Esta pesquisa analisou a trajetória intelectual e a produção científica do naturalista sueco Johan Albert Constantin Löfgren (1854-1918) contribuindo, assim, com a história das ciências naturais no Brasil na transição entre os séculos XIX e XX. Para atingirmos este objetivo realizamos uma análise do conteúdo da sua produção técnico-científica para identificamos a estruturação das suas publicações (temáticas e abordagens predominantes). Este processo possibilitou a seleção dos tópicos aprofundados na análise do discurso, cuja decodificação revelou a visão de ciência e o papel do conhecimento; o conteúdo geográfico a ele inerente, vinculado à formação e organização do espaço e de formação da identidade nacional; seu pioneirismo em várias áreas do saber; sua atuação em importantes instituições de pesquisa; e, a atualidade de seu pensamento. Apesar de estrangeiro, Löfgren inseriu-se muito bem na sociedade brasileira do século XIX: estabeleceu relações sociais; manteve contato com o governo de diversas províncias e com instituições científicas nacionais e internacionais; e, assumiu a chefia de importantes seções ligadas a institutos de pesquisas, tais como a Seccção Botanica e Meteorologia da Commissão Geographica e Geologica de São Paulo, o Museu Sertório (atual Museu Paulista), o Horto Botânico (atualmente conhecido como Horto Florestal, Parque Estadual Albert Löfgren), a Secção de Botânica da Inspetoria de Obras Contra as Seccas, e Secção de Botânica do Jardim Botânico do Rio de Janeiro. Revelando a influência que as visões de ciência de Humblodt e Ritter tiveram em sua formação, Löfgren valorizou o entendimento da influência do meio físico nas sociedades e se dedicou à preservação de peças de arqueologia e de história natural, em particular dos sambaquis do litoral paulista. Por sua iniciativa, foi organizado o serviço meteorológico em São Paulo e no Jardim Botânico do Rio de Janeiro. Dedicou-se ao estudo da flora brasileira sob a ótica evolucionista, descrevendo seus aspectos fisionômicos e florísticos, sendo o primeiro a indicar um sistema para caracterizar os tipos e formas de vegetação do Cerrado. Löfgren envolveu-se no discurso científico durante o processo de formação e organização do espaço e da identidade nacional. Seus estudos sobre o potencial agrícola dos campos paulistas e do semiárido nordestino o levaram a combater a prática das queimadas e a dedicação exclusiva à monocultura. Ao denunciar os danos ambientais provocados pelo avanço das atividades econômicas e pelo crescimento desordenado das cidades, conseguiu o apoio de outros conservacionistas, que também se ergueram em defesa dos recursos florestais. Sua maior luta foi pela implantação de um serviço florestal que, por força de lei, garantisse a conservação das florestas. Albert Löfgren foi um cientista de seu tempo e criativo nas análises, propostas e prognósticos futuros. Um personagem da história da ciência paulista e brasileira, pouco conhecido e valorizado, cuja ampla contribuição, se colocada em prática, teria resultado em cenários melhores dos que existem hoje. O resgate histórico, a sistematização e a análise de sua produção permitiram fazer jus à sua memória científica e divulgar seu papel no entendimento do mundo geográfico paulista nos finais do século XIX e início do XX. / This research analyzed the intellectual and scientific history of the swedish naturalist Johan Albert Constantin Löfgren (1854-1918) thereby contributing to the history of natural sciences in Brazil in the transition between the nineteenth and twentieth centuries. To achieve this goal we performed a content analysis of its technical-scientific production, to identify the structuring of his publications (predominant themes and approaches). This process enabled the selection of topics in-depth discourse analysis, which revealed the decoding view of science and the role of knowledge; geographic content to it inherently linked to the formation and organization of space and formation of national identity; his pioneering work in several areas of knowledge; his performance in major research institutions; and the current of his thought. Despite being foreign, Löfgren was introduced into Brazilian society of the nineteenth century: established social relations; maintained contact with the government of various provinces and with national and international scientific institutions; and assumed leadership of important sections linked to research institutes, such as Section Botany and Meteorology of Geographical and Geological Commission of São Paulo, the Museum Sertório (now Museu Paulista), the Horto Botânico (now Horto Florestal, Albert Löfgren State Park), Section of Botany, of Inspetoria de Obras Contra as Seccas, and the Section of Botany of Botanical Garden of Rio de Janeiro. Revealing the influence that the visions of science of Humblodt and Ritter had in his formation, Löfgren gave importance to the understanding of the influence of the physical environment in the societies, and was dedicated to the preservation of archaeological and natural history artifacts, in particular the sambaquis on the coast of São Paulo. By his initiative, was organized the weather service in São Paulo and in the Botanical Garden of Rio de Janeiro. He devoted himself to the study of flora in the evolutionary perspective, describing its physiognomic and floristic aspects, and was the first to indicate a system to characterize the types and forms of Cerrado vegetation. Löfgren engaged in scientific discourse during the formation and organization of space and national identity. His studies on the agricultural potential of the fields in São Paulo and of semi-arid Northeast led him to combat the practice of burning and the dedication to monoculture. Denouncing the environmental damage caused by the advancement of economic activities and the unplanned growth of cities, won the backing of other conservationists, who also rose in defense of forest resources. His biggest fight was for the establishment of a forest service that, by law, guarantees the conservation of forests. Albert Löfgren was a scientist of his time and creative in the analyzes, proposals and future predictions. A character in the history of São Paulo and Brazilian science, little known and valued, whose large contribution, if put into practice, would result in the best scenarios that exist today. The historical review, systematization and analysis of his production allowed doing justice to his memory scientific and disseminating his role in the understanding of the São Paulo geographic world in the late nineteenth and early twentieth centuries.

