Outcrops of late Quaternary deposits along the north–east coast of Mallorca were examined, and a high resolution chronological framework established using optically stimulated luminescence of quartz and feldspar grains. Coastal sections at Es Barrancar and Cala Mata record a complex succession of alluvial fan deposition with a minor aeolian component, mainly deposited during the last two glacial cycles. For the last ~200ka different orbital configurations appear to have produced a series of subtly different climatic scenarios that resulted in great variations in the regional availability of moisture. In turn, each of these climatic scenarios set in motion a distinct set of sedimentary processes, which imprinted themselves upon the character of fluvial system response recorded in the alluvial archives on Mallorca. Within the resulting complex of sediments were units of fluvially reworked aeolianite which, although truncated in places, were traceable laterally along wide sections of the sea front outcrops of both fan systems. These archives yielded 47 new OSL and pIRIR290 ages which suggest a number of previously unrecognised periods of enhanced fluvial activity. Luminescence ages identify significant ephemeral fluvial activity taking place during MIS 6, MIS 5 sub-stages d/c, b/a, and across the MIS 5/4 boundary. Another major phase of reworking corresponds with the middle part of MIS 3, and continued sporadically into the Last Glacial Maximum. These fluvial reworking events have been interpreted as having taken place during cold arid climatic intervals, when vegetation was at a minimum, precipitation was low and displayed a much higher degree of seasonality, enhancing the effects of runoff.

Dans les zones cristallines semi-arides, les petits aquifères alluviaux sont des ressources hydrogéologiques limitées, mais importantes pour les populations rurales. La durabilité de leur disponibilité repose sur le développement de stratégies de gestion adaptées aux contraintes physiques mais aussi socioéconomiques locales. Sur un bassin versant situé dans la zone cristalline du Nordeste brésilien semi-aride, où l'utilisation des nappes alluviales s'est développée rapidement depuis 10 ans, a été mise en œuvre une double approche 1) physique afin de caractériser et proposer un modèle de fonctionnement hydrosalin de ces ressources traditionnellement peu étudiées, 2) socioéconomique pour caractériser les groupes d'usagers et les stratégies locales d'utilisation et de gestion des ressources en eau. L'étude s'appuie sur 6 ans de données (suivis et études de caractérisation des milieux physique et anthropique) et sur la construction de modèles de bilans hydrologiques et de masse au pas de temps mensuel qui ont permis de quantifier les termes des bilans de la nappe alluviale et de discuter les interactions avec les autres ressources en eau (aquifère de socle, retenues). Les hypothèses de fonctionnement hydrologique ont été testées avec un modèle spatialisé à base physique. Des scénarios d'évolution de l'exploitation des ressources ont été construits en tenant compte des principales contraintes internes (physiques et anthropiques) et externes (politiques publiques). L'impact de ces scénarios sur la disponibilité en eau (en termes de qualité et quantité) a été simulé à plus ou moins long terme ce qui a permis de montrer qu'une gestion intégrée amont/aval des ressources est bénéfique pour l'ensemble des usagers. Enfin, une méthode régionale de cartographie des petits aquifères alluviaux basée sur la télédétection est développée et permet d'évaluer le volume d'eau potentiellement exploitable sur un grand bassin versant.

Dans la Combe de Savoie , entre Albertville et Montmélian, les alluvions modernes de l'Isère recèlent une nappe en étroite liaison avec les cours d ' eau qui empruntent la vallée. L'objet de cette étude est de définir avec précision le comportement hydrodynamique de l 'aquifère afin d' en déterminer les potentialités . Une première partie sera consacrée à l'analyse des nombreuses données fournies par diverses campagnes de reconnaissance (géophysique , hydrométrie des cours d ' eau , relevés piézométriques réguliers, etc ... ), elle portera essentiellement sur - la définition de la structure du remplissage alluvial, - l'évaluation des paramètres régissant les écoulements souterrains (transmissivité, emmagasinement, etc . .. ) à l ' aide de méthodes analytiques , - la caractérisation climatologique et hydrologique d'une période d'étiage de référence (octobre 1980). Dans une seconde partie, nous réaliserons, à partir des résultats précédents , plusieurs simulations numériques des écoulements souterrains à l'échelle de l'ensemble de la vallée. La mise en oeuvre de ce modèle mathématique conduit à évaluer sommairement les potentialités actuelles de l'aquifère qui permettent d'ores et déjà d'envisager un premier schéma d'exploitation de cette ressource en eau.

