A phytosociological study covering approximately 12 000 km2 was completed within Southeastern Mpumalanga high altitude grasslands. The towns of Belfast, Barberton, Piet Retief and Wakkerstroom represented the four corners of the area. The study formed part of the Grassland Biome Project sponsored by the Department of Environmental Affairs and Tourism. The Braun-Blanquet approach was applied. Grassland research results from the western side of the country, determined that soil patterns and vegetation distribution are significantly correlated. Based on these results, it was hypothesised that the same correlation would exist in the east. The eight soil patterns used during the survey as homogenous units, were Ab, Ac, Ad, Ae, Ea, Fa, Fb and lb. A pro rata, randomly stratified sample size of 405 plots were used. An in-depth literature study of the environmental and other factors related to vegetation distribution, indicated on local scale that a significant correlation exists between landform and plant distribution. Two geographic information systems, Idrisi and Arc-Info/Niew, aided in the modelling and extraction of environmental attributes from existing databases. A TWINSPAN classification of the complete floristic data set falsified the null hypothesis based on the soil patterns but verified the null hypothesis based on landforms. The TWINSPAN dendrogram revealed clusters associated with three landforms (mountains, hills and lowlands, and plains) in two ecosystems, the terrestrial and the wetlands or aquatic. The three landforms represented three mapping units: Southeastern Mpumalanga Mountain Vegetation Type, Southeastern Mpumalanga Hills and Lowland Vegetation Type and Southeastern Mpumalanga Plain Vegetation Type. A second TWINSPAN classification was executed on each of the vegetation types. The resulting clusters were tested for uniqueness and informational value using a set of criteria. Those clusters which qualified were arranged in a Braun-Blanquet table to determine communities, sub-communities and variations using constancy and fidelity values. The plant communities within the vegetation types were described in terms of floristic composition and environmental attributes. The indirect gradient analysis ordination program DECORANA was used to determine environmental trends and was confirmed by using multiple regression. Soil water availability was the most significant environmental trend between the two ecosystems and within the communities of the ecosystems in each vegetation type. Soil water availability is influenced by numerous factors, whose significance differs from one vegetation type to another. lt was concluded from this study that, in high rainfall areas, soil patterns and vegetation distribution are not significantly correlated but that landforms and vegetation distribution are significantly correlated. Landscape slope configuration or landform influences soil water availability through soil characteristics (rockiness, texture and depth) and local climatic conditions (aspect, perpendicular insolation and precipitation). lt is suggested that the current Grassland - Savanna Biome boundary be changed towards the west using the boundary between the covered and exposed shields. This suggestion is supported by the presence of Hyparrhenia hirta/Hyperthelia dissoluta - Acacia sieberiana communities to the east of the study area in the different vegetation types which correlate significantly with the thorntree-tall grass savanna formation on a global scale. AFRIKAANS : 'n Fitososiologiese studie is gedoen van die Suid-oostelike Mpumalanga hoe liggende grasveld tussen die dorpe Belfast, Barberton, Piet Retief en Wakkerstroom. 'n Area van ongeveer 12 000 km2 is bestudeer. Die studie is deel van die Grasveld Bioom Projek gefinansier deur die Departement van Omgewingsake en Toerisme. Die Braun-Blanquet benadering is gebruik. Resultate van grasveldnavorsing in die westelike deel van die grasveld bioom, het aangedui dat 'n betekenisvolle verband tussen grondpatrone en plantegroei verspreiding bestaan. Na aanleiding van hierdie resultate, is die hipotese gemaak dat dieselfde verband in die ooste sal voorkom. Agt grondpatrone, Ab, Ac, Ad, Ae, Fa, Fb, en lb is as homogene eenhede beskou. 