The conformation of urban green spaces comes from a historical construction, resulting from the configurations in the society-nature relationship that shapes this landscape. It is observed in the phytogeography of the urban space, a dialectical process between the thesis of its natural determinants and, the antithesis of its socio-cultural scope. The urban landscape is established as a materialization of a political project of society in the cities which intensifies and concentrates exploration and social-environmental impact. The present thesis analyzes phytogeography in Aracaju / SE and its correlations with urban socioenvironmental aspects, based on geographical and historical conditions, modeling techniques and geoprocessing. With this purpose, bibliographic, statistical and geographic data surveys were carried out; besides fieldwork with the use of Unmanned Aerial Vehicle to elaborate an audiovisual collection. The results were gathered in a geographic database, in which editing, restitution, photointerpretation, geostatistical modeling and analysis were performed. These results allowed a socio-environmental characterization of Aracaju wich was made through a integrated approach by the spheres of water, land and air and their impacts; of urbanization, population and their services; and finally, of the uses of the soil, phytogeographic and socioenvironmental modeling. The roads and sidewalks of Aracaju have some afforestation; orthogonal aspect, longitudinal and woody structures that have their local contexts and need species selection and diversification. There is also a lack of better distribution of the squares, since they are more concentrated and better equipped in the historical or higher-income neighborhoods. The neighborhoods Jardins, Treze de Julho and Coroa do Meio are emblematic examples of a socio-spatial segregation process that has resulted in high investments and environmental impacts. It should be emphasized that changes in landscape dynamics, socio-environmental impacts and phytogeography need to be explained from the society-nature relationship, in order to promote a more functional, structural and equitable afforestation in the urban space. / A conformação dos espaços verdes urbanos é proveniente de uma construção histórica, resultante das configurações na relação sociedade-natureza que modelam essa paisagem. Observa-se na fitogeografia do espaço urbano, um processo dialético entre a tese de seus condicionantes naturais e, a antítese de seu âmbito sociocultural. A paisagem urbana é estabelecida como a cristalização de um fazer geopolítico de sociedade que promove a intensificação e concentração da exploração e dos impactos socioambientais. A presente tese analisa a fitogeografia em Aracaju/SE e suas correlações com aspectos socioambientais urbanos, com base em condicionantes geográficos e históricos, técnicas de modelagem e geoprocessamento. Com esta finalidade, foram realizados levantamentos de dados bibliográficos, estatísticos e geográficos; além de trabalhos de campo com a utilização de Veículo Aéreo Não Tripulado para elaboração de um acervo audiovisual. Os dados coletados foram congregados em um banco de dados geográfico, no qual foram realizados processos de edição, restituição, fotointerpretação, modelagem geoestatística e análises. Esses resultados possibilitaram uma caracterização socioambiental de Aracaju a partir da abordagem integrada das esferas das águas, da terra, do ar e seus impactos; da urbanização, população e serviços; e por fim, dos usos do solo, fitogeografia e modelagem socioambiental. As vias e calçadas de Aracaju possuem certa arborização; aspecto ortogonal, a partir de eixos estruturantes longitudinais arborizados que apresentam seus contextos locais e necessitam de seleção e diversificação de espécies. Observa-se ainda, uma carência de melhor distribuição das praças, pois elas estão mais concentradas e melhor equipadas nos bairros históricos ou de maior renda. Os bairros Jardins, Treze de Julho e Coroa do Meio são exemplos emblemáticos de um processo de segregação socioespacial que acarretou em elevados investimentos e impactos ambientais. Salienta-se portanto, que as transformações na dinâmica da paisagem, os impactos socioambientais e a fitogeografia precisam ser explicados a partir da relação sociedade-natureza, com a finalidade de promover ao espaço urbano uma arborização mais funcional, estrutural e equitativa. / São Cristóvão, SE

Este trabalho faz parte do projeto Biota/FAPESP, Métodos de Inventário da Biodiversidade de Espécies Arbóreas, e analisou a diferença na estrutura florística entre as áreas estudadas. Na Estação Ecológica de Assis, SP, área de Cerradão, foram amostradas 102 espécies, 72 gêneros e 43 famílias; 67% das espécies foram exclusivas desta fitofisionomia. Na Floresta Estacional Semidecidual da Estação Ecológica dos Caetetus, município de Gália-SP, foram amostradas 208 espécies, 138 gêneros e 49 famílias; sendo 65% das espécies exclusivas. Na Floresta Ombrófila Densa do Parque Estadual de Carlos Botelho, município de São Miguel Arcanjo-SP, foram encontradas 410 espécies, pertencentes a 152 gêneros e 64 famílias; 84% das espécies exclusivas desta fitofisionomia. A Floresta Estacional apresentou maior similaridade com a Floresta Ombrófila do que com o Cerradão. Apesar de apresentar maior número de espécies, a Floresta Ombrófila Densa apresenta concentração de espécies nas famílias Myrtaceae e Lauraceae. Em outra análise foram calculados os índices de distinção taxonômica nas 5 grades amostrais para os métodos de amostragem testados. O método de Bitterlich apresentou tendência nos índices de diversidade e distinção taxonômica, conforme a diversidade taxonômica do sub-bosque. Esses índices apresentaram média independente e variância decrescente com o aumento da amostra. Os índices de distinção taxonômica média e variância da distinção taxonômica média também apresentaram variância decrescente. Porém, a estabilização da média ocorreu com amostras de maior tamanho, principalmente para as parcelas de área fixa na Estação Ecológica dos Caetetus. Na Floresta Ombrófila Densa, a distinção taxonômica média foi menor e a variância da distinção taxonômica média foi maior, devido a alta concentração de espécies de Myrtales e Laurales nesta fitofisionomia. / This research is part of the project Biota / FAPESP, \"Tree Species Biodiversity Inventory Methods, and analised floristic structural differences among three areas. In Assis Ecological Station, Forest Savanna area were sampled 102 species, 72 genus and 43 families, 67% of this species were exclusive of this phytophisiognomy. Semideciduous seasonal forest in the Caetetus Ecological Station, 208 species were sampled, 138 genus and 49 families, with 65% of exclusive species. Rain Forest in the Carlos Botelho State Park, were found 410 species, belonging to 152 genus and 64 families, 84% of exclusive species. The seasonal forest showed greater similarity to the rain forest than the Savanna. In spite of the greater number of species, the Rain Forest presents concentration of species in the Myrtaceae and Lauraceae families. In another analysis were calculated the taxonomic indices in tree species data provided by sampling methods tested in five sampling grids. The Bitterlich sampling method was tendecious in estimates the taxonomic diversity and taxonomic distinctness indices because the taxonomic diversity in the understory. These indices showed average independent and variance decreasing with increasing sample. The average taxonomic distinctness and variation in taxonomic distinctness also showed decreased, but the stabilization of the average occurred with samples of greater size, mainly for fixed area plots at Caetetus Ecological Station. In the Rain Forest the average taxonomic distinctness was lower and the variation of taxonomic distinctness was higher due to high concentration of species of Myrtales and Laurales in this phytophisiognomy.

