Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / We performed this study in a fragment of Caatinga under anthropic influence in the county of Poço Verde, Sergipe state, Brazil, with the following objectives: (i) to assess the temporal dynamics of the structure, floristic composition, and ecological groups of woody vegetation after four years with the hypothesis of reducing of the floristic and structural complexity with return of succession stage; (ii) to quantify the stocks aboveground of biomass and carbon, to assess the temporal dynamics of these stocks after four years, and to analyze the relationship of biomass with abundance and richness, all these in the woody vegetation, with the hypothesis of temporal reduction of stocks and positive correlations between biomassabundance and biomass-richness; and (iii) to analyze the structure, floristic composition, and stocks of biomass and carbon of herbaceous vegetation, seeking to relate the results to the anthropic pressure of fragment. Compared with a previous study (2011 - t0), the current data (2015 - t1) were obtained from 30 plots of 20 x 20 m, measuring individuals with circumference at breast height ≥ 6 cm. The species were classified according to ecological group through a subjective criterion, the biomass was estimated using allometric equations and the carbon stock with the following relationship: carbonstock = biomass*0.47. Significant temporal differences were tested (α<0.05) for richness, density, basal area and biomass stock (paired t test), for value of importance and ecological groups (x² of McNemar), and for Shannon-Wiener diversity - H' (t test of Hutcheson). The relationship of biomass with the abundance and richness were assessed by regression analysis. For herbaceous vegetation were used 30 subplots of 1 x 1 m within the plots of 20 x 20 m. The floristic composition was complemented around these subplots and biomass estimated by collecting and weighing the plants present in the subplots and then multiplied by 0.47 to estimate the carbon stock. We showed an increase of density (0.79%) and basal area (4.82%). The biomass stock was estimated at 52.79 t.ha-1 at t0 and 54.93 t.ha-1 at t1 (0.53 t.ha.year-1) and the carbon at 24.81 t.ha-1 at t0 and 25.82 t.ha-1 at t1 (0.25 t.ha.year-1). Changes in the floristic composition and structure were minimal and the H’ decreased from 3.33 to 3.30 nats.ind-1 keeping the plant community at the same succession stage. None of parameters evaluated differed significantly between the two surveys (p>0.05), indicating that the community is stable over time. The abundance and richness were not correlated with the biomass (p>0.05). For herbaceous vegetation we found 80 species and 34 families. The families of most species richness were Asteraceae, Malvaceae and Poaceae (seven species each). In the area of subplots were found a density of 32.46 ind/m², basal area of 41.6 m².ha-1 and a carbon stock of 108.45 kg.ha-1 in the biomass of 230.76 kg.ha-1. We found H' of 2.42 nats.ind-1 and the Pielou evenness of 0.67. The results show that the studied plant community has not suffered reducing of floristic and structural complexity, with a maintain in the time of their stock of biomass, locally contributing to carbon storage. Moreover, without the influence of parameters abundance and richness, biomass stocks may remain unchanged in the event of reductions in these parameters. The human disturbance recorded caused moderate influence on herbaceous vegetation, but we suggest that the intensity of these have not been sufficient to set up degradation. The studied plant community tolerate current levels of human disturbance, enabling the use of its resources through a planned management, an alternative for conservation. / O presente estudo foi conduzido em um fragmento de Caatinga antropizado no município de Poço Verde, Sergipe, com os seguintes objetivos: (i) avaliar a dinâmica temporal da estrutura, da composição florística e dos grupos ecológicos da vegetação lenhosa após quatro anos com a hipótese de redução da complexidade florística e estrutural com retrocesso do estágio sucessional; (ii) quantificar os estoques aéreos de biomassa e de carbono, avaliar a dinâmica temporal destes estoques após quatro anos e analisar a relação da biomassa com a abundância e riqueza, todos estes na vegetação lenhosa, com as hipóteses de redução temporal dos estoques e de correlações positivas entre biomassa-abundância e biomassa-riqueza; e (iii) analisar a estrutura, a composição florística e os estoques de biomassa e carbono do componente herbáceo, buscando-se relacionar os resultados com a antropização do fragmento. Comparados com um estudo anterior (2011 - t0), os dados atuais (2015 - t1) foram obtidos através 30 parcelas de 20 x 20 m, medindo indivíduos com circunferência à altura do peito ≥ 6 cm. As espécies foram classificadas quanto ao grupo ecológico através de um critério subjetivo, a biomassa foi estimada através de equações alométricas e o estoque de carbono com a seguinte relação: est.carbono = biomassa*0,47. Diferenças temporais significativas (α<0,05) foram testadas para a riqueza, densidade, área basal e estoque de biomassa (teste t pareado), para valor de importância e grupos ecológicos (x² de McNemar) e para diversidade Shannon-Wiener - H' (teste t de Hutcheson). As relações da biomassa com a abundância e a riqueza foram avaliadas por análises de regressão. Para as herbáceas foram utilizadas 30 subparcelas de 1 x 1 m dentro das parcelas de 20 x 20 m. Coletas adicionais de espécies vegetais férteis foram realizadas no entorno das subparcelas e a biomassa foi estimada através de coleta e pesagem das plantas nas subparcelas e a seguir multiplicada por 0,47 para estimar o estoque de carbono. Para a avaliação temporal da vegetação lenhosa, constatou-se um aumento de densidade (0,74%) e área basal (4,82%). O estoque de biomassa foi estimado em 52,79 Mg.ha-1 em t0 e 54,93 Mg.ha-1 em t1 (0,53 Mg.ha.ano-1) e o de carbono em 24,81 Mg.ha- 1 em t0 e 25,82 Mg.ha-1 em t1 (0,25 Mg.ha.ano-1). Alterações na composição florística e estrutura foram mínimas e o índice de H’ diminuiu de 3,33 para 3,30 nats.ind-1 e a comunidade manteve-se em mesmo estágio sucessional. Nenhum dos parâmetros avaliados diferiu significativamente entre os dois levantamentos (p>0,05), apontando que a comunidade se encontra estável no tempo. A biomassa não foi correlacionada com a abundância e a riqueza (p>0,05). Para a vegetação herbácea foram encontradas 80 espécies e 34 famílias. As famílias de maior riqueza foram Asteraceae, Malvaceae e Poaceae (sete espécies cada). Na área das subparcelas foi encontrada uma densidade de 32,46 ind/m², uma área basal de 41,6 m².ha-1 e um estoque de carbono de 108,45 kg.ha-1 numa biomassa de 230,76 kg.ha-1. Foi encontrado um índice de H’ de 2,42 nats.ind-1 e uma equabilidade de Pielou de 0,67. Os resultados apontam que a comunidade vegetal estudada não sofreu redução temporal de sua complexidade florística e estrutural, com uma manutenção temporal de seu estoque de biomassa, contribuindo localmente para o armazenamento de carbono. Além disso, sem influência da abundância e da riqueza, os estoques de biomassa podem manter-se inalterados diante de reduções nestes parâmetros. Considerando-se ainda que os impactos antrópicos registrados causaram moderada influência na vegetação herbácea, acredita-se que a intensidade destes não tenham sido suficientes para configurar uma degradação. A comunidade vegetal estudada tolera os atuais níveis de antropização, viabilizando o uso de seus recursos através de um manejo planejado, uma alternativa para a conservação.

