und Röntgenfluoreszenz unter Totalreflektion (TXRF) konnte eine absolute und rückführbare Quantifizierung erzielt werden. Weitere Modelloberflächen auf Basis von Trialkoxysilanen zeigten, dass bei anwendungsnahen Proben Fluoreszenzlöschung auftritt. Diese konnte in einem gewissen Maße mittels Fluoreszenzlebensdauer berechnet werden. Darüberhinaus konnte mit der Photometrie eine unabhängige Methode gefunden werden, die die Quantifizierung des Farbstoffs an der Oberfläche in hoher Präzision ermöglicht und mit Hilfe der XPS auch der funtionellen Gruppen. Die Cavity Ring-Down Spektroskopie (CRDS) wurde als Laserbasierte Methode zur empfindlichen und ortsaufgelösten Messung der Absorption auf transparenten Substraten untersucht und erste vielversprechende Ergebnisse gewonnen. Weiterhin wurde ein modulares Farbstoffsystem entwickelt, das sowohl Variation der spektralen als auch der Bindungseigenschaften erlaubt. / This work aimed on the development of dual-mode labelling method that combines X-ray photoelectron spectroscopy (XPS) with fluorescence measurements for surface functional group quantification. Label dyes combining robust fluorescence properties with high fluorine contents were investigated towards their selective reaction with surface amino groups and the lead candidate subjected to detailed analysis on a surface. Fluorescence quenching precluded a detailed investigation of the capabilities of dual-mode labelling, despite providing sufficient signal in XPS and fluorescence scanning. The fabrication of surfaces using vapour deposition (VD) of silanes in toluene was optimized under aid of contact angle measurements. Binary mixtures of mono-alkoxy silanes were used to prepare surfaces with variable functional group density. Treatment with the label dye showed that XPS and fluorescence provide a linear overlap in signal generation over at least one order of magnitude. The combination of synchrotron radiation XPS (SR-XPS) and total reflection X-ray fluorescence spectroscopy (TXRF) provided an absolute and traceable quantification . Different model surfaces based on trialkoxy silanes showed strong fluorescence quenching. A fluorescence lifetime based correction was developed to account for such quenching effects. Additionally, the application of spectrophotometry provided a independent method of quantification for the surface bound dye and in combination with information obtained from XPS, to determine the surface functional group density. With cavity ring-down spectroscopy (CRDS), a laser based technique for highly sensitive and spatially resolved absorption measurements on transparent substrates could be developed and applied in a proof-of-concept. A modular system for the fabrication of label dyes with adjustable spectral properties and different binding sites was investigated using prototype candidates to prove the general applicability of such systems.

<p>Effects of prairie restoration on arthropod diversity was investigated at Gabis Arboretum, Valparaiso, Indiana. A total of 35,408 arthropods belonging to 13 taxa in the restored prairie (RP1 and RP2), old field (OF), and monoculture stand of Phalaris arundinacea (reed canary grass – RCG) sites, were captured, counted, and compared. The enhanced plant species diversity in the restored prairies did not appear to promote the diversity of arthropod taxa. However, the restoration led to a more balanced composition of arthropod functional groups and thus elevated the diversity of functional groups. The arthropod assemblages in the three sites diverged clearly according to my canonical correspondence analysis (CCA) ordination. Pollinator abundance was greatest at RP and least at RCG site, positively correlating with greater forb diversity, and suggesting greater potential for nectar feeding and pollination potential at RP sites. Herbivore abundance was greatest at the RP sites, positively correlating with increasing plant species diversity. Predator abundance was significantly greater at the RCG site compared to the OF and RP sites; it was positively correlated with greater C3 grass cover, a characteristic of the structurally homogenous RCG site, and negatively correlated with increasing plant diversity and forb cover, a characteristic of the diverse and more structurally complex RP sites. Given the apparent non-random distribution of arthropods among the field types, my results suggest plant species composition has a significant effect on arthropod assembly. The monoculture grass stand was found to have a predator dominated arthropod community supported by a small, diverse herbivore community. It is concluded that the prairie restoration has resulted in alteration of arthropod communities supporting greater pollinator and herbivore abundance and a more balanced ratio of herbivores to predators due, in part, to increased plant structural diversity.</p>