L'objectif de la recherche est l'etude de l'evolution morphogenique et du detritisme alluvial dans le bassin de la moyenne Durance. Plusieurs methodes sont utilisees : l'analyse geomorphologique et sedimento-stratigraphique des depots ; l'etude dendrogeomorphologique d'un bassin de "terres noires" dans lequel les sediments postglaciaires contiennent un gisement important d'arbres subfossiles; l'etude geo-archeologique de plusieurs sites de plaine alluviale ; l'exploitation des donnees d'archives (textes et cartes anciennes). Les organismes fluviaux de rang inferieurs connaissent un alluvionnement important a partir de l'Allerod jusqu'a la periode atlantique, l'essentiel de la sedimentation s'effectuant au boreal. Plusieurs crises detritiques sont mises en evidence, au debut du dryas recent, a la fin du preboreal, au boreal et au debut de l'atlantique. Elles succedent a des periodes de stabilite des fonds alluviaux, de developpement d'un couvert vegetal arborescent de pins sylvestres (pinus silvestris) (bois subfossiles). Ces nappes alluviales temoignent de crises climatiques caracterisees par une frequence elevee d'episodes pluvieux de forte intensite. Nos resultats s'accordent bien avec les interpretations paleoclimatiques recentes. La periode atlantique est caracterisee par une phase de pedogenese sur les versants, une attenuation de la sedimentation dans les talwegs puis une reprise de l'incision. Cette evolution temoigne d'une reduction des flux detritiques et d'une concentration des ecoulements en relation avec un "optimum forestier" et des regimes de precipitation plus reguliers. Enfin, plusieurs nappes alluviales se mettent en place au cours de la seconde partie de l'holocene, a la charniere de l'atlantique et du subboreal, au cours des ages des metaux (age du fer), a la fin de l'antiquite et durant les temps modernes. Elles sont en relation avec des deteriorations climatiques et les effets des modes de mise en valeur par les societes humaines. Cette etude souligne le role souvent determinant de la variable climatique dans l'evolution de la morphogenese fluviale sud-alpine, le parametre anthropique ne jouant qu'un role subsidiaire.

The aim of the study was to investigate the diversity and ecological properties of Dothideomycetes and Sordariomycetes in the alluvial black alder forests and the pine forest affected by cormorants. For the first time in Lithuania, detailed investigations were carried out on the diversity and distribution of Dothideomycetes and Sordariomycetes in the above-mentioned forests. The checklist of the study fungi was complied. 72 Dothideomycetes and Sordariomycetes species new to Lithuania were identified and original descriptions of their morphology were provided. The influence of abiotic factors on the diversity of woody and herbaceous plants fungi was evaluated for the first time in Lithuania. The results of the study enhanced the knowledge about the distribution of Dothideomycetes and Sordariomycetes in the alluvial forests protected in Europe, which may be used to protect the biologic diversity of these habitats. The properties of the diversity and distribution of studied fungi in the pine forest affected by cormorants allow assessing the impact of the hypertrophication, caused by these birds on the pine forest mycobiota. / Darbo tikslas – ištirti dotidėjomicetų (Dothideomycetes) ir sordarijomicetų (Sordariomycetes) įvairovę bei ekologines ypatybes aliuviniuose juodalksnynuose ir kormoranų pažeistame pušyne. Darbe pirmą kartą Lietuvoje detaliai ištirta aliuviniuose juodalksnynuose ir kormoranų pažeistame pušyne dotidėjomicetų ir sordarijomicetų rūšių įvairovė ir paplitimas. Sudarytas šiuose miškuose aptiktų grybų rūšių sąvadas. Išaiškintos 72 naujos Lietuvai tirtų aukšliagrybūnų rūšys ir pateikti originalūs jų morfologijos aprašymai. Pirmą kartą Lietuvoje įvertinta aplinkos veiksnių įtaka sumedėjusių bei žolinių augalų dotidėjomicetų ir sordarijomicetų įvairovei. Darbo rezultatai pagilino žinias apie šių grybų paplitimo dėsningumus Europoje saugomuose aliuviniuose miškuose, kas gali būti panaudota šių buveinių biologinės įvairovės išsaugojimui. Kormoranų pažeistame pušyne nustatyti tirtų grybų rūšinės sudėties ir paplitimo ypatumai leidžia įvertinti šių paukščių sukeliamos hipertrofikacijos poveikį pušyno mikobiotai.