Apesar dos esforços na realização de pesquisas com primatas na Mata Atlântica, ainda existem poucos estudos relacionando topografia, composição e distribuição de vegetação com o padrão de ocupação da área por primatas. Pela escassez dessas pesquisas, essas relações foram analisadas em duas áreas dentro da área de vida de um grupo de Sapajus nigritus numa área de Floresta Ombrófila Densa, localizada no Parque Estadual Carlos Botelho (PECB), Estado de São Paulo. Com o objetivo de descobrir se há ou não relação entre distribuição da vegetação arbórea com o padrão de uso da área (relacionadas com as rotas realizadas em 2007) pelo grupo deSapajus nigritus. Com o auxílio de uma imagem do IBGE de 1:50.000 da área do PECB, cedido pelo Instituto Florestal, em São Paulo, foi feito um recorte da área de vida do grupo no software ArcView 9.3 para seleção duas áreas; a primeira conhecida como área central (ou área núcleo) onde o grupo utiliza com mais frequência, foi denominada de área A, e a segunda área, uma pequena porção mais periférica da área de vida com inclinação mais acentuada, denominada de área B. Em cada uma dessas áreas foram instaladas três unidades amostrais; uma em área de topo de morro, uma em área de encosta e uma em área de fundo de vale, totalizando seis unidades amostras (G1, G2, G3, G4, G5 e G6). Cada unidade amostral, contendo quatro parcelas de 20 x 20 m (400 m2), espaçadas de 40 m e 60 m e subdivididas em subparcelas de 5 x 5 m (25 m2), totalizando 24 parcelas e 384 subparcelas, perfazendo uma área de 9.600 m2. O critério de inclusão foi DAP (diâmetro à altura do peito) 10 cm. Os resultados florísticos amostraram 672 indivíduos pertencentes a 146 espécies e 84 famílias (levando em conta os indivíduos não identificados e os mortos). As famílias que apresentaram maior riqueza de espécies foram respectivamente, Myrtaceae, Lauraceae e Fabaceae para todas as unidades amostrais. Das 146 espécies amostradas, 70 são espécies utilizadas pelo grupo de Sapajus nigritus como alimento, dentre elas, 43 (a maioria) estão amostradas em ambas as áreas e estão distribuídas na menor classe diamétrica.Quanto a fitossociologia, as espécies com maior valor no índice de importância (IVI) foram: Ocotea catharinensis (Canela-preta) para as grades amostrais em áreas de topo de morro e encosta, e Alchornea triplinervia (Tapiá) para as grades amostrais em áreas de fundo de vale. Os resultados indicaram que a composição fitossociológica da vegetação das parcelas amostradas em diferentes situações de topografia, não apresentou relação com o padrão de ocupação da área pelo grupo de macacos-prego, pois as espécies arbóreas estão amostradas em ambas as áreas de maneira homogênea. O fato de o grupo utilizar com mais frequência a área central da área de vida não está relacionado com a distribuição da vegetação e nem com as feições topográficas, mas sim pode estar relacionada a outros fatores, como a disponibilidade de frutos, variação sazonal, proteção contra predadores e outros fatores comportamentais. / Despite efforts in conducting research with primates in the Atlantic, there are still few studies topography, composition and distribution of vegetation with the pattern of occupation of the area by primates. Scarcity of such research, these relationships were analyzed in two areas within the home range of a group of Sapajus nigritus an area of dense rain forest, located in the Parque Estadual Carlos Botelho (PECB), State of Sao Paulo. Aiming to discover whether there is relationship between the distribution of trees with the usage pattern of the area (related to the routes taken in 2007) by the group Sapajus nigritus. With the aid of an image of the IBGE of 1:50.000 area PECB, assigned by the Forestry Institute, in São Paulo, a cut was made in the area of group life in ArcView 9.3 for selecting two areas, the first area known as central area (or core area) - where the group frequently used, was called area A, and the second area, a small portion of the peripheral area of life - with steepest slope, called Area B. In each of these areas were installed three sample units, one on top of the hill area, one in the hilly area and a background area in the valley, totaling six units strains (G1, G2, G3, G4, G5 and G6) . Each sample unit, containing four plots of 20 x 20 m (400 m2), spaced 40 m 60 m divided into subplots of 5 x 5 m (25 m2), totaling 24 plots and 384 plots, totaling an area of 9,600 m2. The inclusion criterion was DBH (diameter at breast height) 10 cm. The results floristic sampled 672 individuals belonging to 146 species and 84 families (taking into account the unidentified individuals and the dead). The families with the highest species richness were respectively Myrtaceae, Lauraceae and Fabaceae for all sample units. Of the 146 sampled species, 70 species are used by the group Sapajus nigritus as food, among them, 43 (the majority) are sampled in both areas and are distributed in the smallest diameter class. As for phytosociology, the species with the highest importance index (IVI) were: Ocotea catharinensis (Shin-black) for the sampling grids in areas of hill top and slope, and Alchornea triplinervia (Tapia) for the sampling grids in areas the valley bottom. The results indicated that the composition of phytosociological vegetation plots sampled in different situations topography was not related to the pattern of occupation of the area by the group of capuchin monkeys, because the tree species are sampled in both areas evenly. The fact that the group used more often to the central area of life is not related to the distribution of vegetation and with no topographic features, but may be related to other factors such as the availability of fruits, seasonal variation, protection against predators and other behavioral factors.