[pt] Do ponto de vista histórico, a cafeicultura teve um papel relevante sobre a composição e estrutura das florestas no domínio da Mata Atlântica, especialmente no século XIX em todo o Vale do Rio Paraíba do Sul, localizado na interceção dos estados de SP, RJ e MG. Esta atividade gerou uma paisagem composta por mosaicos florestais que foram definidos por diferentes sobreposições de usos, em distintas escalas temporais. Seu legado deixou marcas na paisagem e muitas estão ocultas sob estes mosaicos vegetacionais, sendo revelados a partir do estudo de sua flora e vegetação. Este trabalho teve como objetivo avaliar a composição florística e a estrutura do estrato arbustivo e arbóreo de fragmentos de Mata Atlântica no Vale do Paraíba RJ/SP, com diferentes estágios sucessionais e distintas sobreposições de usos após o ciclo do café. Foi analisada a estrutura floristica e fitossociológica de oito fragmentos que compartilham o mesmo histórico de uso. Em seguida, foram analisadas as marcas humanas nestas florestas através do inventário de espécies exóticas e vestígios físicos de diferentes contextos históricos. Por fim, foi feita uma análise do entorno de cada fragmento por imagens de satélite. A metologia utilizada consistiu: 1) no levantamento fitossociológico em 20 parcelas de 10 x 10 m2 contíguas, perfazendo 0,2 ha em cada fragmento; 2) análise granulométrica e de fertilidade do solo nas profundidades de 0-10 e 10-20 cm; 3) levantamento de espécies exóticas nas florestas; 4) registros de macrovestígios de usos pretéritos nos fragmentos e 5) utilização e interpretação de imagens de satélite para cada fragmento estudado. Os resultados indicam que os fragmentos estudados contemporâneos à época do café. Muito possivelmente são de áreas onde onde anteriomente existiam cafezais e, com o declinio deste, deu-se o processo de sucessão ecológica, representando hoje esta paisagem uma convergência de histórias naturais e humanas. As investigações acerca da paisagem que circunda os fragmentos dimensiona as semelhanças que há entre eles, pois estão dentro de uma mesma matriz e contexto histórico. A interpretação destes eventos temporais sobre os aspectos das florestas a partir do legado do café por diferentes sobreposições de uso contribui para compreensão das dimensões biogeográficas e da história ambiental da sua paisagem. Neste contexto, o entendimento dos usos antrópicos pretéritos e a situação atual das florestas face ao aspecto cumulativo de usos contribui para a conservação destas florestas e dos valores ecológicos e culturais a elas associados. / [en] From a historical point of view, the heyday of coffee growing played a relevant role in the composition and structure of forests in the Atlantic Forest domain, especially in the 19th century throughout the Paraíba do Sul River Valley, located at the intersection of the states of SP, RJ, and MG. This activity generated a landscape composed of forest mosaics defined by overlapping uses at different time scales. His legacy left marks on the landscape, and many are hidden under these vegetation mosaics, revealed through the study of its flora and vegetation. This work aimed to evaluate the floristic composition and structure of the shrub and arboreal layer of Atlantic Forest fragments in the Paraíba Valley RJ/SP, with different successional stages and distinctions overlapping uses after the coffee cycle. The floristic and phytosociological structure of eight fragments that share the same history of use was analyzed. Then, the human marks in these forests were analyzed by inventory of exotic species and physical remains from different historical contexts. Finally, an analysis of the surroundings of each fragment was carried out using satellite images. The methodology used consisted of 1) a phytosociological survey with 20 contiguous plots of 10 x 10 m2, totaling 0.2 ha in each fragment; 2) granulometric and soil fertility analysis at depths of 0-10 and 10-20 cm; 3) survey of exotic species in forests; 4) records of a macro trace of past uses in the fragments and 5) use and interpretation of satellite images for each studied component. The results indicate that the studied fragments are not contemporary remnants of the coffee period. Quite possibly, they were from areas where coffee plantations previously existed and, with its decline, the process of ecological succession took place. Today, this landscape represents a convergence of natural and human histories. The investigations about the landscape surrounding the fragments scale the similarities between them, as they are within the same matrix and historical context. The interpretation of these temporal events on the aspects of forests from the coffee legacy through different use overlaps contributes to understanding the biogeographic dimensions and the environmental history of its landscape. In this context, understanding past anthropic uses and the current situation of forests in the face of the cumulative aspect of benefits contributes to the conservation of these forests and the ecological and cultural values associated with them.