Low-lying coastal plains comprised of unconsolidated infill are internally complex hydrogeological settings, due to the high level of heterogeneity in the infill material. In order to resolve the hydrogeological processes active in these complex settings, an integrated multi-disciplinary, geoscientific approach is required. This research determines quantitatively, the effects of sedimentary aquifer heterogeneity on groundwater flowpaths and groundwater processes within a heavily laterised, coastal plain setting. The study site is the Bells Creek catchment in southeast Queensland, Australia. The methodology developed in this study provides a new approach to enable the determination of groundwater flowpaths and groundwater processes at macroscale resolution within other shallow alluvial and coastal plain aquifers. The multi-disciplinary approach utilises sedimentological, geophysical, chronological and hydrogeological techniques (including hydrochemistry and groundwater flow modelling) to develop a high-resolution aquifer framework, and to determine accurately, both groundwater flowpaths and relative flow rates. Sedimentary framework is confirmed to be the principal factor controlling the distribution of aquifer permeability pathways in any given setting, and is therefore, the dominant control over groundwater flow and processes. For the Bells Creek catchment, interpretation of stratigraphic and sedimentary data allowed the compilation of a detailed sedimentary framework. This interpretation demonstrated that weathering of the low-lying arkose sandstone bedrock has developed thick lateritic profiles. Within the weathering profiles, cemented, iron-rich horizons have resisted erosion and developed raised and elongated ridges in the modern landscape, while other clay-rich weathered layers have submitted to erosion and downgraded around those iron-rich ridges. Consequently, alluvial deposition throughout the Late Quaternary has been restricted to narrow, and relatively deep valleys containing sandrich channels, and thin floodplains at shallow depth. From a hydrogeological perspective, there is significant macroscopic aquifer heterogeneity between fine-grained lateritic mixed clay layers, floodplain clays, ironcemented ferricrete horizons, and permeable sand-rich alluvial aquifers. This variability of aquifer material has created a complex subsurface arrangement of permeability pathways. Application of Ground Penetrating Radar (GPR) in this setting enabled accurate definition of alluvial channel boundaries and the high degree of connectedness within the channels themselves. Interpretation of a comprehensive GPR dataset (that covered the entire catchment) allowed refinement of the sedimentary framework previously established to develop a detailed threedimensional aquifer framework. Finite-difference groundwater modelling and particle tracking analysis (using MODFLOW and MODPATH) has clearly demonstrated that the macroscopic heterogeneity within the various aquifer materials of the plain has marked impacts on groundwater pathways, and especially groundwater travel times. The variability between a maximum residence time of 18 months for groundwater within the alluvium, compared to hundreds of years for groundwater within the mixed clay layers of the laterite, clearly demonstrates the importance of accurately defining the spatial distribution of the various aquifer materials in a groundwater flow investigation. In this setting, the interconnection of the narrow alluvial channels feeding into a deeper alluvial delta has provided an effective conduit for shallow groundwater flow. The role of the alluvial delta in discharging the bulk of fresh groundwater from the central plain into the coastal and estuarine aquifers to the east, is certainly critical in preventing saline intrusion from encroaching further west. Hydrochemical and isotopic indicators have identified the dominant recharge processes and groundwater flowpaths within the plain, and indicated that the processes are strongly related to sub-surface permeability distributions determined in the aquifer framework (and groundwater modelling), as well as seasonal fluctuations in rainfall. In the northwest of the plain, sandstone hills provide a delayed and slightly mineralized component of groundwater recharge into adjacent highly permeable, unconfined alluvial aquifers; these aquifers also recharge directly via precipitation. Aluminosilicate weathering in the bedrock hills and eastern peripheries of the laterised bedrock are a source of excess Na, SiO2, and HCO3 to the alluvial groundwater. As this groundwater flows down-gradient to the east, however, its chemical composition evolves by sulfate reduction, silica equilibrium and ion exchange processes into a more mature Na-Cl type. Within the shallow coastal aquifers proximal to the eastern shoreline, sulfate enrichment is occurring (associated with increases in Ca, HCO3, Fe and Al) resulting in major deterioration in groundwater quality. The deterioration is produced by saline intrusion from the adjacent estuary coupled with oxidation of sulfide materials in shallow marine and estuarine clays. Reverses in salinity in those coastal aquifers have been correlated with surges in fresh recharge waters from unconfined coastal dunes and semi-confined landward alluvium, following significant rainfall events. The multi-disciplinary methodology developed, provides an effective approach for accurately defining the three-dimensional distribution of shallow aquifer material of varying permeability via detailed stratigraphic interpretation and GPR analysis. Utilising this aquifer framework, finite-difference groundwater modelling aided by hydrogeological data and hydrochemical analysis, allows accurate determination of groundwater flowpaths and groundwater processes. This research provides a new hydrogeological analogue for alluvial channel aquifers within a laterised coastal plain setting. Key Words: groundwater flow, aquifer heterogeneity, numerical modelling, hydrochemistry, recharge, ground penetrating radar, coastal plain aquifers, weathering, alluvial channels.