Submitted by CARLA MARIA GOULART DE MORAES (carlagm) on 2015-05-07T14:18:15Z No. of bitstreams: 1 EriveltonTomazzoniGoncalves.pdf: 514129 bytes, checksum: 16d68cb85838c6e25971df9dbe3e7cf1 (MD5) / Made available in DSpace on 2015-05-07T14:18:15Z (GMT). No. of bitstreams: 1 EriveltonTomazzoniGoncalves.pdf: 514129 bytes, checksum: 16d68cb85838c6e25971df9dbe3e7cf1 (MD5) Previous issue date: 2011 / Nenhuma / A variação espacial da abundância das espécies pode ser determinada por uma série de causas históricas e ambientais. Visando a identificação de grupos florísticos e a sua relação com um conjunto de variáveis edáficas e climáticas (ambientais), do espaço geográfico (histórico) na estruturação da composição arbórea ao longo de formações ombrófilas e estacionais do extremo sul do bioma Mata Atlântica-Brasil, extraiu-se da literatura dados de composição e abundância da flora arbórea (Dap >9.5 cm), de 52 unidades amostrais com cerca de 1 ha de extensão. As comunidades foram caracterizadas através de sete variáveis climáticas, nove variáveis edáficas, três estruturais, além da diversidade Jost, altitude e suas coordenadas geográficas. Análises de ordenação foram empregadas para síntese dos descritores edafo-climáticos e características estruturais (PCA), na estruturação florística entre as parcelas (NMDS) e posterior correlação com os fatores ambientais. Através de análise de agrupamento hierárquico identificou-se grupos florísticos com utilização de espécies indicadoras, as quais foram classificadas quanto aos seus corredores migratórios. Com o uso do teste G, avaliou-se a independência das rotas históricas de dispersão com a composição das espécies indicadoras dos grupos florísticos. Fatores relacionados ao nicho das espécies, como a temperatura, precipitação total e secundariamente a drenagem, fertilidade e profundidade do solo são consistentes com a distribuição da composição arbórea. Do mesmo modo a longitude configurou-se um forte preditor desta variação florística formando um gradiente ao longo dos corredores de dispersão tropicais, bem como os grupos florísticos obtidos apresentaram espécies indicadoras dependentes dos seus contingentes de origem. Identificou-se um gradiente estrutural de variação de área basal, altura média e densidade entre Florestas Ombrófilas Mistas e Florestas Estacionais, ao contrário da diversidade. Os grupos florestais exibem diferentes graus de separação entre si. As Florestas Estacionais e a Floresta Ombrófila Densa formam um gradiente florístico contínuo ao longo de dois corredores migratórios de modo a consistir um bloco único. A Floresta Ombrófila Mista constitui um grupo dissimilar a estas formações com uma subdivisão marcada por espécies indicadoras exclusivas. Fatores ambientais e históricos são responsáveis tanto pela divisão entre grupos, que podem ser de forma abrupta ou gradativa, quanto pela diferenciação interna destas formações. / The spatial variation of species abundance can be determined by a series of historical and environmental causes. In order to identify floristic groups and their relationship to a set of soil and climatic variables (environmental), the geographic area (historical) in structuring the composition of trees along formations and seasonal rainforests from southern Atlantic forest, Brazil drew from the literature data on the composition and abundance of tree flora (DBH> 9.5 cm) of 52 sample units with about 1 ha in extension. The communities were characterized using seven climate, nine soil and three structural variables, as well as the Jost diversity, altitude and geographic coordinates. Ordination analysis were employed for the synthesis of soil, climatic and structural descriptors (PCA), the floristic structure between plots (NMDS) and subsequent correlation with environmental factors. Through hierarchical cluster analysis identified himself with floristic groups using indicator species, which were classified according to their migratory corridors. By using the G test, we evaluate the independence between the historic routes of dispersion and the composition of indicator species groups. Factors related to the niche of the species, such as temperature, total precipitation, and secondarily drainage, fertility and soil depth, are consistent with the distribution of the composition tree. Likewise the longitude is a strong predictor of floristic variation forming a gradient along the corridors of dispersal tropical flora, and the groups obtained were dependent indicator species of origin of their contingents Unlike the diversity, it was identified a structural gradient of basal area variation, average height and density between Araucaria forest and seasonal forests,. The forestry groups exhibit different degrees of separation between themselves. Seasonal forests and form a dense rain forest floristic gradient along two continuous migration corridors in order to consist a single block. The Araucaria forest is a group dissimilar to these formations with a subdivision marked by unique indicator species. Environmental and historical factors are responsible for both, the division between groups that may be abrupt or gradual, as well as the internal differentiation of these formations.