'n Eweredige ewekansige steekproefneming van 405 punte is gebruik. 'n Deeglike literatuurstudie van die omgewing en faktore wat verband hou met plantegroei verspreiding, het aangedui op lokale skale, dat 'n verband tussen landvorm en plantegroei verspreiding bestaan. Twee geografiese inligtingstelsels, ldrisi en Arc-lnfo/View, is gebruik in die modelering en verkryging van omgewings data vanuit bestaande databasisse. 'n TWINSPAN klassifikasie gebaseer op die volledige spesiesamestelling, het die nul hipotese oor die grondpatrone ongeldig verklaar maar die nul hipotese oor die landvorme bevestig. Die TWINSPAN dendrogram het groeperings bevat wat verband hou met drie landvorme (berge, heuwels en laaglande en vlaktes) in twee ekosisteme, terrestrieel en vleiland van akwatiese omgewings. Die drie landvorme is beskou as drie karteerbare eenhede: Suid-oostelike Mpumalanga Berg Plantegroeitipe, Suidoostelike Mpumalanga Heuwels en Laagland Plantegroeitipe en Suid-oostelike Mpumalanga Vlakte Plantegroeitipe. 'n Tweede TWINSPAN klassifikasie is op elk van die plantegroeitipes toegepas. Elke plantegroeitipe se groeperings is met behulp van bepaalde voorwaardes vir uniekheid en inligtingswaarde getoets. Die groeperings wat gekwalifiseer het, is met behulp van konstantheids en getrouheids waardes in 'n Braun-Blanquet tabel gerangskik in gemeenskappe, sub-gemeenskappe en variasies. Elke plantegroei tipe se gemeenskappe is beskryf in terme van floristies spesiesamestelling en omgewingsfaktore. 'n indirekte gradientanalise ordeningsprogram DECORANA is gebruik vir die bepaling van omgewings tendense en is bevestig met behulp van veelvuldige regressies. Grondwaterbeskikbaarheid was die mees betekenisvolle omgewingstendens tussen die ekosisteme en die gemeenskappe van die plantegroei tipes. Grondwaterbeskikbaarheid word deur 'n aantal faktore beïnvloed, waarvan die belangrikheid van plantegroei tipe tot plantegroeitipe wissel. 'n Gevolgtrekking van die studie is, dat in hoë reënvalomgewings daar nie 'n betekenisvolle verband is tussen grondpatrone en plantegroei verspreiding nie maar wel tussen landvorme en plantegroeiverspreiding. Landskap hellingsamestelling of landvorme beïnvloed grondwaterbeskikbaarheid deur middel van grondeienskappe (klipperigheid, tekstuur en diepte) en lokale klimaatstoestande (aspek, loodregte bestraling en presipitasie). Daar word voorgestel dat die huidige Grasveld- Savanna Bioom grens weswaarts geskuif word om ooreen te stem met die grens tussen die bedekte en blootgestelde plate. Die voorstel word ondersteun deur die teenwoordigheid van Hyparrhenia hirta/Hyperthelia dissoluta - Acacia sieberana plantgemeenskappe in die ooste van die plantegroeitipes wat betekenisvol ooreenstem met die langgras-doring boom savanna formasie op globale skaal. / Dissertation (MSc)--University of Pretoria, 1999. / Plant Science / unrestricted

Orientador: Rafael Silva Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-20T07:23:50Z (GMT). No. of bitstreams: 1 DiMigueli_CaioOliveira_M.pdf: 2747069 bytes, checksum: d9c9a266d54797dc0c2753c7d1a10446 (MD5) Previous issue date: 2012 / Resumo: A disponibilidade de água é um importante fator determinante da distribuição de espécies vegetais em várias comunidades. Vários modelos climáticos preveem secas mais severas para regiões tropicais de altitude em decorrência do aumento na altitude média das camadas de nuvens orográficas que dão origem à neblina, o que poderá afetar a distribuição de espécies e de tipos vegetacionais da Floresta Atlântica nesses locais. Investiguei a diversidade de atributos hidráulicos de seis espécies de Floresta Nebular e quatro espécies de Campos de Altitude com o objetivo de entender as respostas de espécies desse tipo de vegetação a variações sazonais na disponibilidade de água. Optei por investigar atributos hidráulicos pois têm influência direta sobre as estratégias de uso de água pelas plantas em diferentes condições de disponibilidade desse recurso. Escolhi esses ecossistemas por co-ocorrerem em um topo de montanha e por apresentarem condições contrastantes quanto à seca ambiental, com diferentes níveis de exposição do solo às condições climáticas. Quantifiquei