This thesis aims at deciphering the respective roles of autogenic processes and allogenic forcing in the post-orogenic evolution of a coupled mountain catchment/foreland megafan system, with a focus on the Lannemezan megafan and its mountainous catchment in the northern Pyrenees (France). AFT data are consistent with previously published thermochronological data, showing (i) the main exhumation phase of the Axial Zone (AZ; ~50-30 Ma) with lateral variations in the exhumation rates, (ii) a later unroofing of the North-Pyrenean Zone (NPZ; since ~20 Ma), and (iii) a late (~20-15 Ma) exhumation phase only recorded in the western part of the range (west of the Neste River). The megafan was thus built at a late stage of the orogeny and its source catchment lays on the boundary between two tectonic domains. Petrographic data shows that the source area encompasses the NPZ and AZ but modern river sands yield more granitic material than the megafan sediments. This discrepancy suggest that (i) the foreland deposits are locally sourced, but this is not consistent with the definition of a megafan, (ii) the crystalline massifs may have been insufficiently unroofed, but this is inconsistent with the presence of granitic material in Eocene deposits of the south foreland, (iii) the main drainage divide migrated to the south around that period, but this seems inconsistent with the exhumation history of the range as inferred from thermochronological data. Comparison of my estimation of the sedimentary budget and AFT-derived exhumation rates suggests that the current watershed of the Neste is more than sufficient to provide the material for the building of the Lannemezan megafan. This implies that (i) the catchment boundaries have not necessarily changed since the Miocene and (ii) a significant portion of the sediments bypassed the megafan. I dated the abandonment of Quaternary surfaces using cosmogenic nuclides (10Be, 26Al). The abandonment of the megafan (~300 ka) and of the alluvial terraces (~100ka, ~20ka and ~1ka) suggests that incision episodes are triggered by cold-to-warm climatic shifts. The terrace slopes increase with time: I propose that the region was subjected to northward tilting by flexural isostatic rebound as a response to erosional unloading of the range during the Quaternary. From the morphometric analysis (χ-proxy, steepness index, concavity, long river profiles) I show (i) drainage reorganization near the megafan apex and (ii) no influence on the drainage network from active tectonic structures or base-level variations. The abandonment and of the Lannemezan megafan is thus linked to the capture of the Neste by the Garonne and its episodic incision is linked to Quaternary climatic cycles. Numerical modelling adequately reproduce the building of a large megafan in 15 Ma by progradation of the deposits carried by a central river that becomes dominant in the sediment routing. I suggest that, in the northern Pyrenean foreland, the Atlantic Ocean to the west and large, efficient rivers create the conditions needed for a river to be singled out and build a megafan. Negligible subsidence at during the Miocene may have encouraged progradation. I suggest that, in the northern Pyrenees, the main driving force for long-term entrenchment of the megafan is linked to autogenic processes but these are modulated by short-term climatic changes (and possibly isostatic movements). Numerical modelling also evidenced the strong coupling between the mountainous catchment and the basin and the characteristic response times (on the order of 10 ka). / Le but de cette thèse est de comprendre ce qui contrôle l’évolution géomorphologique post-orogénique d’un ensemble composé d’un bassin versant montagneux et de son piedmont à partir de l’exemple du méga-cône alluvial de Lannemezan et son bassin versant au flanc nord des Pyrénées. Les données de