The movements of two vervet monkey troops were studied to determine whether they optimize their rate of food intake in relation to seasonal energy availability. The effect of variation in habitat structure on the troops’ foraging strategies while utilizing temporally and spatially distributed resources was determined. Troop home range boundaries were delineated, the various plant communities and species utilised by the troops identified and classified, and variations in home range and vegetation structure were reported. The diets of the troops were determined and compared. Effects of coexistence on competition were assessed. Vervet food trees were randomly selected, marked and seasonal phenological data collected. Samples of food items constituting the two troops diets were collected for energy analysis. Using geostatistical interpolation techniques, monthly energy values were extrapolated onto home range grids for the two vervet monkey troops. Grids were stored as database files that were interrogated through GIS simulation models. Using the stochastic processes inherent in Markov chain theory, a series of non-returning random walks were simulated for comparison to original routes taken by the two troops. Results from comparisons of home range energy, day range lengths and areas, shortest route energy to actual route energy, time spent in high energy areas, and energy utilisation from actual and randomly generated routes indicated that the two troops optimize resource energy available to them by adopting flexible foraging strategies. In environments where temporal and spatial variations in habitat structure affect the distribution of resources, it is essential that animals develop optimal foraging strategies to survive. For the two troops investigated, foraging strategies fluctuate between being time minimizers in more heterogeneous environments where resources are abundant, and energy maximisers in homogeneous environments where resources are constrained by low diversity and seasonality. / Environmental Sciences (Department) / D.Litt et Phil (Environmental Management)

À partir des années 1970 et notamment à travers les travaux de Tüxen (1978) puis de Géhu & Rivas-Martínez (1981), la phytosociologie dynamico-caténale a permis de mieux intégrer la dynamique des végétations en décrivant plus finement les trajectoires dynamiques des séries de végétation. Si les méthodologies d’étude des dynamiques des végétations se sont multipliées depuis les dernières décennies en Europe, de tels travaux restent peu nombreux en France. Un programme national de Cartographie des Habitats naturels et semi-naturels (CarHAB), lancé par le Ministère de l’Écologie, du Développement Durable et de l’Énergie, à partir de 2011, a pour objectif de cartographier les végétations et les séries de végétation de France métropolitaine à l’échelle du 1 : 25 000 d’ici 2025. Dans ce contexte, la Corse a été choisie comme région "pilote" pour les particularités de ses végétations méditerranéenne et alticole. Au-delà de cette singularité, l’évolution de la société agropastorale au cours du XXe siècle a profondément marqué le paysage végétal de Corse et constitue une des problématiques fondamentales permettant d’appréhender les changements des trajectoires dynamiques des végétations. La démarche méthodologique repose sur une méthode inductive et semi-déductive qui permet de décrire les systèmes de végétation de la Corse, à partir d’une approche phytosociologique. Notre étude, d’abord consacrée à l’approche bioclimatique, géomorphologique et phytogéographique, permet de typifier et de spatialiser les unités écologiques (géologie, géomorphologie, pédologie et bioclimatologie) afin de mieux appréhender les patrons écologiques qui régissent l’agencement et les zonations des végétations et plus largement les séries et les géoséries de végétation. Les fondements de la phytosociologie paysagère ont été révisés et adaptés aux objectifs de gestion conservatoire et d’aménagement du territoire, dans le cadre du programme CarHAB. 78 unités, soit 34 séries, 14 minoriséries et 30 géopermaséries sont décrites selon plusieurs critères : écologie, chorologie, structure et nomenclature de la tête de série, trajectoires dynamiques et conservation. Une méthode cartographique a été élaborée pour spatialiser les unités sigmétales et géosigmétales. L’ensemble des travaux cartographiques est présenté sous la forme d’un atlas cartographique concernant huit vallées et plateaux (Asco, Cap Corse, Niolu, Castagniccia, Haut-Vénacais, Plateau du Cuscione, Plateau calcaire de Bonifacio) et 31 sites littoraux.Quelques méthodes de bioévaluation sont testées et discutées, pour répondre aux enjeux de conservation des séries et des géoséries de végétation ainsi que de territoires protégés (étang de Biguglia, massif du Haut-Vénacais). / Since the 1970’s and particularly through the works of Tüxen (1978) and Géhu & Rivas-Martínez (1981), the dynamico-catenal phytosociology allowed to better integrate vegetation dynamics, by describing more precisely the dynamic trajectories of vegetation series. If vegetations dynamic study methodologies have been developped over the recent decades in Europe, such works still remain scarce in France. A national program of habitat mapping (CarHAB), launched by the Ministry of Ecology, since 2011, aims to map the vegetation and vegetation series of metropolitan France at the scale of 1: 25 000 up to 2025. Within this context, Corsica has been chosen as a "pilot" region, due to its peculiarities regarding mediterranean and alticole vegetations. Beyond this singularity, the evolution of agropastoral society over the twentieth century caused main changes the landscape of Corsica and represents a major issue to understand the changes of dynamic trajectories of vegetation. Our methodology, based on an inductive and semi-deductive phytosociological approach, allows to describe vegetationsystems of Corsica.This study, firstly focused on bioclimatology, geomorphology and phytogeography, allows to typify and spatialize ecological units, in order to better understand ecological patterns that govern the layout and the zonation of vegetation and more widely vegetation series and geoseries. The principles of landscape phytosociology have been revised and adapted to the conservation management aims and spatial planning of the CarHAB program. 78 units, 34 series, 14 minoriseries and 30 geopermaseries are presented according to several descriptive criteria: ecology, chorology, serie head structure and nomenclature, dynamics trajectories and conservation.A mapping method was developed to spatialize sigmetal and geosigmetal units : the outcomes are presented in a mapping atlas concerning eight valleys and trays (Asco, Cap Corse, Niolu, Fium-Alto, Haut-Vénacais, Cuscione, Bonifacio) and 31 coastal sites.A few bioevaluation methods are tested and discussed to match the challenges of conservation series and vegetation géoséries, as well as evaluation protected sites (Biguglia, Haut-Vénacais).