densidade da madeira, potenciais hídricos antes do amanhecer, às 10:00 h e mínimo diário e condutância estomática. Investiguei ainda a ocorrência nesses ecossistemas de relações negativas entre densidade da madeira e potenciais hídricos mínimos, já observadas em florestas tropicais secas e ambientes temperados. Verifiquei uma grande diversidade de valores de densidade da madeira nas espécies que estudei. As quatro espécies de Campos de Altitude apresentaram influência da demanda evaporativa da atmosfera sobre seus potenciais hídricos nos meses mais úmidos do estudo, o que é consistente com comportamento anisohídrico. Nesse tipo de estratégia, a condutância estomática se mantém inalterada frente a reduções nas disponibilidades de água do solo e da atmosfera, resultando em redução do potencial hídrico da planta. Nos meses mais secos essa influência foi menor, como se observa em plantas com comportamento isohídrico, que reduzem a condutância estomática e mantêm potenciais hídricos constantes frente ao aumento da seca ambiental. Dentre as espécies de floresta, apenas D. brasiliensis e Vernoniae sp. apresentaram comportamento isohídrico, as demais apresentaram comportamento anisohídrico. Com base nesses resultados faço a previsão que D. brasiliensis e Vernoniae sp. são as espécies mais vulneráveis à seca e podem apresentar maiores taxas de mortalidade por "privação de carbono", em decorrência do seu comportamento isohídrico. Em seguida, as espécies anisohídricas mais vulneráveis à seca são P. vellosiana, L. carassana e Miconia sp., em ordem decrescente de vulnerabilidade à cavitação. As espécies de Campos de Altitude são as mais resistentes à seca. A densidade da madeira só apresentou relação com o potencial hídrico mínimo sazonal quando analisei as espécies de Floresta Nebular e de Campos de Altitude em conjunto, e apresentou uma forte relação linear negativa com o potencial hídrico mínimo diário nas espécies de floresta. Esses resultados indicam que as relações entre esses atributos propostas na literatura parecem estar presentes nos ecossistemas que estudei / Abstract: Water availability is an important feature determining plant species distribution in several communities. Several climatic models predict harsher dry spells for high-altitude tropical regions due to the increase in the mean altitude of formation of the orographic cloud layer that originates fog, which can influence the distribution of species and vegetational types of the Atlantic Forest in these places. I have investigated the diversity of hydraulic traits of six Cloud Forest species and four High-altitude Grasslands species to understand the answers of species of this kind of vegetation to seasonal variations in water availability. I have choosen to investigate hydraulic traits because they have direct influence on the plant water use strategies under different conditions of availability of this resource. I have choosen these ecosystems because they co-occur in a mountain top and present contrasting conditions relative to environmental drought, with different exposure levels of the soil to climatic conditions. I have quantified wood density, pre-dawn, 10:00 o' clock and daily minimun water potentials and stomatal conductance. I have also investigated the occurrence in these ecosystems of negative relationships between wood density and minimun water potentials, that have been observed in tropical dry forests and in temperate environments. I found a very large diversity of wood density values in the species I have studied. The four High-altitude Grasslands species presented influence of atmospheric evaporative demand on their water potentials, consistent with anisohydric behaviour. In this strategy, stomatal conductance remains unaltered in face of reductions in soil and atmosphere water availabilities, resulting in reduction of plant water potential. In the wettest months this influence was smaller, as is seen in plants with isohydric behaviour, that reduce stomatal conductance and maintain constant water potentials in face of environmental drought intensification. Among the forest species, only D. brasiliensis and Vernoniae sp. presented isohydric behaviour, the remaining