RESUME Les données phytogéographiques reflètent la variabilité spatiale de la diversité des espèces et constituent donc un outil important dans le développement des politiques de conservation. Afin de stimuler et de valoriser le concept des systèmes phytogéographiques, cette étude dont le thème est «Analyse des structures spatiales des données de distribution phytogéographique des Acanthaceae en Afrique centrale» s’est donnée pour but (1) d’analyser la distribution spatiale de la famille des Acanthaceae en Afrique Centrale (R.D. Congo, Rwanda, Burundi) ; (2) de comparer cette distribution avec les théories phytogéographiques de Robyns (1948), White (1979, 1986) et Ndjele (1988); (3) d’utiliser les modèles de distribution spatiale comme support (outil) pour évaluer l'impact humain sur le paysage et la diversité; (4) d’identifier les espèces indicatrices potentielles des territoires phytogéographiques; (5) de mettre en évidence le phénomène de vicariance; et (6) de quantifier l’impact de la fragmentation du paysage forestier en Afrique centrale. Dans cette étude, deux niveaux de résolution spatiale ont été considérés: les systèmes phytogéographiques et les systèmes de maillage. Un système d’information géographique a été utilisé pour réaliser des cartes de distribution spatiale de chaque espèce. Le choix des Acanthaceae de l’herbier du Jardin Botanique National de Belgique (BR), a été dicté par le faite qu’elle a subit une révision systématique et par le nombre important de ses échantillons. L’aspect floristique a révélé 9181 échantillons, récoltés de 1888 à 2001 par environ 427 collecteurs en R.D. Congo, au Rwanda et au Burundi représentant 48 genres, 310 espèces et 6362 localités. La carte de distribution spatiale de l’ensemble des échantillons a mis en évidence les niveaux de prospection. Certains territoires phytogéographiques ont été plus explorés que d’autres. Les entités phytogéographiques les plus explorées et donc les plus diversifiées sont le centre régional d’endémisme Afromontagnard, incluant la Mosaïque régional du lac Victoria, et le centre régional d’endémisme Zambézien. Les cartes de distribution de chaque espèce mettent en évidence les patrons de distribution spatiale. Certaines espèces ont une large distribution alors que d’autres sont inféodées à certaines zones spécifiques. Ces dernières, qualifiées « d’espèces uniques » ou « espèces caractéristiques » peuvent être utilisées comme des bio-indicateurs pour stimuler et valoriser le concept de systèmes phytogéographiques dans la politique de la conservation. En utilisant uniquement la famille des Acanthaceae, il a été montré que l’impact de la fragmentation du paysage forestier est très important. Les espèces inféodées à une région phytogéographique sont des espèces vulnérables. Elles peuvent disparaître si leur biotope est détruit. La distribution potentielle, basées sur les localités de récolte et les variables environnementales, ont été réalisées afin de mieux déterminer les niches écologiques des espèces et les cas de vicariance. Deux types de vicariance ont été mis en évidence à travers les systèmes phytogéographiques de Robyns (1948) et de White (1979, 1986), au niveau générique et spécifique: la vicariance écologique et la vicariance géographique. La vicariance écologique s’applique aux espèces ou sous-espèces récoltées dans les mêmes territoires phytogéographiques tandis que la vicariance géographique concerne les espèces ou sous-espèces récoltées dans des territoires phytogéographiques séparés. L’analyse des cas de vicariance a mis en relief les zones de spéciation. L'analyse de classification hiérarchique a montré que les Acanthaceae suivent mieux le système phytogéographique de White (1979, 1986) que ceux proposés par Robyns (1948) et Ndjele (1988). Pour mieux valoriser cette approche, cette méthodologie doit être appliquée à d’autres familles largement récoltée en R.D. Congo, au Rwanda et au Burundi comme la famille des Rubiaceae, des Mimosoideae, afin de (1) synchroniser toutes les bases de données pour mieux mettre en évidence le degré d’exploration, les espèces à amplitude écologique restreinte (espèces uniques) et (2) de permettre d’identifier des zones prioritaires pour la conservation. ABSTRACT Phytogeographic data reflect the spatial variability of plant diversity and constitute consequently a potential tool for conservation policy development. In order to stimulate and valorise the concept of phytogeographic systems, this dissertation entitled “Analysis of the spatial pattern of phytogeographic data of Acanthaceae in Central Africa” aims (1) to analyse the spatial distribution of the Acanthaceae family in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi); (2) to compare this distribution with the known phytogeographic theories of Robyns (1948), White (1979, 1986) and Ndjele (1988); (3) to use the spatial distribution models as a tool for evaluating the human impact on landscapes and diversity; (4) to identify potential indicator species of the phytogeographic territories; (5) to evidence the phenomenon of vicariance; and (6) to quantify the impact of the fragmentation of forested landscapes in central Africa. In this study, two levels of spatial resolution have been considered: the phytogeographic systems themselves and a system of grid cells. A geographic information system has been used to draw maps of the spatial distribution of every species. The choice to analyse the Acanthaceae family of the herbarium of the National Botanical Garden of Belgium (BR) has been justified by the systematic revision of this collection and by its huge number of samples. The data set contained 9181 samples, collected between 1888 and 2001 by about 427 collectors in the Democratic Republic of the Congo, Rwanda and Burundi ; the samples represented 48 genera, 310 species and 6362 geographic positions. The maps showing the spatial distribution of all samples pooled evidenced the different levels of exploration of the study area. Certain phytogeographic territories have been explored more intensely than others. The mostly explored zones, consequently also denoted as the most diverse ones, were the Afromontane regional centre of endemism, including the regional mosaic of Lake Victoria, and the Zambezian regional center of endemism. Species distribution maps evidenced the spatial patterns of species presence. Certain species showed an