<p>Chromatography is a powerful technique, essential in chemical analyses and preparative separation in industry and research. Many different kinds of chromatographic material are needed, due to the large variety of applications. Detailed methods of characterisation are needed to design new chromatographic materials and understand their properties. In this thesis, confocal Raman spectroscopy and surface enhanced Raman spectroscopy (SERS) have been applied to micrometer-size chromatographic beads, for which these techniques have not been used earlier. New methodology, optimized for use with the chromatographic beads, has been developed and evaluated. </p><p>Confocal spectroscopy has been used to determine distributions of functional groups within single chromatographic beads. This distribution is of great importance in determining the chromatographic properties, since the material is porous and the solute molecules can diffuse inside the beads. Most of the confocal experiments have been performed with Raman spectroscopy; fluorescence spectroscopy, using Nd³⁺ ions or dye-labelled proteins as fluorescence probes, has been used for comparison. </p><p>The concentration of adsorbed analytes is very low within the beads. SERS was therefore used to enhance the Raman signal. SERS-active surfaces were prepared by incorporating gold nano-particles into the interior of the bead. TEM measurements showed that the gold nano-particles could be observed throughout, and it was possible to record analyte spectra from different positions within the bead. Enhanced spectra could be obtained both for small test molecules and for larger bio-molecules, although the spectra for the smaller analytes were much more intense.</p>

Chromatography is a powerful technique, essential in chemical analyses and preparative separation in industry and research. Many different kinds of chromatographic material are needed, due to the large variety of applications. Detailed methods of characterisation are needed to design new chromatographic materials and understand their properties. In this thesis, confocal Raman spectroscopy and surface enhanced Raman spectroscopy (SERS) have been applied to micrometer-size chromatographic beads, for which these techniques have not been used earlier. New methodology, optimized for use with the chromatographic beads, has been developed and evaluated. Confocal spectroscopy has been used to determine distributions of functional groups within single chromatographic beads. This distribution is of great importance in determining the chromatographic properties, since the material is porous and the solute molecules can diffuse inside the beads. Most of the confocal experiments have been performed with Raman spectroscopy; fluorescence spectroscopy, using Nd3+ ions or dye-labelled proteins as fluorescence probes, has been used for comparison. The concentration of adsorbed analytes is very low within the beads. SERS was therefore used to enhance the Raman signal. SERS-active surfaces were prepared by incorporating gold nano-particles into the interior of the bead. TEM measurements showed that the gold nano-particles could be observed throughout, and it was possible to record analyte spectra from different positions within the bead. Enhanced spectra could be obtained both for small test molecules and for larger bio-molecules, although the spectra for the smaller analytes were much more intense.

No description available.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-01-20T23:17:07Z No. of bitstreams: 1 Ana Paula Lima do Cout1.pdf: 2447904 bytes, checksum: 7c9755ccd95ffbece7c6941079071845 (MD5) / Made available in DSpace on 2016-01-20T23:17:07Z (GMT). No. of bitstreams: 1 Ana Paula Lima do Cout1.pdf: 2447904 bytes, checksum: 7c9755ccd95ffbece7c6941079071845 (MD5) Previous issue date: 2014-09-30 / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB / (Effect of edge in structure, diversity and phenology in seasonal tropical forest submontane) Forest fragmentation causes physical and biological changes with habitat loss and insularization of populations, and the edge effect the most obvious consequence of this process. Thus, this study aimed to investigate the effect of linear edge in a fragment of submontane seasonal forest in the Chapada Diamantina, Bahia, Brazil (12?28'31 "S and 41?23'14''W) in order to analyze the structure and composition vegetation, reproductive phenology and the vegetative phenology, classifying the forest as their leaf pattern, and the functional diversity. Were marked 30 plots (10 x 10 m) random and 15 at the forest edge (0 - 100m) and 15 inside (> 150m) in the power line high voltage. For structural studies were marked all individuals with diameter at breast height ?5 cm. The species were classified according to successional category and phytosociological parameters were calculated and diversity indices. The Shannon - Wiener index was compared by t test Hutcheson and the other