thermochronologie in-situ et détritiques confirment les phases d’exhumations : (1) une phase d’exhumation majeure (~50-30 Ma), enregistrée dans toute la ZA bien qu’avec des vitesses différentes à l’est (Ariège) qu’à l’ouest, (2) une excavation plus tardive de la ZNP (à partir de ~20 Ma), et (3) une phase tardive d’exhumation (vers 15-20 Ma) enregistrée seulement à l’ouest. Le méga-cône se forme donc à une période post-orogénique où la tectonique cesse de jouer un rôle dominant, mais le bassin versant d’alimentation du cône se situe à une position charnière entre deux zones qui s’exhume différemment. Les données de pétrographie des sédiments indiquent une zone source qui inclut la ZNP et la ZA. La proportion de matériel cristallin dans les sédiments Oligo-Miocène est plus faible que celle des sédiments des rivières actuellesce qui pourrait suggérer que (1) les massifs cristallins n’étaient pas suffisamment exhumés mais cela semble incohérent avec les études précédentes, (2) que la ligne de partage des eaux a migré vers le sud, mais ce n’est pas cohérent avec l’histoire d’exhumation de la chaîne. J’ai comparé le volume érodé dans le bassin pour produire le méga-cône et le flux sédimentaire estimé à partir des taux d’exhumation : il semble que le bassin versant actuel de la Neste est plus que suffisant pour produire les sédiments du cône, ce qui suggère que (1) la taille du bassin versant n’a pas nécessairement changé et (2) une partie des sédiments a été directement exportée vers le bassin marin. Les résultats des datations par nucléides cosmogéniques (10Be et 26Al) suggèrent que le cône est abandonné vers ~300 ka et les terrasses alluviales qui bordent les rivières du piémont (~100ka, ~20ka et ~1ka) pourraient suggérer un contrôle climatique sur l’incision (cycles glaciaires/interglaciaires). Pour expliquer la pente des terrasses je propose l’hypothèse d’un basculement de la région en lien avec un rebond isostatique au Quaternaire. L’analyse morphométrique du réseau de drainage montre (i) une réorganisation par capture dans la partie sud du cône et (ii) qu’il n’y a pas de structure tectonique active ou de variation du niveau marin. J’ai utilisé un modèle numérique pour comprendre les conditions de formation et d’incision d’un méga-cône et comparé les résultats avec les observations faites sur le cône de Lannemezan et son bassin versant. Les résultats suggèrent que le temps de construction d’un tel cône est de l’ordre de 15 Ma, par progradation des dépôts d’une rivière centrale qui domine les apports du piémont. La comparaison avec le cas de Lannemezan suggère que (1) l’Océan Atlantique à l’ouest et les grandes rivières, au transport efficace créent un environnement propice à la formation du méga-cône; (2) la subsidence négligeable du piémont pourrait avoir favorisé la construction du méga-cône; (3) les processus autogéniques sont suffisants pour produire au long terme une incision permanente du cône par sa rivière d’alimentation. Les forçages externes (tectoniques, climat) ne font que moduler l’incision autogénique. La réponse du paysage à un forçage climatique cyclique montre un temps caractéristique de l’ordre de 10 ka. Finalement, la modélisation a permis de mettre en évidence les interactions entre le piémont et la chaîne.

The thesis is part of project "Bohemian Revitalization of wetlands and peatlands". The aim is to catch up the current state (before revitalization) of vegetation and flora with possibility of the existence of rare endagered species in Fir Stream plains in the Southern Bohemia, district Prachatice, cadastral area Volary. There was engaged generic list of plants in this interest locality. There was defined by the 6 permanent areas with dimensions 4x4 m. I made a complete inventory of all found species. Overall, it was found 38 plant species: 11 monocotyledonous plants, 25 dicotyledonous plants and 2 bryophytes.

Made available in DSpace on 2016-12-12T20:12:30Z (GMT). No. of bitstreams: 1 PGEF14MA029.pdf: 198397 bytes, checksum: 07438924f0f85be86d62319592d6c9cf (MD5) Previous issue date: 2014-12-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / We aimed to evaluate the natural regeneration in an Alluvial Araucaria Forest fragment, in Planalto Sul Catarinense region. Two chapters are presented, with the first chapter with the objectives of i) to inventory the natural regeneration of tree species; ii) to evaluate the similarity between the regenerative and adult component within the fragment; and iii) to verify the floristic sharing of natural regeneration among forests remnants in the region; and the second chapter with the aim of to determine the influence of environmental heterogeneity on regenerative component within the fragment; ii) to determine the correlation between the vegetation and the environmental sectorization; and iii) to determine the indicator species in each studied sectors. The regenerative component was sampled in 48 plots allocated in three sectors: edge adjacent to the river, fragment interior and edge adjacent to grassland matrix, with 16 plots in each sector. The regenerative individuals were identified and classified according to the height: Class 1, plants with height from 15 cm up to 1 m; Class 2, plants with height from 1 up to 3 m; Class 3, plants with height higher than 3 and diameter at breast height (dbh) smaller than 5 cm. The composition of adults of the study area and of regenerative individuals from other fragments were obtained from the 20 database of the Laboratory of Dendrology of the CAV/UDESC. The environmental variables survey was conducted in all plots, being obtained the data of edaphic, canopy cover, environmental impacts, groundwater level, topography and soil type. The evaluation of floristic-structural composition of regenerating was conducted through phytosociological descriptors and the similarity between regenerative and adults components was determined by Jaccard, Sorensen and Bray-Curtis Indices. The analyses of floristic sharing of the regeneration with other areas was conducted by a dendrogram. The existent environmental gradient in the study area was analyzed by a Principal Component Analysis (PCA). The significance of environmental sectors on the regenerative component was evaluated through generalized linear models (GLM). The floristic-structural organization of regenerative component was verified trough a Principal Coordinates Analysis (PCoA), with indicator species determined for each significant environmental sector. The species with the greatest relative importance value was Allophylus edulis (A.St.-Hil. et al.) Hieron. ex Niederl. The similarity between the adult and regenerative components was high (0.57 to 0.76), indicating a trend of low floristic-structural turnover over time. The studied area showed a higher floristic connection with other spatially close fragments, suggesting that altitude and temperature represent important ecological factors on phytogeographic compartmentalization of this component. The sectoring according to distance from the river was a significant factor. The edge adjacent to grassland matrix sector present the most distinct floristic and structural composition, with 14 indicator species, while in the sectors edge adjacent to the river and interior there was, respectively, one and no indicator species. We conclude that the regenerative component presented spatial 22 variation that reflects the existing environmental heterogeneity in the area / O objetivo da presente dissertação foi avaliar a regeneração natural em um fragmento de Floresta Ombrófila Mista Aluvial, na região do Planalto Sul Catarinense. São apresentados dois capítulos, em que o primeiro teve como objetivos: i) inventariar a regeneração natural de espécies arbóreas; ii) avaliar a similaridade entre o componente regenerante e adulto do fragmento; e iii) verificar o compartilhamento florístico da regeneração natural entre fragmentos na região. O segundo capítulo objetivou: i) determinar a influência da heterogeneidade ambiental sobre o componente regenerante do fragmento; ii) determinar a correlação entre vegetação e setorizações ambientais; e iii) determinar as espécies indicadoras de cada setor no fragmento estudado. O estrato regenerante foi amostrado em 48 parcelas alocadas em três setores: borda adjacente ao rio, interior do fragmento e borda adjacente à matriz campestre, com 16 parcelas por setor. Os indivíduos regenerantes foram identificados e classificados de acordo com a altura em: Classe 1, plantas com altura entre 15 cm e 1 m; Classe 2, plantas com altura entre 1 e 3 m; e, Classe 3, plantas com altura maior que 3 m e diâmetro à altura do 14 peito (DAP) menor que 5 cm. A composição dos indivíduos adultos da área e de regenerantes de outros fragmentos foi obtida do banco de dados do Laboratório de Dendrologia do CAV/UDESC. O levantamento das variáveis ambientais foi realizado em todas as parcelas, sendo obtidos os dados das variáveis edáficas, abertura do dossel, impacto ambiental, nível do lençol freático, topografia e classe de solo. A avaliação da composição florístico-estrutural dos regenerantes