overall distribution while others were clearly bound to particular territories. The latter species, denoted as “unique species” or “characteristic species” could be used as bio-indicators to stimulate and valorise the concept of the phytogeographic systems in the framework of conservation policy development. By means of the Acanthaceae family, it has been shown that the impact of forest fragmentation will be considerable; species bound to a specific phytogeographic zone are assumed vulnerable; they will disappear when their biotopes are destroyed. The potential distribution of the species, based on the geographic position of the samples and on environmental data, have been generated in order to describe more precisely the ecological niches of the species involved and to detect cases of vicariance. Two types of vicariance have been found using the phytogeographic territories of Robyns (1948) and White (1979, 1986) at the genus and the species levels: ecological vicariance and geographic vicariance; the former type involves species or subspecies observed in the same phytogeographic region while the latter type involves species and subspecies not found in the same territory. This analysis enabled us to identify zones of speciation. A cluster analyses showed that the spatial distribution of the Acanthaceae data corresponded more closely to the phytogeographic system of White (1979, 1986), than to those proposed by Robyns (1948) or Ndjele (1988). In order to valorise our approach, the current methodology should also be applied to other families widely collected in the Democratic Republic of the Congo, Rwanda and Burundi, such as the Rubiaceae or Mimosoideae families, this (1) to synchronise all data bases for a more profound understanding of the degree of exploration and of the existence of species with a limited ecological amplitude (unique species), and (2) to enable the identification of zones that should be prioritised for conservation.

L’Afrique centrale atlantique (ACA) englobe l’ensemble du domaine bas-guinéen, les îles du Golfe de Guinée et une partie de l’archipel afromontagnard. Plusieurs centres d’endémisme ont été identifiés en son sein et sont généralement considérés comme liés à la présence de refuges forestiers durant les périodes glaciaires. Cependant, l’origine de cet endémisme, sa localisation et les méthodes permettant d’identifier ces centres restent controversées. La localisation de ces zones d’endémisme et des plantes rares qu’elles abritent, est pourtant un prérequis indispensable pour la mise en place de politiques cohérentes de conservation et demeure une priorité pour les organisations privées, institutionnelles ou gouvernementales actives dans la gestion et le maintien durable de la biodiversité. Cette étude phytogéographique porte sur la famille des Orchidaceae et est basée sur l’analyse de la distribution des taxons endémiques de l’ACA. Elle s’appuie sur un jeu de données original résultant d’un effort d’échantillonnage important au Cameroun et d’un travail d’identification et de localisation de spécimens dans les principaux herbaria européens abritant des collections d’ACA. Durant cette étude, (i) nous avons tout d’abord identifié ces taxons endémiques et documenté leur distribution au travers de plusieurs contributions taxonomiques et floristiques, (ii) nous nous sommes ensuite intéressé aux nouvelles méthodes permettant d’analyser ces données d’herbier de plantes rares et donc pauvrement documentées, testant aussi l’intérêt des Orchidaceae comme marqueurs chorologiques, et finalement, appliquant ces méthodes à notre jeu de données, (iii) nous avons délimité des centres d’endémisme et identifié les territoires phytogéographiques des Orchidaceae en ACA. (i) Une révision taxonomique des genres Chamaeangis Schltr. et Stolzia Schltr. a été réalisée respectivement. Sept nouveaux taxons ont été décrits: Angraecum atlanticum Stévart & Droissart, Chamaeangis spiralis Stévart & Droissart, Chamaeangis lecomtei (Finet) Schltr. var. tenuicalcar Stévart & Droissart, Polystachya engogensis Stévart & Droissart, Polystachya reticulata Stévart & Droissart, Stolzia repens (Rolfe) Summerh var. cleistogama Stévart, Droissart & Simo et Stolzia grandiflora P.J.Cribb subsp. lejolyana Stévart, Droissart & Simo. Plusieurs notes taxonomiques, phytogéographiques et écologiques supplémentaires ont également été redigées. Au total, nous avons identifié 203 taxons d’Orchidaceae endémiques d’ACA parmi lesquels 193 sont pris en compte pour l’étude des patrons d’endémisme. (ii) Au Cameroun, les patrons de distribution des Orchidaceae et des Rubiaceae endémiques d’ACA ont été étudiés conjointement. Des méthodes de rééchantillonnage des données (raréfaction) ont été appliquées pour calculer des indices de diversité et de similarité. Elles ont permis de corriger les biais liés à la variation de l’effort d’échantillonnage. Un gradient de continentalité a été observé, les parties côtières étant les plus riches en taxons endémiques d’ACA. Contrairement à la région du Mont Cameroun et aux massifs de Kupe/Bakossi qui ont connu une attention particulière des politiques et des scientifiques, la partie côtière du sud Cameroun, presque aussi riche, reste mal inventoriée pour plusieurs familles végétales. Cette analyse à l’échelle du Cameroun a également permis de comparer les patrons d’endémisme des Orchidaceae et des Rubiaceae. Les différences observées seraient principalement dues à la présence d’Orchidaceae terrestres dans les végétations basses et les prairies montagnardes de la dorsale camerounaise alors que les Rubiaceae sont généralement peu représentées dans ces habitats. Au sein des habitats forestiers, la concordance entre les patrons d’endémisme des Orchidaceae et des Rubiaceae remet en question l’utilisation des capacités de dispersion des espèces comme critère pour choisir les familles permettant l’identification des refuges forestiers et semble ainsi confirmer la pertinence de l’utilisation des Orchidaceae comme marqueur chorologique. La distribution potentielle a été utilisée pour étudier en détail l’écologie, la distribution et le statut de conservation de Diceratostele gabonensis Summerh., une Orchidaceae endémique de la région guinéo-congolaise uniquement connue d’un faible nombre d’échantillons. Cette méthodologie semble appropriée pour compléter nos connaissances sur la distribution des espèces rares