Em uma parcela permanente de 10,24 ha na Floresta Pluvial Atlântica Submontana do Parque Estadual Carlos Botelho (Sete Barras, SP, Brasil), este estudo teve o intuito de descrever o regime de distúrbio do dossel e avaliar a regeneração natural sob diferentes regimes de luz. Para tanto, foi realizado o levantamento de todas as clareiras da parcela, que foram mensuradas e tiveram sua idade aproximada estimada. Em seguida, foram instaladas 42 parcelas de 10x10m para avaliar a regeneração natural em três regimes luminosos: dossel contínuo (18 parcelas), clareiras pequenas a médias (11) e clareiras grandes com abundância de Guadua tagoara (Nees) Kunth (13). O regime de luz foi caracterizado por fotografias hemisféricas tomadas ao centro das parcelas. O estudo da regeneração natural foi divido em: estrato herbáceo (i.e., ervas menores que um metro de altura), avaliado através da cobertura do solo estimada pelo método de interceptação de linha; e estrato arbustivo, avaliado através dos indivíduos com altura maior que 1m, e com diâmetro à altura do peito menor que 5cm. Para estes indivíduos anotou-se a espécie, diâmetro, altura total e área de copa, além da presença de partes reprodutivas e substrato de germinação. Informações sobre hábito, grupo sucessional e síndrome de dispersão das espécies também foram obtidas. Após um ano, uma reavaliação permitiu analisar a mortalidade, danos, recrutamento e crescimento. Apesar de 67% das clareiras terem sido menores que 150 m2 , o regime de distúrbio foi atípico, principalmente pela contribuição de clareiras maiores que 750 m2 , e pela área média e total que variaram respectivamente de 419 a 799 m2 , e de 26 a 49%, dependendo do método de delimitação de clareira. A densidade foi de 6 clareiras.ha -1 e a taxa de recorrência variou entre 91 e 220 anos, dependendo dos métodos. Houve diferença significativa entre os ambientes para a maioria dos índices de luz, especialmente para a radiação total incidente com médias entre 909 e 2.400 mols.m-2.ano-1. Observou-se diferença significativa entre ambientes na cobertura por ervas, porém os resultados variaram entre espécies. No estrato arbustivo, houve diferença significativa na composição e abundância das espécies, inclusive entre clareiras médias e sub-bosque. A densidade de ervas e arbustos foi maior nos ambientes mais iluminados, assim como a densidade de pioneiras e secundárias iniciais. O recrutamento em um ano (16%) apresentou diferenças nos ambientes, com 63% dos recrutas apenas nas grandes clareiras. O mesmo não ocorreu com a taxa de mortalidade cujas principais causas foram os danos físicos e dessecamento. Para os 13% de indivíduos danificados em um ano, houve destaque para danos ligados à extração de palmito. Apenas os danos físicos naturais apresentaram diferença entre ambientes, com grandes clareiras sendo as mais danosas. No geral e entre as 25 espécies avaliadas separadamente, houve uma tendência de crescimento maior com o aumento da incidência luminosa. Clareiras pequenas a médias tiveram significativamente maior riqueza, diversidade e menor dominância de espécies que o sub-bosque. Clareiras grandes com bambu tiveram menor riqueza e diversidade, mas contribuíram com a manutenção da diversidade beta da parcela permanente. / In a 10.24 ha permanent plot of Tropical Lower Montane Atlantic Rain Forest in the Carlos Botelho State Park (Sete Barras, SP, Brazil), this study aimed to describe the canopy disturbance regime and to assess natural regeneration under different light regimes. In order to do so, the plot was completely surveyed for canopy gaps that were measured and had their approximate age estimated. Then, 42 10x10 m plots were established to evaluate natural regeneration under three light regimes: understory (18 plots), small to medium canopy gaps (11 plots) and large gaps abundant in Guadua tagoara (Nees) Kunth (13 plots). The light regime was characterized through hemispherical photographs taken at each plot center. Natural regeneration was dived into: herb stratum (i.e., herbs below one meter in height) assessed through soil coverage using the line intercept method; and shrub stratum or all plant individuals taller than one meter high and thinner than 5 cm in diameter at breast height. All individuals were identified to species and measured for diameter, height, crown height and area, besides notes on the presence of reproductive structures and germination substrate. Information on growth form, dispersal syndrome and ecological group were also obtained for each species. After one year, one reevaluation was made to assess mortality, damages, recruitment and growth. Although 67% of gaps were smaller than 150 m2 , the plot disturbance regime was atypical mainly by the contribution of gaps bigger than 750 m2 and by the average and total gap area that varied respectively from 419 to 799 m2 , and from 26 to 49% depending on the gap delimitation method. Gap density was 6 gaps.ha-1 and the turnover rate varied from 91 to 220 years depending on the gap method employed. There was significant difference between environments among the light index, especially for total incident radiation with means varying from 909 and 2,400 mols.m-2.y-1. It was found significant differences on herb soil coverage between environments, although the results varied among species. In the shrub stratum, species composition and abundance was significantly different, even between small to medium canopy gaps and the understorey. Herb and shrub densities were bigger in the more enlightened environments, as well as pioneer and early secondary species densities. Recruitment over the year (16%) was different between environments with large gaps accounting for 63% of all recruits. Similar difference was not found for mortality rate that had physical damage and desiccation as main death causes. Amid the 13% of damage individuals in the course of one year, there was noticeable contribution of damages linked to illegal extraction of palm-heart. Differences between environments were present only for physical damages with large gaps being the most damaging environment. In general and among the 25 species evaluated separately, there was a tendency of bigger growth with enhancement in light incidence. Small to medium gaps had significantly higher species richness and diversity, and lower dominance compared to the understorey. Large gaps had lower richness and diversity, but they contributed to maintain beta diversity of the permanent plot.

Στην παρούσα διδακτορική διατριβή εκθέτονται η χλωρίδα των Βαρδουσίων ορέων καθώς και τα δεδομένα που προκύπτουν από την διερεύνηση – ανάλυσή της. Στο πεδίο της βλάστησης (φυτοκοινωνιολογία), έχει επιβεβαιωθεί σχεδόν το σύνολο των προηγούμενων αναφορών και έχει συμπληρωθεί με νέα δεδομένα όσο αφορά τις φυτοκοινωνιολογικές ομαδοποιήσεις. Συγχρόνως δικαιολογήθηκε και εξηγήθηκε η ύπαρξη των φυτοκοινωνιολογικών μονάδων σε σχέση με το σύνολο των οικολογικών παραγόντων που ήταν δυνατό να ληφθούν υπόψη (μικροκλίμα, εδαφικοί παράγοντες, γεωλογικό - πετρολογικό υπόστρωμα), συμβάλλοντας έτσι στην συνοικολογική προσέγγιση του θέματος. Επίσης όπου ήταν δυνατό έγινε προσπάθεια να διερευνηθεί η δυναμική εξέλιξης των περισσότερων φυτοκοινωνιολογικών ομάδων, όπως αυτή διαμορφώνεται κάτω από την επίδραση των περιβαλλοντικών μεταβλητών. Πιο κάτω ακολουθεί μια συνοπτική περιγραφή των σημαντικότερων σημείων της διδακτορικής διατριβής, καθώς και τα συμπεράσματα που μπορούν να διατυπωθούν από τα αποτελέσματα της ερευνητικής αυτής προσπάθειας. / In the present doctoral thesis the flora of Mt. Vardousia, as well as the data that have resulted from its analysis are presented. From a vegetation (plant sociology) point of view, almost all the previous reports on the mountain have been confirmed and have been enriched with new data as far as phytosociological groups are concerned. Additionally, the existence of certain phytosociological units was justified and explained based on the ecological factors that were possible to be measured (microclimate, soil, geology, geological substrate), contributing in this way to the synecological approach of the subject. Also, where feasible, an effort was done to study the dynamics of succession of most of the phytosociological groups, as they depend on various environmental variables. A concise description of the most important points of the doctoral thesis, as well as the conclusions that can be extracted from the results of this research follow.