showing anisohydric behaviour. Based on these results I make the prediction that D. brasiliensis and Vernoniae sp. are the most drought vulnerable species and may present higher mortality rates by carbon starvation, due to their isohydric behaviour. Following these two species, the most drought vulnerable anisohydric species are P. vellosiana, L. carassana and Miconia sp., in decreasing order of vulnerability to cavitation. The High-altitude Grasslands species are the most resistant to drought. There was a correlation between wood density and minimun seasonal water potential only when I analised the Cloud Forest and the High-altitude grasslands species togheter. There was also a strong negative linear relationship between wood density and daily minimun water potential in the forest species. These results show that the relationships between these traits that are proposed in the literature appear to be present in the ecosystems I studied / Mestrado / Ecologia / Mestre em Ecologia

Orientador: George John Shepherd / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-14T22:19:27Z (GMT). No. of bitstreams: 1 Meireles_LeonardoDias_D.pdf: 52013493 bytes, checksum: d5034b3efafae60949067d81a6753f38 (MD5) Previous issue date: 2009 / Resumo: A Serra Fina é o nome de umas das áreas da Serra da Mantiqueira Meridional, uma cadeia montanhosa na divisa geográfica entre Minas Gerais, São Paulo e Rio de Janeiro, sudeste do Brasil. A Serra Fina compreende um dos maciços de rochas alcalinas que forma uma das áreas de maior altitude dessa região com mais de 2.500 metros de altitude em vários locais. Ela apresenta um destacado gradiente altitudinal que permite a ocorrência de diferentes formações vegetacionais altimontanas. Sua vegetação apresenta-se ainda relativamente conservada, mas pouquíssimo conhecida. Nós objetivamos analisar a composição florística de suas formações vegetacionais altimontanas, descrever a estrutura fitossociológica das florestas nebulares, verificar a similaridade dessa floresta com outras florestas montanas brasileiras e verificar como mudanças climáticas quaternárias influenciaram a distribuição geográfica das espécies que as compõem. Nos campos de altitude, matas de candeias e nas florestas nebulares foram coletadas 393 espécies das quais sete são provavelmente novas para a ciência. As famílias Asteraceae, Poaceae, Melastomataceae, Rubiaceae, Cyperaceae, Fabaceae, Myrtaceae, Orchidaceae e Ericaceae apresentaram as maiores riquezas específicas. Duas espécies novas da família Asteraceae restritas aos campos de altitude acima de 2.500 metros de altitude foram descritas e ilustradas e as demais necessitam de estudos detalhados por especialistas. A riqueza específica amostrada denota a importância das áreas de altitude na diversidade da Floresta Atlântica e denotam a importância fitogeográfica da Serra Fina por apresentar um grande número de espécies endêmicas ou com distribuição geográfica restrita e comportar espécies com fortes relações com a flora dos Andes, oeste da América do Sul. As florestas apresentaram características típicas de florestas nebulares como menor riqueza, elevada densidade e um dossel reduzido. Myrsinaceae, Myrtaceae, Symplocaceae e Cunoniaceae foram as famílias de maior valor de importância. As florestas alto-montanas da Serra da Mantiqueira apresentaram alta similaridade florística com florestas nebulares sulinas e em parte com as florestas alto-montanas do interior de Minas Gerais e do topo da Serra do Mar em São Paulo, que apresentam uma composição florística relativamente diferenciada. A similaridade dessas florestas com florestas em altitudes mais baixas é relativamente menor. Os modelos de distribuição potencial para espécies florestais montanas destacaram intensas modificações na área de ocupação dessas espécies em cenários climáticos para o Quaternário Tardio e sugerem que estas espécies possam ter ocorrido em altitudes e latitudes menores e longitudes maiores do que atualmente observado. Esses resultados sugerem que florestas com composição florística similar às atuais florestas alto-montanas possam ter ocupado uma área mais extensa no passado, formando em algumas regiões florestas mais extensas que foram posteriormente