parameters by ANOVA. From this study the species with the highest importance value and abundance for the other investigations were chosen. In the reproductive phenological study monthly observations were made over 26 months in 481 individuals (282 on the edge (61 species) and 199 inside (50 species) of forest), recording the presence and absence of flowering (and flower button) and fruiting (immature and mature fruit) for all life forms. It is estimated timing, frequency and duration of phenological events and the species were classified as the pollination and dispersal syndromes. Data were analyzed with G test, linear regression and circular statistics. In the study of functional diversity created a matrix of functional traits to the edge and interior including phenological, structural and reproductive aspects. Measurements of leaf traits (thickness, dry dough sheet per unit area, juiciness, density, leaf area ratio and leaf mass fraction), density and wood water saturation were carried out in the dry and wet seasons (September / 2012 and January / 2013) in 20 species. Regressions were made between phenophases and environmental variables (precipitation, temperature, relative humidity, photoperiod and heat stroke), circular statistics and comparisons of leaf traits and wood density between the dry and rainy season through the G test and ANOVA. The species ordination in relation to leaf and wood attributes was evaluated by Principal Component Analysis (PCA). The functional groups were defined by cluster analysis with distance Gower and calculated indexes Functional richness (FRic), Functional divergence (FDiv), Functional evenness (FEve), Functional dispersion (FDis). ANOVA and linear regression were used to evaluate the rates between areas. In vegetative phenological study followed up the budding and leaf fall 350 individual trees in the community (39 species). Increase the impact of straight edge on the floristic composition was checked, the diversity and abundance of species, while less interference was observed in the tree community structure, as phytosociological parameters and ratios between the guilds did not differ significantly between edge and interior fragment. The phenological analysis revealed that flowering and fruiting at the edge and interior were continued for long, low-intensity periods, asynchronous and assazonal being for most phenophases, with a significant difference in the individual to button number. Seasonality in flowering and fruiting were observed for bush and grass land in both areas and epiphytes to the edge. Similar proportions in the number of species for pollination and dispersal syndromes were found on the edge and inside, with a predominance of melittophilous and animal dispersed species. The vegetation was evergreen, with budding and continuous leaf fall, low intensity and low sync. The leaf bud was related to rainfall and sunshine and fall with precipitation and humidity. Significant variation between the dry and wet seasons were observed in the proportion of saturated water in the wood, leaf area ratio and leaf succulence. ACP showed greater variance for wood density (88.7%) and stored water (11.3%), gathering most species with standard perenif?lios phenological and episodic perenif?lios, other attributes showed no relevance to the phenological patterns. The main functional groups formed on the edge and inside were similar, defined based on the way of life, stratum and pollination and dispersal. Of co-occurring species (40 species), 22.5% belong to different functional groups due to different growth patterns. The functional diversity indices showed higher mean values for the edge, except that Fric was higher in the forest. These were not affected by the distance to the edge. Changes were observed inside in relation to species richness and Shannon - Wiener only for Fric. The implementation of linear infrastructure brings similar impacts to those coming from other types of edges in community structure. In other aspects analyzed the changes were subtle for the tree community, but the same was not true for shrubs, herbs and vines. The vegetation can be classified as seasonal submontane rainforest always green, with small annual variation in the physiognomy of the vegetation, and the perenif?lios and perenif?lios types episodic predominant both in number of species and in their abundance. The leaf traits showed no relevance to phenology, not being good descriptors for the seasonal evergreen forest. There is no significant difference in functional diversity, but the highest rate obtained inside for functional wealth reflects the biological loss caused by the installation on the edge of the linear edge. Appearance evidenced by the greater abundance of Eschweilera tetrapetala Mori inside, an endemic species of submontane forests of the region. This study contributes to future conservation work to note the interference