et guider les futurs inventaires en Afrique tropicale. (iii) En ACA, les Orchidaceae permettent d’identifier plusieurs centres d’endémisme qui coïncident généralement avec ceux identifiés précédemment pour d’autres familles végétales. Ces constats supportent aussi l’utilisation des Orchidaceae comme marqueur chorologique. La délimitation des aires d’endémisme des Orchidaceae a ainsi permis de proposer une nouvelle carte phytogéographique de l’ACA. Les éléments phytogéographiques propres à chacune des dix phytochories décrites ont été identifiés et leurs affinités floristiques discutées. Les résultats phytogéographiques obtenus (a) soutiennent l’existence d’une barrière phytogéographique matérialisée par la rivière Sanaga entre les deux principaux centres et aires d’endémisme de l’ACA, (b) étendent l’archipel afromontagnard situé principalement au Cameroun au plateau de Jos (Nigeria) et (c) montrent l’importance de la chaîne montagneuse morcelée Ngovayang-Mayombe pour la distribution de l’endémisme en ACA. Cette chaîne de montagne, qui s’étend le long des côtes de l’océan du sud Cameroun au Congo-Brazzaville et qui correspond à plusieurs refuges forestiers identifiés par de nombreux auteurs, est ici considérée comme une seule aire d’endémisme morcelée./ Atlantic central Africa (ACA) covers the Lower Guinean Domain, the four islands of the Gulf of Guinea and a part of the afromontane archipelago. Different centres of endemism have been identified into this area and are usually considered as related to glacial forest refuges. However, the origin of this endemism, the localization of the centres and the methods employed to identify these centres are subject to debate. Yet, the localization of these centres of endemism and the identification of the rare plants they harbor is an essential prerequisite to setting up rational conservation policies, and remains a priority for private, institutional and governmental organizations which are dealing with the sustainable management of biodiversity. This phytogeographical study focuses on Orchidaceae and analyses the distribution of the taxa endemic to ACA. We use an original dataset resulting from an important sampling efforts and the identification of specimens coming from all the principal herbaria where collections from ACA are housed. During this study, (i) we first identified the taxa endemic to ACA and documented their distribution through several taxonomic and floristic contributions, (ii) we used and developed new methods allowing to correct for sampling bias associated with the use of rare and poorly documented taxa, testing at the same time the use of Orchidaceae as chorological markers, and finally, applying these methods to our dataset, (iii) we delimited the centres of endemism and identified the phytogeographical territories of Orchidaceae in ACA. (i) A taxonomic revision of Chamaeangis Schltr. and Stolzia Schltr. respectively was carried out. Seven new taxa were described: Angraecum atlanticum Stévart & Droissart, Chamaeangis spiralis Stévart & Droissart, Chamaeangis lecomtei (Finet) Schltr. var. tenuicalcar Stévart & Droissart, Polystachya engogensis Stévart & Droissart, Polystachya reticulata Stévart & Droissart, Stolzia repens (Rolfe) Summerh var. cleistogama Stévart, Droissart & Simo and Stolzia grandiflora P.J.Cribb subsp. lejolyana Stévart, Droissart & Simo. Several additional taxonomic, phytogeographical and ecological notes were also published. We finally identified 203 Orchidaceae taxa endemic to ACA, among which 193 were used to study the patterns of endemism. (ii) In Cameroon, the distribution patterns of both Orchidaceae and Rubiaceae endemic to ACA were studied. Subsampling methods (rarefaction) were applied to calculate diversity and similarity indices and to correct potential bias associated with heterogeneous sampling intensity. A gradient of continentality was confirmed in Cameroon, the coastal part being the richest in taxa endemic to ACA. The Cameroon Mountain and the Kupe/Bakossi mountain massifs have received a great consideration of politics and scientists. On the contrary, the Southern coastal part of Cameroon, though almost as rich as the Northern part, remains poorly known for several plant families. This analysis also allowed us to compare patterns of endemism of Orchidaceae and Rubiaceae. The differences observed could be mainly due to the terrestrial habit of some Orchidaceae, which are only found in the grasslands of the highest part of the Cameroonian volcanic line where endemic Rubiaceae are rare. Within forest habitats, the concordance between the patterns of endemism of Orchidaceae and Rubiaceae question the widespread use of dispersal ability as a selection criterion for the families used to identify forest refuges. This also confirms the relevance of Orchidaceae as chorological marker. Species distribution modelling was used of an in depth study of the ecology, the distribution and the conservation status of Diceratostele gabonensis Summerh., an Orchidaceae endemic to the Guineo-Congolian regional centre of endemism which is only known from very few collections. This method is proved to be appropriate to complete our knowledge on the distribution of rare plant species and to guide the future inventories in tropical Africa. (iii) In ACA, an analysis of the distribution of endemic Orchidaceae confirmed the presence and location of several centres of endemism previously identified on the basis of other plant families. This result again supports the use of Orchidaceae as a chorological marker. The chorological study of the endemic Orchidaceae allowed us to propose a new phytogeographical map for ACA. Phytogeographical elements for each of the ten phytochoria described were identified and their floristic affinities were also discussed. Our results (a) support the existence of a phytogeographical barrier, materialized by the Sanaga River, between the two main centres and area of endemism of the ACA, (b) extend the limits of the afromontane archipelago to the Jos Plateau in Nigeria and (c) show the importance of the Ngovayang-Mayombe line to explain the distribution of endemism in ACA. This mountainous line, stretching along the ocean coast from Southern Cameroon to Congo-Brazzaville, corresponds to several forest refuges identified by many authors, and is here considered as an unique but discontinuous area of endemism.