Em uma parcela permanente de 10,24 ha na Floresta Pluvial Atlântica Submontana do Parque Estadual Carlos Botelho (Sete Barras, SP, Brasil), este estudo teve o intuito de descrever o regime de distúrbio do dossel e avaliar a regeneração natural sob diferentes regimes de luz. Para tanto, foi realizado o levantamento de todas as clareiras da parcela, que foram mensuradas e tiveram sua idade aproximada estimada. Em seguida, foram instaladas 42 parcelas de 10x10m para avaliar a regeneração natural em três regimes luminosos: dossel contínuo (18 parcelas), clareiras pequenas a médias (11) e clareiras grandes com abundância de Guadua tagoara (Nees) Kunth (13). O regime de luz foi caracterizado por fotografias hemisféricas tomadas ao centro das parcelas. O estudo da regeneração natural foi divido em: estrato herbáceo (i.e., ervas menores que um metro de altura), avaliado através da cobertura do solo estimada pelo método de interceptação de linha; e estrato arbustivo, avaliado através dos indivíduos com altura maior que 1m, e com diâmetro à altura do peito menor que 5cm. Para estes indivíduos anotou-se a espécie, diâmetro, altura total e área de copa, além da presença de partes reprodutivas e substrato de germinação. Informações sobre hábito, grupo sucessional e síndrome de dispersão das espécies também foram obtidas. Após um ano, uma reavaliação permitiu analisar a mortalidade, danos, recrutamento e crescimento. Apesar de 67% das clareiras terem sido menores que 150 m2 , o regime de distúrbio foi atípico, principalmente pela contribuição de clareiras maiores que 750 m2 , e pela área média e total que variaram respectivamente de 419 a 799 m2 , e de 26 a 49%, dependendo do método de delimitação de clareira. A densidade foi de 6 clareiras.ha -1 e a taxa de recorrência variou entre 91 e 220 anos, dependendo dos métodos. Houve diferença significativa entre os ambientes para a maioria dos índices de luz, especialmente para a radiação total incidente com médias entre 909 e 2.400 mols.m-2.ano-1. Observou-se diferença significativa entre ambientes na cobertura por ervas, porém os resultados variaram entre espécies. No estrato arbustivo, houve diferença significativa na composição e abundância das espécies, inclusive entre clareiras médias e sub-bosque. A densidade de ervas e arbustos foi maior nos ambientes mais iluminados, assim como a densidade de pioneiras e secundárias iniciais. O recrutamento em um ano (16%) apresentou diferenças nos ambientes, com 63% dos recrutas apenas nas grandes clareiras. O mesmo não ocorreu com a taxa de mortalidade cujas principais causas foram os danos físicos e dessecamento. Para os 13% de indivíduos danificados em um ano, houve destaque para danos ligados à extração de palmito. Apenas os danos físicos naturais apresentaram diferença entre ambientes, com grandes clareiras sendo as mais danosas. No geral e entre as 25 espécies avaliadas separadamente, houve uma tendência de crescimento maior com o aumento da incidência luminosa. Clareiras pequenas a médias tiveram significativamente maior riqueza, diversidade e menor dominância de espécies que o sub-bosque. Clareiras grandes com bambu tiveram menor riqueza e diversidade, mas contribuíram com a manutenção da diversidade beta da parcela permanente. / In a 10.24 ha permanent plot of Tropical Lower Montane Atlantic Rain Forest in the Carlos Botelho State Park (Sete Barras, SP, Brazil), this study aimed to describe the canopy disturbance regime and to assess natural regeneration under different light regimes. In order to do so, the plot was completely surveyed for canopy gaps that were measured and had their approximate age estimated. Then, 42 10x10 m plots were established to evaluate natural regeneration under three light regimes: understory (18 plots), small to medium canopy gaps (11 plots) and large gaps abundant in Guadua tagoara (Nees) Kunth (13 plots). The light regime was characterized through hemispherical photographs taken at each plot center. Natural regeneration was dived into: herb stratum (i.e., herbs below one meter in height) assessed through soil coverage using the line intercept method; and shrub stratum or all plant individuals taller than one meter high and thinner than 5 cm in diameter at breast height. All individuals were identified to species and measured for diameter, height, crown height and area, besides notes on the presence of reproductive structures and germination substrate. Information on growth form, dispersal syndrome and ecological group were also obtained for each species. After one year, one reevaluation was made to assess mortality, damages, recruitment and growth. Although 67% of gaps were smaller than 150 m2 , the plot disturbance regime was atypical mainly by the contribution of gaps bigger than 750 m2 and by the average and total gap area that varied respectively from 419 to 799 m2 , and from 26 to 49% depending on the gap delimitation method. Gap density was 6 gaps.ha-1 and the turnover rate varied from 91 to 220 years depending on the gap method employed. There was significant difference between environments among the light index, especially for total incident radiation with means varying from 909 and 2,400 mols.m-2.y-1. It was found significant differences on herb soil coverage between environments, although the results varied among species. In the shrub stratum, species composition and abundance was significantly different, even between small to medium canopy gaps and the understorey. Herb and shrub densities were bigger in the more enlightened environments, as well as pioneer and early secondary species densities. Recruitment over the year (16%) was different between environments with large gaps accounting for 63% of all recruits. Similar difference was not found for mortality rate that had physical damage and desiccation as main death causes. Amid the 13% of damage individuals in the course of one year, there was noticeable contribution of damages linked to illegal extraction of palm-heart. Differences between environments were present only for physical damages with large gaps being the most damaging environment. In general and among the 25 species evaluated separately, there was a tendency of bigger growth with enhancement in light incidence. Small to medium gaps had significantly higher species richness and diversity, and lower dominance compared to the understorey. Large gaps had lower richness and diversity, but they contributed to maintain beta diversity of the permanent plot.