fragmentadas e confinadas ao topo de cadeias montanhosas na região leste ao sul do Brasil. / Abstract: The "Serra Fina" is the name given to a block of the Serra da Mantiqueira, a mountain chain that forms the boundary between the states of Minas Gerais, São Paulo, and Rio de Janeiro, southeastern Brazil. The Serra Fina largely corresponds to a massif of alkaline rocks and forms the highest part of the range, rising to more than 2500m at several points. It offers an exceptionally extensive altitudinal gradient, with the occurrence of several high-montane vegetation formations. These formations are still relatively well-conserved, but are very poorly known. The main objectives of the present study were to analyze the floristic composition of some of the high-montane vegetation types, describe and analyze the phytosociological structure of the cloud forests, determine the degree of similarity between these forests and other montane forests in Brazil and to investigate possible explanations of the patterns seen, especially with regard to climate changes in the quaternary. A total of 393 species, of which seven are probably new to science, were collected in the grasslands, "candeia" scrub and cloud forests. The greatest species-level richness was found in the families Asteraceae, Poaceae, Melastomataceae, Rubiaceae, Cyperaceae, Fabaceae, Myrtaceae, Orchidaceae and Ericaceae. Two new species of Asteraceae, confined to grasslands above 2500m have been described and illustrated, and the remainder await more detailed studies by specialists. The species richness encountered demonstrates the importance of the contribution of high altitude areas to the overall diversity of the Atlantic Forest of eastern Brazil, and the phytogeographic importance of the Serra Fina with a large number of endemic species or species with restricted distributions with strong links to the Andean flora of western South America. The forests showed a number of characteristics typical of cloud forests, such as low richness, high density and a reduced canopy, with Myrsinaceae, Myrtaceae, Symplocaceae and Cunoniaceae as the most important families. The Serra da Mantiqueira upper montane forests showed their greatest floristic similarity to be with the cloud forests of southern Brazil and to some extent with the upper montane forests of the interior of Minas Gerais and the crest of the coastal range ("Serra do Mar") in São Paulo, though with a somewhat differentiated floristic composition. Similarities with the surrounding forest matrix at lower altitudes were much less. Models of potential distribution for montane forest species using scenarios for Late Quaternary conditions suggest that extensive modifications of currently observed distributions are likely to have occurred, with many species occupying much lower altitudes and latitudes, together with much greater longitudes. These results suggest that forests similar in composition to current upper montane forests may have occupied much more extensive areas in the past, forming an almost continuous forest that has subsequently been fragmented and confined to high mountain areas in the east-south Brazil. / Doutorado / Doutor em Biologia Vegetal

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-09-05T15:53:23Z No. of bitstreams: 1 juliagaiofurtadodemendonca.pdf: 4297836 bytes, checksum: 611aa9bbd15f00fc16fe7b8ca2925468 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-09-06T11:32:11Z (GMT) No. of bitstreams: 1 juliagaiofurtadodemendonca.pdf: 4297836 bytes, checksum: 611aa9bbd15f00fc16fe7b8ca2925468 (MD5) / Made available in DSpace on 2017-09-06T11:32:11Z (GMT). No. of bitstreams: 1 juliagaiofurtadodemendonca.pdf: 4297836 bytes, checksum: 611aa9bbd15f00fc16fe7b8ca2925468 (MD5) Previous issue date: 2017-06-19 / O Parque Estadual da Serra do Papagaio (PESP), situado na porção Meridional da Serra da Mantiqueira, sul de Minas Gerais, representa uma grande extensão de formações vegetacionais altimontanas com altitudes que alcançam 2.350 m. O objetivo deste trabalho foi conhecer a composição florística dos campos de altitude do PESP, suas relações fitogeográficas com outras áreas campestres das regiões Sul e Sudeste do Brasil e analisar