the linear edge on the forest ecosystem, as well as to the classification of the Brazilian forests, to verify the occurrence of seasonal evergreen forests in the Caatinga. / (Efeito de borda na estrutura, diversidade e fenologia de floresta tropical estacional submontana) A fragmenta??o florestal causa mudan?as f?sicas e biol?gicas com perda de habitat e insulariza??o das popula??es, sendo oefeito de borda a consequ?ncia mais evidente desse processo.Assim,objetivou-se investigar o efeito da borda linear em um fragmento de floresta estacional submontana na Chapada Diamantina, Bahia,Brasil (12?28?31??S e 41?23?14??W) com o intuito de analisar a estruturae a composi??o da vegeta??o, a fenologia reprodutivae a fenologia vegetativa, classificando a floresta quanto ao seu padr?o foliar, e a diversidade funcional. Foram marcadas 30 parcelas (10 x 10 m) aleat?rias sendo 15 na borda da floresta (0 - 100m) e 15 no seu interior (>150m) em rela??o ? rede el?trica de alta tens?o. Para o estudo estrutural foram marcados todos os indiv?duos com di?metro ? altura do peito ?5 cm. As esp?cies foram classificadas quanto ? categoria sucessional e foram calculados os par?metros fitossociol?gicos e ?ndices de diversidade. O ?ndice de Shannon - Wienerfoi comparado pelo teste t de Hutcheson e os demais par?metros pela ANOVA. A partir desse estudo foram escolhidas as esp?cies com maior valor de import?ncia e abundancia para as demais investiga??es.No estudo fenol?gico reprodutivo foram realizadas observa??es mensais durante 26 meses a 481 indiv?duos (282 na borda (61 esp?cies) e 199 no interior (50 esp?cies) da floresta), registrando-se a presen?a e aus?ncia de flora??o (bot?o e flor) e frutifica??o (frutos imaturo e maturo) para todas as formas de vida. Estimou-se sincronia, frequ?ncia e dura??o dos eventos fenol?gicos e as esp?cies foram classificadas quanto ?s s?ndromes de poliniza??o e dispers?o. Os dados foram analisados com teste G, regress?o linear e estat?stica circular. No estudo da diversidade funcional criou-se uma matriz de tra?os funcionais para a borda e interior incluindo aspectos fenol?gicos, estruturais e reprodutivos.Mensura??es de atributos foliares (espessura, massa seca de folha por unidade de ?rea, sucul?ncia, densidade, raz?o de ?rea foliar e fra??o de massa foliar), densidade e ?gua de satura??o da madeira foram realizadas nas esta??es seca e chuvosa (setembro/2012 e janeiro/2013) em 20 esp?cies. Foram feitas regress?es entre as fenofases e as vari?veis ambientais (precipita??o, temperatura, umidade relativa, fotoper?odo e insola??o), estat?stica circular e compara??es dos atributos foliares e densidade de madeira entre a esta??o seca e chuvosa atrav?s do teste G e ANOVA. A ordena??o das esp?cies em rela??o aos atributos foliares e de madeira foi avaliada pela An?lise do Componente Principal (ACP). Os grupos funcionais foram definidos por Cluster analysis com dist?ncia de Gower e calculados os ?ndices Functional richness (FRic), Functional divergence (FDiv), Functional evenness (FEve), Functional dispersion (FDis). ANOVA e regress?o linear foram usadas para avaliar os ?ndices entre ?reas. No estudo fenol?gico vegetativo acompanhou-se o brotamento e queda foliar de 350 indiv?duos arb?reos na comunidade (39 esp?cies). Foi verificado um maior impacto da borda linear sobre a composi??o flor?stica,a diversidade e abund?ncia das esp?cies, enquanto menor interfer?ncia foi verificada na estrutura da comunidade arb?rea, uma vez que par?metros fitossociol?gicos e propor??es entre as categorias sucessionais n?o diferiram significativamente entre borda e interior do fragmento.As an?lises fenol?gicas revelaram que a flora??o e frutifica??o na borda e interior foram cont?nuas por per?odos longos e com baixa intensidade, sendo assincr?nico e assazonal para a maioria das fenofases, com diferen?a significativa no n?mero de indiv?duo para bot?o.Sazonalidade na flora??o e frutifica??o foi observada para arbusto e erva terrestre em ambas as ?reas e ep?fitas para a borda.Propor??es semelhantes no n?mero de esp?cies por s?ndromes de poliniza??o e dispers?o foram encontradas na borda e no interior, com predomin?ncia de esp?cies melit?filas e zooc?ricas.A vegeta??o foi perenif?lia, com brotamento e queda foliar cont?nuos, baixa intensidade e baixa sincronia. O brotamento foliar relacionou-se com precipita??o e insola??o e a queda com precipita??o e umidade. Varia??o significativa entre as esta??es seca e chuvosa foram observadas na propor??o de ?gua saturada na madeira, raz?o de ?rea foliar e sucul?ncia da folha. ACP revelou maior varian?a para densidade da madeira (88,7%) e ?gua armazenada (11,3%), agrupando a maioria das esp?cies com padr?o fenol?gico perenif?lios e perenif?lios epis?dicos, os demais atributos n?o apresentaram relev?ncia em rela??o aos padr?es fenol?gicos. Os principais grupos funcionais formados na borda e no interior foram semelhantes, definidos com base na forma de vida, estrato e s?ndrome de poliniza??o e dispers?o. Das esp?cies co-ocorrentes (40 esp?cies), 22,5% pertencem a grupos funcionais distintos devido a diferentes padr?es fenol?gicos. Os ?ndices de diversidade funcional apresentaram valores m?dios superiores para a borda, exceto FRic que foi superior no interior da floresta. Estes n?o foram alterados pela dist?ncia com a borda. Altera??es foram observadas no interior em rela??o ? riqueza de esp?cie e ao ?ndice de Shannon - Wiener apenas para FRic.A implementa??o de infraestruturas lineares traz impactos semelhantes ?queles advindos de outros tipos de bordas na estrutura da comunidade. Nos demais aspectos analisados as varia??es foram sutis para a comunidade arb?rea, mas o mesmo n?o ocorreuem rela??o a arbustos, ervas e trepadeiras. A vegeta??o p?de ser classificada como floresta tropical estacional submontana sempre verde, com pequena varia??o anual na fisionomia da vegeta??o, sendo os tipos perenif?lios e perenif?lios epis?dicos predominantes tanto em n?mero de esp?cies quanto na sua abund?ncia. Os atributos foliares n?o apresentaram relev?ncia em rela??o aos padr?es fenol?gicos, n?o sendo bons descritores para a floresta estacional sempre verde. N?o h? diferen?a significativa na diversidade funcional, mas o maior ?ndice obtido no interior para a riqueza funcional reflete a perda biol?gica ocasionada na borda pela instala??o da borda linear.Aspecto evidenciado pela maior abund?ncia deEschweilera tetrapetala Mori no interior, esp?cie end?mica das florestas submontanas da regi?o. O presente estudo p?de contribuir com futuros trabalhos de conserva??o por constatar a interfer?ncia da borda linear no ecossistema florestal, bem como com a classifica??o das florestas brasileiras, ao verificar a ocorr?ncia de florestas estacional sempre verde no Bioma Caatinga.

Crop rotation may be used to prevent the continuous selection of particular weed species adapted to one crop type. This might be useful for weed management, economy in herbicide applications and promoting biodiversity. Common simple crop sequences might be diversified by introducing perennial forage crops. Impacts of such perennial crops on weeds were studied with four approaches : 1) Large-scale weed surveys in 632 fields in western France showed that weed species composition differed most strongly between perennial alfalfa crops and annual crops. Comparisons of fields before, during and after perennial alfalfa suggested that community composition varies in a cyclic way during such crop rotations. Several weed species problematic in annual crops were suppressed during and after perennial crops, but the appearance of other species led to equal or even higher plant diversities. 2) A 3-year field experiment with contrasting crop management options allowed an investigation of the underlying mechanisms for this: The absence of soil tillage reduced weed emergence but increased the survival of established plants. The permanent vegetation cover and frequent hay cuttings reduced weed growth, plant survival and seed production. 3) Greenhouse experiments testing the regrowth ability of individual plants after cutting showed strong differences between species and functional groups. An two-factorial experiment suggested that the negative impacts of cutting and competition on weed growth were mainly additive. 4) Special measurements of weed seed predation in the field experiment showed positive correlations with vegetation cover, indicating that this ecosystem service may be particularly fostered by perennial crops. Consistent preferences of seed predators for certain weed species indicates that seed predation may be another cause of the observed weed community shifts.

La rotation de cultures peut être utilisée pour empêcher la sélection continue d’espèces adventices adaptées à un type de culture. Elle pourrait favoriser la gestion des adventices, l’économie d’herbicides et la biodiversité. Les successions de cultures simples d’aujourd’hui pourraient être diversifiées par des cultures fourragères pérennes. Les impacts des ces cultures sur les adventices ont été étudié utilisant quatre approches : 1) Des relevés d’adventices sur 632 champs dans l’ouest de la France ont montré que la composition spécifique varie le plus entre des cultures fourragères pérennes et des cultures annuelles. Une comparaison des champs avant, pendant, et après des cultures fourragères pérennes a suggéré que la composition des communautés varie d’une manière cyclique pendant ces rotations. Plusieurs espèces problématiques dans des cultures annuelles ont été supprimées pendant et après les cultures pérennes, mais l’apparition d’autres espèces a produit une diversité de plantes comparable, voire supérieure. 