foi feita por meio de descritores fitossociológicos e a similaridade entre o componente regenerante e adulto foi determinada por meio dos índices de Jaccard, Sorensen e Bray-Curtis. A análise do compartilhamento florístico da regeneração com outras áreas foi realizada por meio de um dendrograma. Os gradientes ambientais existentes na área foram determinados por meio da Análise de Componentes Principais (PCA). A significância dos setores ambientais sobre o componente regenerante foi avaliada por meio de modelos lineares generalizados (GLM). A organização florística-estrutural do componente regenerante foi verificada por meio de uma Análise de Coordenadas Principais (PCoA), sendo, ainda, verificadas as espécies indicadoras para os setores. A espécie de maior importância relativa foi Allophylus edulis (A.St.-Hil. et al.) Hieron. ex Niederl. A similaridade entre componente adulto e regenerante foi elevada (0,57 a 0,76), indicando uma tendência de baixa substituição florístico-estrutural ao longo do tempo. A área estudada apresentou maior vínculo florístico com outros fragmentos espacialmente próximos, sugerindo que altitude e temperatura representam importantes fatores ecológicos na compartimentalização fitogeográfica deste componente. A setorização foi significativa pelo fator distância do rio. O setor borda adjacente à matriz campestre foi o que apresentou a composição florística-estrutural mais distinta, e 14 espécies indicadoras, enquanto o setor borda adjacente ao rio e o setor 16interior apresentaram uma e nenhuma, respectivamente. Conclui-se que o componente regenerativo apresentou variações espaciais que refletem a heterogeneidade ambiental existente na área

Made available in DSpace on 2016-12-12T20:12:32Z (GMT). No. of bitstreams: 1 PGEF15MA043.pdf: 302159 bytes, checksum: 356c59259d1f7d46382f6efeff6b11e4 (MD5) Previous issue date: 2015-05-29 / This dissertation aimed to investigate the influence of spatial structure and environmental variables on floristic-structural organization of the tree component in an Araucaria Forest, in Santa Catarina. For this, 48 200 m2 sampling units were allocated in a forest remnant, located in an alluvial plain along Caveiras river, in the municipality of Lages, SC. All trees within sampling units with diameter at breast height, measured at 1.30 m above the ground (dbh), equal to or greater than 5 cm were measured and identified. The environmental variables measured in each sampling units were: water table level, chemical and physical soil properties, topography, canopy cover and environmental impacts. The spatial variables were determined using the analysis of principal coordinates of neighbour matrices (PCNM), through the geographic coordinates from each sampling units. The data were analyzed through Mantel Correlogram, Variation Partitioning, Redundancy Analysis (RDA s) and correlation tests. A total of 1,462 individuals, belong to 66 species, were sampled. Together, the environmental and spatial variables explained 24,13% of total variation, with the largest part (15,22%) being spatially structured. The most significant environmental variables were topography (maximum elevation difference) and fertility (bases sum and P). It is possible to conclude that the tree component is organized as a floristic-structural gradient. Futhermore, the results suggest that the inundation regime and the presence of flood prone areas were relevant for micro-habitats definition, that influenced the distribution of species / A presente dissertação teve como objetivo investigar a influência da estruturação espacial e de variáveis ambientais sobre a organização florístico-estrutural do componente arbóreo em uma Floresta Ombrófila Mista Aluvial, em Santa Catarina. Para isso, foram alocadas 48 unidades amostrais de 200 m2 no remanescente, localizado em uma planície aluvial nas margens do rio Caveiras em Lages, SC. Todos os indivíduos dentro das unidades amostrais com diâmetro na altura do peito, medido a 1,30 m do solo (DAP), igual ou superior a 5 cm foram mensurados e identificados. Foram mensuradas as variáveis ambientais em cada uma das unidades amostrais: nível freático, propriedades químicas e físicas nos solos, topografia, cobertura do dossel e impactos ambientais. As variáveis espaciais foram determinadas por meio da análise de Coordenadas Principais de Matrizes Vizinhas (PCNM), a partir das coordenadas geográficas de cada unidade amostral. Os dados foram analisados por meio de Correlograma de Mantel, Particionamento da Variância, Análises de Redundância (RDA s) e testes de correlação. Foram amostrados 1.462 indivíduos pertencentes a 66 espécies. Conjuntamente, as variáveis ambientais e espaciais explicaram 24,13% da variação total, sendo que a maior parte (15,22%) encontrou-se espacialmente estruturada. Das variáveis ambientais, a topografia (desnível máximo) e a fertilidade do solo (soma de bases e P) foram as mais significativas. Conclui-se que o componente arbóreo está organizado na forma de um gradiente florístico-estrutural. Ainda, os resultados sugerem que o regime de inundação do rio e a presença de zonas de maior encharcamento do solo foram relevantes na definição de micro-habitats, que influenciaram na distribuição das espécies