a estrutura da vegetação ao longo de um gradiente altitudinal. Expedições mensais de campo foram realizadas entre maio de 2015 e outubro de 2016 para coleta de material botânico e realização dos inventários fitossociológicos. Para avaliar a estrutura da vegetação foi utilizado o método de interceptação em linha, com alocação de nove áreas abrangendo três faixas altitudinais entre 1.650 m e 2.050 m. Para analisar as relações fitogeográficas foram selecionadas 14 localidades do Sul e Sudeste do país. Foram realizadas análises de similaridade quantitativas e qualitativas além do cálculo da diversidade para cada faixa altitudinal para avaliar a formação de grupos relacionados à altitude. O primeiro capítulo traz a composição florística dos campos de altitude do PESP, onde foram encontradas 276 espécies, 159 gêneros e 48 famílias de angiospermas, sendo Asteraceae a família mais rica (58 spp.) e Baccharis o gênero mais representativo (12 spp.). Foram encontradas onze espécies sob algum grau de ameaça e duas espécies endêmicas do PESP. As análises fitogeográficas mostraram uma grande dissimilaridade florística entre as 14 localidades analisadas, indicando que as formações campestres são singulares e demandam atenção especial para a conservação. O segundo capítulo apresenta a distribuição das espécies ao longo de um gradiente altitudinal. Foram encontradas 96 espécies nas linhas amostradas, sendo Poaceae (64,3%), Melastomataceae (11,3%) e Asteraceae (8,7%) as famílias com maiores valores de cobertura. A diversidade de Shannon (H’) para cada altitude apontou um padrão similar na distribuição espacial das espécies, enquanto as análises de similaridade demonstraram um forte agrupamento das áreas localizadas em faixas altitudinais comuns, elucidando a importância da conservação dos campos de altitude para a manutenção da biodiversidade da flora altomontana. / The Parque Estadual da Serra do Papagaio (PESP) is located in the southern portion of Serra da Mantiqueira, south of Minas Gerais and represents a large expanse of altitudinal vegetation formations with altitudes that reach 2.350 m. The aim of this work was to carry out the floristic survey of the PESP altitude fields (campos de altitude), their phytogeographic relationships with other rural areas of Southern and Southeastern regions of Brazil, and to analyze the vegetation structure along an altitudinal gradient. Monthly expeditions were carried out between May 2015 and October 2016 for the collection of botanical material and the realization of phytosociological inventories. The line intercept method was used to evaluate the vegetation structure. Were inventoried nine areas covering three altitudinal ranges between 1.650 m and 2.050 m. In order to analyze the phytogeographic relations, were selected 14 localities of Brazil South and Southeast. Quantitative and qualitative similarities analyzes were carried out. In addition, the diversity index (H') were calculated for each altitudinal range in order to evaluate the formation of groups related to altitude. The first chapter presents the floristic composition of the PESP altitude fields, where 276 species, 159 genera and 48 families of angiosperms were found, with Asteraceae being the richest family (58 spp.) and Baccharis the most representative genus (12 spp.). Eleven species are in some threatness category and two species were considered endemic to the PESP. The phytogeographic analyzes showed a great floristic dissimilarity between the 14 localities analyzed, indicating that the formations are unique and require special attention for conservation. The second chapter presents the distribution of the species along an altitudinal gradient. 96 species were found in the sampled lines, with Poaceae (64.3%), Melastomataceae (11.3%) and Asteraceae (8.7%) being the families with the highest coverage values. The diversity of Shannon (H') for each altitude showed a similar pattern in the spatial distribution of species, while the similarity analyzes demonstrated a strong grouping of the areas located in common altitudinal bands, elucidating the importance of the conservation of altitude fields for the maintenance of the biodiversity of the high altitude flora.