The movements of two vervet monkey troops were studied to determine whether they optimize their rate of food intake in relation to seasonal energy availability. The effect of variation in habitat structure on the troops’ foraging strategies while utilizing temporally and spatially distributed resources was determined. Troop home range boundaries were delineated, the various plant communities and species utilised by the troops identified and classified, and variations in home range and vegetation structure were reported. The diets of the troops were determined and compared. Effects of coexistence on competition were assessed. Vervet food trees were randomly selected, marked and seasonal phenological data collected. Samples of food items constituting the two troops diets were collected for energy analysis. Using geostatistical interpolation techniques, monthly energy values were extrapolated onto home range grids for the two vervet monkey troops. Grids were stored as database files that were interrogated through GIS simulation models. Using the stochastic processes inherent in Markov chain theory, a series of non-returning random walks were simulated for comparison to original routes taken by the two troops. Results from comparisons of home range energy, day range lengths and areas, shortest route energy to actual route energy, time spent in high energy areas, and energy utilisation from actual and randomly generated routes indicated that the two troops optimize resource energy available to them by adopting flexible foraging strategies. In environments where temporal and spatial variations in habitat structure affect the distribution of resources, it is essential that animals develop optimal foraging strategies to survive. For the two troops investigated, foraging strategies fluctuate between being time minimizers in more heterogeneous environments where resources are abundant, and energy maximisers in homogeneous environments where resources are constrained by low diversity and seasonality. / Environmental Sciences (Department) / D.Litt et Phil (Environmental Management)

These studies were undertaken in the state of Mato Grosso, Brazil, in the area of Chapada dos Guimarães and Baixada Cuiabana, which are constituted of a high plateau and a big low plain, respectively, being limited to two areas covered by vegetation with a savannic physiognomy, type Cerrado stricto sensu. Considering the hypothesis that the knowledge both of the biotic and abiotic components of the scenery and their interrelations allows a better understanding of the environmental dynamic, this dissertation had as objectives to characterize the savanna communities' arboreal stratum floristically and phytosociologically, concerning their richness, phytosociological structures and diversity; to identify floristic groupings through varied statistical techniques, representing them by dendrograms; to select species which are really able to make discrimination among the groups; to obtain some discriminant functions to allow classification and reclassification of specimen units, in the groups, to which they have more probability of belonging; to analyze and to characterize the obtained groups; to determine the patterns of distribution of the species of trees by the analysis of correlations of environmental variables with the distribution of the species and plots in the communities being studied; to determine the similarity indexes among the floristic groups and to compare themselves and, finally, to test methods of assorted statistical analysis for application in studies of vegetable communities. Data of vegetation were obtained by the method of multiple plots, with size of 20 X 20 m (400 m2), randomly disposed in each one of the areas being studied. 82 plots were randomly installed. In each one of the 82 patternless units, the circumferences of all the arboreal plants with perimeter to 0,30 m from the level of the soil (PAB) larger or equal to 15,7 cm (DAB 5,0 cm) and the total height of the plants were obtained. In the core of each plot, for determination of the chemical and textural variables of the soil, simple samples of superficial soil were collected (0-30 cm depth). Species were organized according to the families recognized by Angiosperm Phylogeny Group II. The sampling sufficiency was obtained based on the analysis of the curve of the collector. Phytosociological parameters were calculated for each formed group, with the purpose of characterizing them phytosociologically. Having as variables the Index of Covering Value (IVC) of the species, the classification was accomplished by the TWINSPAN (Two-Way Indicator Species Analysis) method, regarding the plots, with the objective of classifying them in floristic groups. The diversity was determined by the Shannon-Wienner and the Simpson Index. The discriminant analysis was undertaken through the STEPWISE method. Considering the matrix of presence and absence of the species in the groups, the floristic similarity was calculated among the groups by the Sorensen Index. To evaluate the hypothesis of the correlation existence between the distribution of the species and environmental variables, the canonical correspondence analysis was accomplished (CCA). The test of permutation of Monte Carlo was applied to verify the importance of the correlations between the emerging distribution patterns of the species and the environmental variables in final CCA. To determine the responsible environmental factors for the distribution of the species, the analysis of regression logistics was used. The Forward Stepwise (Wald) method was used for the sequential selection of the variables. By the species-area curve, it could be observed that, from the plot 75 (30.000 m2 out of the area used as sample), the curve is stabilized with the occurrence of 114 species in the 82 studied plots, distributed between 81 genera and 36 botanical families. The families better represented were Fabaceae, Myrtaceae and Vochysiaceae. The alpha diversity from the arboreal vegetation found in the area being studied was of 4,033 considering the Shannon-Wiener Index and of 0,975 considering the Simpson Index, representing a great floristic diversity. The divisions generated by the classification through the TWINSPAN method separated the plots into four groups: Group 1 Myrcia albo-tomentosa Camb. Association; Group 2 Pterodon emarginatus Vog. Association ; Group 3 Curatella americana L. Association; and Group 4 Qualea multiflora Mart. Association. In the discriminant analysis, 100% of the plots were classified correctly in the Groups 1, 2, 3 and 4, indicating precision of the grouping technique used. The largest similarity could be observed in the Groups 2 and 3, whose Sorensen Index was close to 1 (0,7310). In the four floristic groups, Fabaceae, Myrtaceae, Vochysiaceae, Annonaceae and Apocynaceae