2) Une expérimentation au champ de trois ans avec des modes de gestion contrastés a permis d’étudier les mécanismes sous-jacents: L’absence de travail du sol a réduit la levée des adventices, mais a augmenté la survie des plantes adultes. Le couvert végétal permanent et les fauches fréquentes ont réduit la croissance, la survie des plantes et la production de graines. 3) Des expérimentations sous serre analysant la croissance poste fauche de plantes individuelles ont montré des différences importantes entre espèces et groupes fonctionnels. Une expérimentation à deux facteurs a suggéré que les impacts négatifs de la fauche et de la compétition sur la croissance des adventices ont été additifs. 4) Des mesures spéciales de prédation de graines d’adventices sur l’expérimentation au champ ont montré des corrélations positives avec le couvert végétal et la prédation, indiquant une importance particulière de ce service écosystémique dans des cultures pérennes. La préférence des graines de certaines espèces montre que la prédation de graines peut être une autre cause des changements de communautés d’adventices. / Crop rotation may be used to prevent the continuous selection of particular weed species adapted to one crop type. This might be useful for weed management, economy in herbicide applications and promoting biodiversity. Common simple crop sequences might be diversified by introducing perennial forage crops. Impacts of such perennial crops on weeds were studied with four approaches : 1) Large-scale weed surveys in 632 fields in western France showed that weed species composition differed most strongly between perennial alfalfa crops and annual crops. Comparisons of fields before, during and after perennial alfalfa suggested that community composition varies in a cyclic way during such crop rotations. Several weed species problematic in annual crops were suppressed during and after perennial crops, but the appearance of other species led to equal or even higher plant diversities. 2) A 3-year field experiment with contrasting crop management options allowed an investigation of the underlying mechanisms for this: The absence of soil tillage reduced weed emergence but increased the survival of established plants. The permanent vegetation cover and frequent hay cuttings reduced weed growth, plant survival and seed production. 3) Greenhouse experiments testing the regrowth ability of individual plants after cutting showed strong differences between species and functional groups. An two-factorial experiment suggested that the negative impacts of cutting and competition on weed growth were mainly additive. 4) Special measurements of weed seed predation in the field experiment showed positive correlations with vegetation cover, indicating that this ecosystem service may be particularly fostered by perennial crops. Consistent preferences of seed predators for certain weed species indicates that seed predation may be another cause of the observed weed community shifts. / Fruchtfolgen können dazu dienen, die kontinuierliche Selektion von Unkrautarten zu verhindern, die an eine bestimmte Kultur angepasst sind. Dies könnte dem Unkrautmanagement, der Einsparung von Herbiziden, und der Biodiversität dienen. Heutige, sehr einfache Furchtfolgen könnten durch mehrjährige Futterkulturen diversifiziert werden. Die Einflüsse solcher mehrjähriger Kulturen auf Unkräuter wurden in vier Ansätzen untersucht : 1) Vegetationsaufnahmen auf 632 Feldern in Westfrankreich zeigten, dass die Unkrautzusammensetzung zwischen mehrjährigen Futterkulturen und einjährigen Kulturen stark variiert. Der Vergleich von Feldern vor, während und nach mehrjährigen Futterkulturen legte nahe, dass die Pflanzengemeinschaft während solcher Fruchtfolgen zyklisch variiert. Mehrere problematische Unkrautarten wurden während und nach den mehrjährigen Kulturen zurückgedrängt. Das Auftauchen anderer Arten führte jedoch zu einer gleichbleibenden oder leicht erhöhten Pflanzenvielfalt. 2) Ein dreijähriger Feldversuch mit verschiedenen Bearbeitungsoptionen ermöglichte es, die zugrunde liegenden Mechanismen zu untersuchen: Die fehlende Bodenbearbeitung hat das Auflaufen der Unkräuter reduziert und das Überleben der adulten Pflanzen erhöht. Die permanente Vegetationsbedeckung und die häufigen Heuschnitte haben das Wachstum, das Überleben und die Samenproduktion vermindert. 3) Gewächshausexperimente zum Nachwachsen von Unkrautpflanzen nach Heuschnitten zeigten große Unterschiede zwischen verschiedenen Arten und funktionellen Gruppen. Ein Experiment mit zwei Faktoren lässt vermuten, dass die negativen Effekte der Schnitte und der Konkurrenz auf das Unkrautwachstum sich addieren. 4) Spezielle Messungen der Prädation von Unkrautsamen auf den untersuchten Feldern zeigten positive Korrelationen mit der Vegetationsbedeckung, was auf eine besondere Wichtigkeit dieser Ökosystemdienstleistung in ausdauernden Kulturen hindeutet. Die Präferenz von bestimmten Samenarten deutet darauf hin, dass Samenprädation ein weiterer Grund für die beobachteten Änderungen der Unkrautgemeinschaften sein kann.