Climatic oscillation during the Quaternary resulted in fragmentation of once more continuous ancient floras and a series of invasions of different floras into the Pondoland Centre in response to climatic change, with some elements invading more than once. This implies both a temporally complex and a floristically complex origin for the extant flora of the Centre. Data derived from analysis of the melange of extant floristic elements in the Pondoland Centre is presented in support of this hypothesis. A synfloristic comparison of Oribi Gorge (OGNR) and Umtamvuna Nature Reserves (UNR) is the basis for this study. A comparison of the species lists generated for OGNR and UNR reveals that 24% of the 1514 angiosperm species are shared. The familial composition of the reserves is similar, with eight of the ten most diverse families contributing a similar proportion of species to the respective floras, with the exception of Acanthaceae. The ten most diverse families comprise a comparatively small proportion of the respective floras; this is indicative of high diversity over long geological periods, i.e. of refugia. Analysis at the generic level revealed similar consistancy between the two gorge floras. Approximately 4% of the UNR species and 2.3% of OGNR species are Pondoland Centre endemics. Approximately 40% of the endemic species are shared by the gorges. Data reveals that both palaeoendemic (predominantly woody, forest taxa) and neoendemic (predominantly herbaceous or suffrutescent, grassland taxa) species occur. The Pondoland Centre is thus a refugium for species trapped on the Msikaba Group sandstones as a result of climatic oscillation during the Quaternary, and a centre of neoendemism. OGNR and UNR floras include Cape, Afromontane and tropical elements (11.3%, 2.8% and 19.1% respectively for OGNR and 16%,3.4% and 15.3% respectively for UNR). Seventy - two percent of Afromontane species are shared, indicating a relatively recent invasion(s) and lor the relative proximity of the gorges to the Afromontane flora. The lower species overlap in the Cape element (39.2%) of the two gorges implies that the invasion of the element is ancient, with subsequent extinction of many of the taxa from OGNR in response to climatic change. It is also possible that this invasion was initally less successful; fewer species found refuge in OGNR. The tropical element comprises the largest proportion of the flora in both gorges and many (ca. 50%) of the species are shared. The degree of species overlap indicates that the invasive flora was either initially more similar or that it is tess prone to extinction. The level of overlap could also suggest that the invasion was more recent than that of the Cape taxa. The tropical element is larger in OGNR and the Cape element is larger in UNR. This is partly due to the gorges' respective proximities to the tropical and Cape floras. This trend is echoed in the endemic data. iv The conservation status of the endemics and of the Pondoland vegetation types is established and recommendations for further research are made. The data support the establishment of a larger UNR, the maintenance of both Umtamvuna and Oribi Gorge as formal nature reserves and the establishment of a new reserve (or reserves) within the Pondoland Centre. / Thesis (M.Sc.)-University of Natal, Pietermarizburg, 1998.

The purpose of this study was to describe the composition, structure and spatial distribution of plant communities at Wilbur Wright Fish and Wildlife Area (WWFWA) in order to provide baseline information to which future conditions can be compared. The plant communities of WWFWA were delineated, sampled, and subsequently classified using the framework of the National Vegetation Classification System. Data were collected for three strata of vegetation: overstory, understory and groundcover. Five permanent plots were established in the forested communities to monitor changes in vegetation over time.Eleven general habitat types were described for WWFWA. Plant communities varied from highly diverse mature woods to successional communities dominated by exotic vegetation. The composition and structure of plant communities appears to be closely related to previous land-use. Management practices are recommended in order to improve the condition of depauperate plant communities and to maintain the integrity of native plant communities. / Department of Biology

In this study, geographic information systems (GIS) and remote sensing (RS) tools were integrated and used to investigate the plant species diversity of the Nallihan forest ecosystem. Two distinct indices, Shannon Wiener and Simpson, were employed in order to express species diversity. The relationships between the indices and pertinent independent variables (topography, geology, soil, climate, supervised classes, and Normalized Difference Vegetation Index (NDVI) classes) were investigated to develop two distinct models for each index. After detecting important components with factor analysis, two models were developed by using multiple regression statistics. Running the models, two plant species diversity maps in grid format were produced. The validity of the models were tested by (1) mapping residuals to predict the locations where the models work perfectly, and (2) logical interpretations in ecological point of view. Elevation and climatic factors formed the most important component that are effective on plant species diversity. Geological formations, soil, land cover and land-use characteristics were also found influential for both models. Considering the disturbance and potential evapotranspiration (PET), the model developed for Shannon Wiener index was found out more suitable comparing the model for Simpson index.