families were the most representative floristically in terms of genera and species. In CCA the correlations of the environmental variables with the first ordination axis were, in decreasing order of absolute values, saturation for aluminum, altitude s.n.m., saturation of bases, saturation for magnesium, relationship magnesium/potassium, saturation for hydrogen, potassium tenor, pH(H2O) and relationship calcium/potassium. The saturation for calcium variable presented very weak correlation with the first axis, however, with the second ordination axis, it was very strong. In the diagram of ordination of the plots, the four floristic groups were discriminated in sections different from the diagram, reinforcing their visualization as much defined habitats and with composition of particular species, resulting in clear separation of the four soil classes previously identified. The logistic regression analysis was useful to prove the results obtained from CCA, concerning the environmental variables which determined the distribution of the indicative species of the floristic groups in the studied communities. / Estes estudos foram desenvolvidos no estado de Mato Grosso, Brasil, na região de Chapada dos Guimarães e Baixada Cuiabana, que compreendem, respectivamente, um alto platô e uma grande planície baixa, restringindo-se a duas áreas cobertas por vegetação com fisionomia savânica do tipo Cerrado stricto sensu. Partindo-se da hipótese de que o conhecimento tanto dos componentes bióticos e abióticos da paisagem como de suas inter-relações permite um melhor entendimento da dinâmica ambiental, o presente estudo teve como objetivos caracterizar o estrato arbóreo das comunidades de savana estudadas, florística e fitossociologicamente, quanto a riqueza, estrutura fitossociológica e diversidade; identificar agrupamentos florísticos, por meio de técnicas estatísticas multivariadas, representando-os por meio de dendrograma; selecionar espécies com poder real de discriminação entre os grupos; obter funções discriminantes que permitam classificar e reclassificar unidades amostrais, nos grupos, para os quais têm maior probabilidade de pertencerem; analisar e caracterizar os grupos obtidos; determinar os padrões de distribuição das espécies de árvores, por meio da análise de correlações de variáveis ambientais com a distribuição das espécies e parcelas nas comunidades estudadas; determinar os índices de similaridade entre os grupos florísticos obtidos e compará-los; e testar métodos de análise estatística multivariada para aplicação em estudos de comunidades vegetais. Os dados da vegetação foram obtidos empregando-se o método de parcelas múltiplas, com tamanho de 20 X 20 m (400 m2), dispostas aleatoriamente em cada uma das áreas de estudos. Foram instaladas aleatoriamente 82 parcelas. Em cada uma das 82 unidades amostrais, foram obtidas as circunferências de todos as plantas arbóreas com perímetro a 0,30 m do nível do solo (PAB) maior ou igual a 15,7 cm (DAB  5,0 cm), e a altura total das plantas. No centro de cada parcela, para determinação das variáveis químicas e texturais do solo, coletaram-se amostras simples de solo superficial (0-30 cm de profundidade). As espécies foram organizadas de acordo com as famílias reconhecidas pelo Angiosperm Phylogeny Group II. A suficiência de amostragem foi obtida com base na análise da curva do coletor. Os parâmetros fitossociológicos foram calculados para cada grupo formado, com a finalidade de caracterizá-los fitossociológicamente. Tendo como variáveis o Índice de Valor de Cobertura (IVC) das espécies, foi realizada a classificação, por meio do método TWINSPAN (Two-Way Indicator Species Analisys), com relação às parcelas, com o objetivo de classificá-las em grupos florísticos. A diversidade foi determinada por meio do Índice de Shannon-Wienner e de Simpson. Realizou-se a análise discriminante por meio do método STEPWISE. A partir da matriz de presença e ausência das espécies nos grupos, foi calculada a similaridade florística entre os grupos, por meio do Índice de Sorensen. Para avaliar a hipótese da existência de correlação entre a distribuição das espécies e variáveis ambientais, foi realizada a análise de correspondência canônica (CCA). Foi aplicado o teste de permutação de Monte Carlo para verificar a significância das correlações entre os padrões de distribuição emergentes das espécies e as variáveis ambientais na CCA final. Para determinar os fatores ambientais responsáveis pela distribuição das espécies, foi utilizada a análise de regressão logística. À seleção seqüencial das variáveis foi utilizado o método Forward Stepwise (Wald). Pela curva espécie-área, pode-se observar que, a partir da parcela 75 (30.000 m2 da área amostrada), a curva estabiliza-se com a ocorrência de 114 espécies nas 82 parcelas estudadas, distribuídas entre 81 gêneros e 36 famílias botânicas. As famílias mais bem representadas foram Fabaceae, Myrtaceae e Vochysiaceae. A diversidade alfa da vegetação arbórea encontrada na área estudada foi de 4,033 pelo índice de Shannon-Wiener e de 0,975 pelo de Simpson, indicando alta diversidade florística. As divisões geradas pela classificação por meio do método TWINSPAN separaram as parcelas em quatro grupos. Grupo 1 - Associação Myrcia albo-tomentosa Camb.; Grupo 2 - Associação Pterodon emarginatus Vog.; Grupo 3 - Associação Curatella americana L.; e Grupo 4 - Associação Qualea multiflora Mart.. Na análise discriminante, observou-se que 100% das parcelas foram classificadas corretamente nos grupos 1, 2, 3 e 4, indicando precisão da técnica de agrupamento utilizada. A maior similaridade se deu entre os grupos 2 e 3, cujo índice de Sorensen foi próximo de 1 (0,7310). Nos quatro grupos florísticos obtidos, as famílias Fabaceae, Myrtaceae, Vochysiaceae, Annonaceae e Apocynaceae foram as mais representativas florísticamente em número de gêneros e espécies. Na CCA, as correlações das variáveis ambientais com o primeiro eixo de ordenação foram, em ordem decrescente de valores absolutos, saturação por alumínio, altitude s.n.m., saturação de bases, saturação por magnésio, relação magnésio/potássio, saturação por hidrogênio, teor de potássio, pH(H2O) e relação cálcio/potássio. A variável saturação por cálcio apresentou correlação muito fraca com o primeiro eixo, entretanto, com o segundo eixo de ordenação, foi muito forte. No diagrama de ordenação das parcelas, os quatro grupos florísticos foram discriminados em setores diferentes do diagrama, reforçando a visualização dos mesmos como hábitats bem definidos e com composição de espécies particular, resultando em clara separação das quatro classes de solo identificadas previamente. A análise de regressão logística comprovou os resultados obtidos da CCA, em relação às variáveis ambientais que determinaram a distribuição das espécies indicadoras dos grupos florísticos nas comunidades estudadas.

L’étude de la flore et de la végétation des clairières sur sol hydromorphe a été menée dans le Parc National de l’Ivindo au Nord-est du Gabon. La méthode phytosociologique de Braun-Blanquet (1932) a été retenue pour la réalisation des relevés au sein des deux principales formations végétales qui composent ce biotope: la prairie et la lisière qui la ceinture. Cent trente trois relevés ont permis de recenser 229 espèces réparties en 175 genres et 72 familles. Les matrices formées à partir de ces relevés et de ces espèces ont été analysées par la méthode Indicator Value (IndVal) ;des analyses canoniques redressées (DCA) et des analyses canoniques des correspondances (CCA) ont servi pour les ordinations. Des analyses de variance (ANOVA) suivies des tests post hoc de Bonferonni ont permis de voir si les valeurs des paramètres environnementaux et structuraux mesurés au sein des différents groupes sont différentes. <p>La flore globale des clairières est dominée par les Cyperaceae, les Rubiaceae et les Leguminosae-Caesalpinoideae. Cinq espèces (Fuirena stricta subsp. stricta, Pycreus subtrigonus, Pycreus mundtii, Rhynchospora perrieri et Leptochloa coerulecens) sont signalées pour la première fois au Gabon. <p>Huit groupements sont décrits: 5 pour les prairies et 3 au niveau des lisières. Quatre des groupements des prairies (le groupement pélophyte semi-aquatique à Costus afer et Centotheca lappacea ;le groupement hélophyte semi-aquatique à Pycreus mundtii et Pycreus subtrigonus ;le groupement pélophyte semi-aquatique à Virectaria multiflora et Kyllinga pumila ainsi que le groupement nitrophyte à Tristemma leiocalyx et Bacopa crenata) appartiennent à la classe des Phragmitetea tandis que le dernier (le groupement aquatique à Schoenoplectus mucronatus et Nymphaea heudelotii) se rattache à la classe des Potametea.<p>Deux des groupements de lisières (le groupement pélophyte pré-forestier à Ludwigia africana et Nephrolepis bisserata; le groupement hygrophyte des forêts marécageuses à Anthocleista schweinfurthii et Uapaca guineensis) appartiennent à la classe des Mitragynetea et le dernier (le groupement nitrophyte pré-forestier marécageux à Leptochloa coerulescens et Echinochloa indica) à celle des Phragmitetea. <p>L’hydromorphie et la profondeur de la vase ainsi que la fréquentation animale constituent les variables environnementales qui influencent significativement le déterminisme de ces groupements au sein des prairies, alors que ces variables n’ont aucun effet sur les groupements de lisière. <p>La richesse spécifique varie de 62 à 164 pour les groupements de lisière tandis qu’au sein des prairies, elle varie de 35 à 63. Les indices de diversité moyens pour l’ensemble des groupements des clairières sont 4,4 ± 0,5 (Shannon), 0,07 ± 0,03 (Simpson) et l’équitabilité de Piélou est de 0,78 ± 0,05. <p>La flore étudié n’est inféodée aux clairières du Gabon, les espèces endémiques guinéo-congolaises sont dominantes au niveau des lisières alors que ce sont les espèces à large distribution qui prédominent dans les prairies. Les géophytes et des thérophytes dominent dans les prairies tandis que les phanérophytes sont dominants dans les lisières. La zoochorie et l’anémochorie constituent les modes de dissémination les plus rencontrés au sein de la flore étudiée. <p>Mots clés :clairière intraforestière, flore, groupements végétaux, phytosociologie, Gabon.<p>Abstract<p>The study of the flora and the vegetation of the swampy clearings on hydromorphic soils were realized in the National Park of Ivindo in north-eastern of Gabon. The phytosociological method of Braun-Blanquet was adopted for the realization of the relevés within the two principal vegetation type which form this biotope: the central meadow and the edge which girdles it. 133 relevés made it possible to count 229 species divided into 175 genera and 72 families. The matrices made starting from these relevés and of these species were analyzed by the method Ind Val; DCA made it possible to obtain groupings; CCA made it possible to evaluate the environmental link between parameter and the vegetation. An analysis of variance (ANOVA) follow-up of the tests post hoc of Bonferonni made it possible to see whether the values measured within the various groups are different.<p>The flora is dominated by Cyperaceae, Rubiaceae and Leguminosae-Caesalpinoideae. Five species, Fuirena stricta subsp stricta, Pycreus subtrigonus, Pycreus mundtii, Rhynchospora perrieri and Leptochloa coerulescens are announced for the first time to Gabon.<p>Eight associations are described: 5 for the meadows and 3 on the level of the edges. Four of the associations of the meadows (the pelophyte semi-aquatic association with Costus afer and Centotheca lappacea; the helophyte semi-aquatic association with Pycreus mundtii and Pycreus subtrigonus; the pelophyte semi-aquatic association with Virectaria multiflora and Kyllinga pumila; the nitrophyte association with Tristemma leiocalyx and Bacopa crenata) belong to the class of Phragmitetea while the last (the aquatic association with Schoenoplectus mucronatus and Nymphaea heudelotii) is belong to the class of Potametea .<p>Two of the associations of edges (the pelophyte pre-forester association with Ludwigia africana and Nephrolepis bisserata; the hygrophyte association of the marshy forests with Anthocleista schweinfurthii and Uapaca guineensis) belong to the class of Mitragynetea and the third (the nitrophyte marshy pre-forester association with Leptochloa coerulescens and Echinochloa indica) to Phragmitetea. <p>The hydro-morphology and the depth of the mud as well as the animal frequentation constitute the environmental variables which influence the occurrence of these associations within the meadows, whereas they do not have any effect on the association edge.<p>The species richness varies from 62 to 164 for the association edge while within the meadows it varies from 35 to 63. The average indices of diversity for the whole of the associations of the clearings are 4.4 ± 0.5 (Shannon), 0.07 ± 0.03 (Simpson) while Piélou’s evenness is 0.78 ± 0.05.<p>The flora is not uniquely linked with the clearings of Gabon, although, on the phytogeographical level, the guineo-congolian endemics are dominant on the level of the edges whereas in fact the species with broad distributions prevail in the meadows. The analysis of the biological types shows the preponderance of the geophytes and the therophytes for the meadows while the edges are largely dominated by phanérophytes. The zoochory and the anemochory constitute the modes of dissemination most met within the studied flora.<p>Key words: Swampy clearings on hydromorphic soils, flora, association, phytosociology, forest clearings, Gabon.<p><p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished