Este trabalho discute a variabilidade dos fluxos de energia à superfície e de CO2 sobre uma área de Cerrado Sensu stricto no interior de São Paulo, e de uma área de ecótono Floresta-Cerrado (sazonalmente alagável) no Estado do Tocantins. Foram utilizadas medidas micrometeorológicas médias de 30 min, do clima (temperatura e umidade do ar, precipitação, velocidade do vento), dos fluxos de radiação (solar, PAR, saldo de radiação) e fluxos turbulentos de calor sensível, latente e CO2, coletadas no Cerrado durante o período de 2001 a 2003, e no ecótono durante Outubro de 2003 a Setembro de 2004. O ecótono e o Cerrado estão sob solos arenosos, homogêneos, com alta capacidade de infiltração e baixa de armazenamento. O Cerrado s.s. mostrou-se um ecossistema com forte sazonalidade da capacidade fotossintética, do Albedo-PAR e dos fluxos atmosféricos de CO2. Há uma fase de sumidouro e outra de fonte de CO2, corroborando os dados da literatura. Na escala da variabilidade interanual, as variações dos estados funcionais do Cerrado, como sumidouro ou fonte de CO2, foram fortemente dependentes das variações da precipitação e da temperatura mínima. No ecótono Floresta-Cerrado, a fase de inundação induz à uma diminuição gradual da respiração do sistema e da produtividade primária. A diminuição na produtividade ocorre com um atraso de ~45 dias, que poderia ser um tempo de assimilação e tolerância do sistema ao estresse induzido por anóxia. A redução da respiração do ecossistema ocorre ao passo que no regime alagado as perdas de CO2 ocorrem por evasão da superfície de água livre, um processo que aparentemente tem uma fonte de emissão menor que os processos de respiração do solo em condições secas. Durante a maior parte da inundação o ecótono continua a manter-se como um sumidouro de CO2 atmosférico durante, ao menos, 3 meses. O parâmetro RUE do ecótono foi cerca de 5 vezes maior do que o do Cerrado. A diferença de eficiência se deve possivelmente ao maior índice de área foliar das formações florestais da transição Floresta-Cerrado. A funcionalidade é controlada por fatores ambientais de maior escala que as locais. No caso do Cerrado s.s. há uma forte dependência do regime de chuvas e da temperatura mínima. No caso do ecótono Floresta-Cerrado, a suscetibilidade parece ser uma função do tempo de inundação. / This work discusses the energy and CO2 flux variability over a Cerrado Sensu stricto, in São Paulo state, Brazil, and over a seasonally inundated Forest-Cerrado ecotone in Tocantins state, Brazil. Micrometeorological measurements (30 minute average) of weather (temperature, relative humidity, precipitation and wind speed), radiation fluxes (solar radiation, PAR and net radiation), and CO2, latent and sensible heat turbulent fluxes were made for the Cerrado from 2001 to 2003. Measurements for the ecotone were made from October 2003 to September 2004. Both environments have sandy, homogeneous soils, with high infiltration capacity and low water storage. Cerrado s.s. showed strong seasonality for photosynthetic capacity, Albedo-PAR and CO2 atmospheric fluxes. As seen in other works, the Cerrado has both a CO2 sink and a CO2 source phase. These are strongly dependent on the precipitation and minimal temperature. Inundation of the Forest-Cerrado ecotone results in a gradual decrease in the system’s respiration and primary productivity. A lag of approximately 45 days is seen in the primary productivity reduction. This could represent the system’s resistance and tolerance due to anoxia stress. Ecosystem respiration in the inundated period is lower than in the dry period, apparently due to the lower CO2 outflux from the free water surface, in comparison with the CO2 flux from the soil. During most of the inundation period, the ecotone acts as a sink for CO2, for at least 3 months. The RUE for the ecotone was proximately 5 times higher than the Cerrado. This is probably due to the higher leaf area index of the forest area in the ecotone. The functionality of both biomes is controlled by larger scale environmental factors, as opposed to local factors. The Cerrado s.s. has a strong dependence precipitation and minimal temperature. The Forest-Cerrado ecotone shows a high dependence on the length of the inundated period.

A interação entre plantas e seus visitantes florais forma uma rede de interação complexa. Essa rede de interação possui propriedades emergentes que caracterizam a estrutura da rede. A composição, a riqueza e o papel das espécies nas redes de interação podem variar espaço-temporalmente e levar a alteração na estrutura das redes. A estrutura também pode variar de acordo com o grau de dependência entre os pares de espécies. É esperado que interações com elevado grau de dependência mútua variem menos no tempo e no espaço. A interação entre as plantas produtoras de óleo floral e as abelhas coletoras de óleo é de alta dependência mútua, já que as abelhas necessitam do óleo para alimentar as larvas e construir ninhos e são polinizadores mais importantes dessas plantas. O alimento larval destas abelhas é composto por pólen, óleo e néctar. A quantidade de alimento disponível para as larvas pode influenciar o tamanho dos adultos quando emergirem. As espécies de abelhas coletoras de óleo são solitárias, ou seja, não existe contato entre as gerações. Assim uma abelha recém-emergida deve ser capaz de encontrar as fontes de óleo, seguindo algum sinal de atração, que poderia ser através de odores voláteis. No presente trabalho analisamos se a estrutura da rede de interação formada pelas plantas produtoras de óleo floral e seus visitantes coletores de óleo varia espacialmente e temporalmente. Para a análise temporal coletamos dados da interação por dois anos em Itirapina, São Paulo. No estudo de variação espacial comparamos as redes de interação em cinco áreas de cerrado no interior de São Paulo. Em ambos os estudos usamos métricas de redes complexas. Além disso, estudamos a relação entre tamanho de célula de cria e quantidade de alimento disponível para as larvas e tamanho das abelhas adultas ao emergirem, para uma espécie de abelha coletora de óleo: Tetrapedia diversipes. Para isso medimos abelhas e suas células de cria e relacionamos estas medidas. Também manipulamos a quantidade de alimento disponível para as larvas e medimos os adultos emergidos. Por fim, procuramos odores voláteis em Byrsonima intermedia. Coletamos odores voláteis com a técnica de dynamic headspace. Analisamos as coletas com GCMS. A estrutura da rede de interação entre as plantas produtoras de óleo floral e as abelhas coletoras de óleo variou espaço-temporalmente. A análise temporal mostrou que o grau de especialização da rede foi fortemente alterado entre os anos de estudo e que a abundância foi um fator importante para explicar a ocorrência das interações. As espécies que tiveram suas abundâncias alteradas entre os anos também tiveram alteração no número de interações. Na análise espacial observamos que as interações e as espécies compartilhadas entre os locais de estudo foram aquelas com maior grau de interação (generalista). Além das interações e espécies generalistas se manterem nas cinco localidades, as espécies generalistas sustentam as espécies localmente raras. Byrsonima intermedia foi considerada uma espécie super-generalista nas cinco redes analisadas e 77% das interações compartilhadas envolveram esta espécie. A morfometria dos indivíduos de Tetrapedia diversipes estudados foi positivamente correlacionada com o volume da célula de cria e a quantidade de alimento. Quando relacionamos o volume das células de cria com as medidas corpóreas das abelhas verificamos que as abelhas maiores emergiram em células maiores. No entanto essa relação foi fraca. Após o experimento de manipulação de alimento verificamos que as abelhas emergidas de células sem manipulação foram maiores que as abelhas que tiveram o alimento retirado, e que entre as abelhas manipuladas aquelas que receberam mais alimento foram maiores. Nós não encontramos odores voláteis em flores de Byrsonima intermedia. / The plant pollinator interaction forms a complex network. These networks have emergent properties that characterize the structure of network. The number, identity and species role of the network may vary spatio-temporally and lead to changes in the structure of the networks. Moreover, the structure may vary according to the dependence degree of the interacting pairs. It is expected that interactions with a high mutual dependence degree are more stable. The interaction between oil producing plants and oil collecting bees is highly mutual dependence, since bees need oil to feed the larvae and are pollinators of these plants. The larval diet consists of pollen and oil/nectar. The amount of food available to the larvae may influence the adults size. The oil collecting bees are solitary, i.e., there is no contact between generations. Thus, a naive emerged bee should be able to find the oil plants, using some attractive cues that could be volatile odor. In this work we want to answer if the network structure of the interaction between oil producing plants and oil collecting bees varies spatially and temporally. For the temporal analysis we carried out field work for two years at Itirapina, São Paulo. In the study of spatial variation we compare interaction networks in five areas of cerrado. In both studies we use metrics of complex networks. Furthermore, we studied the relation between size of adult bees (Tetrapedia diversipes) and brood cell sizes and the amount of food available for the larvae. We measured the bees and their brood cells and relate it. Also we manipulated the amount of food available for the larvae and we took measures of the adults. Finally, we search for volatile odors in Byrsonima intermedia. We collect volatile odors with the technique of dynamic headspace. We analyzed the samples with GCMS. The network structure of interaction between oil producing plants and oil collecting bees varied spatio-temporally. The temporal analysis showed that the specialization degree of the network changed between the years and that the abundance has a key role to explain the occurrence of interactions. Species that had changed their abundances between years were also changed in the number of interactions. Spatial analysis found out that the interactions and species ubiquitous among the study sites were those that had the greatest interaction degree (generalist specie). Moreover, generalist species maintain the locally rare species. Byrsonima intermedia was regarded a super-generalist specie in the five networks analyzed and 77% of ubiquitous interactions involved this species. The morphometry of Tetrapedia diversipes individuals was positively correlated with the volume of the brood cells and the amount of food. When relating the volume of brood cells with measures of bees we found that larger bees emerged in larger cells. However this relationship was weak. The experiment of handling food showed that bees emerged from control cells were larger than bees that had the food removed, and between the manipulated bees those who received more food became bigger. We did not detect volatile odors in flowers Byrsonima intermedia.

Deforestation of the Brazilian savanna (Cerrado) region has caused major changes in hydrological processes. These changes in water balance and soil erosion are still poorly understood, but are important for making land management decisions in this region. Therefore, it is necessary to understand the magnitudes of hydrological processes and soil erosion changes on local, regional and continental scales, and the consequences that are generated. The main objective of the study presented in this doctoral thesis was to better understand the mechanism of hydrological processes and soil erosion in the Cerrado. To achieve that, I worked with different scales (hillslope, watershed and continental) and using data from experimental field, laboratory, and remote sensing. The literature review reveals that the annual rainfall erosivity in Brazil ranges from 1672 to 22,452 MJ mm ha-1 h-1 yr-1. The smallest values are found in the northeastern region, and the largest in the north and the southeastern region. I found that the canopy interception may range from 4 to 20% of gross precipitation and stemflow around 1% of gross precipitation in the cerrado. The average runoff coefficient was less than 1% in the plots under cerrado and that the deforestation has the potential to increase up to 20 fold the runoff coefficient value. The results indicate that the Curve Number method was not suitable to estimate runoff under undisturbed Cerrado, bare soil (hydrologic soil group A), pasture, and millet. Therefore, in these cases the curve number is inappropriate and the runoff is more aptly modeled by the equation Q = CP, where C is the runoff coefficient. The water balance from the remote sensing data across the Brazilian Cerrado indicates that the main source of uncertainty in the estimated runoff arises from errors in the TRMM precipitation data. The water storage change computed as a residual of the water budget equation using remote sensing data (TRMM and MOD16) and measured discharge data shows a significant correlation with terrestrial water storage change obtained from the GRACE data. The results show that the GRACE data may provide a satisfactory representation of water storage change for large areas in the Cerrado. The average annual soil loss in the plots under bare soil and cerrado were 15.25 t ha-1 yr-1 and 0.17 t ha-1 yr-1, respectively. The Universal Soil Loss Equation cover and management factor (C-factor) for the plots under native cerrado vegetation was 0.013. The results showed that the surface runoff, soil erosion and C-factor for the undisturbed Cerrado changes between seasons. The greatest C-factor values were found in the summer and fall. The results found in this doctoral thesis provide benchmark values of the water balance components and soil erosion in the Brazilian Cerrado that will be useful to evaluate past and future land cover and land use changes for this region. In addition, I conclude that the remote sensing data are useful to evaluate the water balance components over Cerrado regions, identify dry periods, and assess changes in water balance due to land cover and land use change. / O desmatamento nas regiões de Cerrado tem causado intensas mudanças nos processos hidrológicos. Essas mudanças no balanço hídrico e erosão do solo são ainda pouco entendidas, apesar de fundamentais na tomada de decisão de uso e manejo do solo nesta região. Portanto, torna-se necessário compreender a magnitude das mudanças nos processos hidrológicos e de erosão do solo, em escalas locais, regionais e continentais, e as consequências dessas mudanças. O principal objetivo do estudo apresentado nesta tese de doutorado foi de melhor entender os mecanismos dos processos hidrológicos e de erosão do solo no Cerrado Brasileiro. Para tanto, utilizou-se diferentes escalas de trabalho (vertentes, bacias hidrográficas e continental) e usando dados experimentais in situ, de laboratório e a partir de sensoriamento remoto. O estudo de revisão de literatura indica que a erosividade da chuva no Brasil varia de 1672 to 22,452 MJ mm ha-1 h-1 yr-1. Os menores valores encontram-se na região nordeste e os maiores nas regiões norte e sudeste do Brasil. Verificou-se que os valores de interceptação da chuva variam de 4 a 20% e o escoamento pelo tronco aproximadamente 1% da precipital total no cerrado. O coeficiente de escoamento superficial foi menor que 1% nas parcelas de cerrado e o desmatamento tem o potencial de aumentar em até 20 vezes esse valor. Os resultados indicam que o método Curve Number não foi adequado para estimar o escoamento superficial nas áreas de cerrado, solo exposto (grupo hidrológico do solo A), pastagem e milheto. Portanto, nesses casos o uso do CN é inadequado e o escoamento superficial é melhor estimado a partir da equação Q = CP, onde C é o coeficiente de escoamento superficial. O balanço hídrico a partir de dados de sensoriamento remoto para todo o Cerrado Brasileiro indica que a principal fonte de incerteza na estimativa do escoamento superficial ocorre nos dados de precipitação do TRMM. A variação de água na superfície terrestre calculada como o residual da equação do balanço hídrico usando dados de sensoriamento remoto (TRMM e MOD16) e valores observados de vazão mostram uma correlação significativa com os valores de variação de água na superfície terrestre provenientes dos dados do GRACE. Os dados do GRACE podem representar satisfatoriamente a variação de água na superfície terrestre para extensas regiões do Cerrado. A média anual de perda de solo nas parcelas de solo exposto e cerrado foram de 15.25 t ha-1 yr-1 and 0.17 t ha-1 yr-1, respectivamente. O fator uso e manejo do solo (fator C) da Universal Soil Loss Equation para o cerrado foi de 0.013. Os resultados mostraram que o escoamento superficial, erosão do solo e o fator C na área de cerrado variam de acordo com as estações. Os maiores valores do fator C foram encontrados no verão e outono. Os resultados encontrados nesta tese de doutorado fornecem valores de referência sobre os componentes do balanço hídrico e erosão do solo no Cerrado, que podem ser úteis para avaliar o uso e cobertura do solo atual e futuro. Além disso, conclui-se que os dados de sensoriamento remoto apresentam resultados satisfatórios para avaliar os componentes do balanço hídrico no Cerrado, identificar os períodos de seca e avaliar as alterações no balanço hídrico devido à mudanças de uso e cobertura do solo.

The Jiroft valley, in southeastern Iran, was an important agricultural centre since the Early Bronze Age (3rd millennium BCE). The valley is characterized by harsh environmental settings: hot climate with poor rainfall. However, more optimal conditions may have prevailed earlier that supported ancient settlements. A 250-cm sediment core was retrieved from a peat-land at Konar Sandal, a major archaeological find attributed to Jiroft culture. The palynological data from this core was combined with geochemical and sedimentological proxies aimed at establishing the human-environment interactions in the area. The study focus was directed at vegetation history and landscape evolution, hydroclimatic changes and past human activities, that started just after the projected collapse of the Jiroft (4 ka) and extended all the way from the late Bronze Age to the Mongol invasion (0.6 ka). The results indicate that the valley was dominated by Saharo-Sindian open pseudo-savannah vegetation for the last 4000 years. However, due to anthropogenic clearance and intensified agro-pastoral activities, and also climatic factors, the land cover shifted from open xeric scrubland forests to more open, degraded landscapes. The principal human practice in these early settlements was cereal cultivation. But it is likely that during the more arid periods, communities retreated and abandoned agriculture, facilitating successional processes. Such droughts occurred in 4-3.8 ka and 3.4-2.8 ka and were supported by palynological data, C/N and Fe2O3 content. Peat formation was characteristic to the wetland during these arid periods. These droughts corresponded to drought phases detected in other studies, and were attributed to changes in Siberian Anticyclones. Dynamics of Artemisia and desert shrubs indicate milder climate around 3.8-3.4 ka and 2.8-0.6 ka. In the latter episode, during the rule of Persian Empire (ca. 550 BCE-650 CE) and Islamic epoch, the highest vegetation degradation state and most intensive human activities were observed. Some inconspicuous human practices, such as date cultivation, may have occurred on site as an adaptation to extreme environmental conditions. / High-resolution paleolimnological records from Lake Jazmurian: Climate-culture evolution at Jiroft in southeast Iran during the Holocene

The structuring of ant assemblages in a Southern African savanna was investigated using data from the only long-term, large-scale savanna fire experiment in Africa. A comprehensive survey of three habitats in the Kruger National Park (KNP) revealed a total of 169 ant species from 41 genera. The sampling efficiency and consistency of pitfall traps and Winkler samples for inventory, bioindicator and ecological studies in savanna habitats was compared using ants. Pitfall traps were more efficient and productive than Winkler sampling for epigaiec ants, with a greater total species richness and higher abundance of ants recorded. Suggestions were made to improve Winkler sampling output, and to allow quantitative data to be collected. With the structuring of local assemblages, competition was the most significant local factor tested. The relationship between ant dominance and ant species richness was consistent across three continents. A model developed to test mechanisms that could be responsible for the form of this relationship supported the hypothesis that competitive exclusion by dominant ants at least partially reduces species richness. Stress was only partially responsible for low dominance and low species richness, while scatter in the data points is related to patchiness of ants at baits. These findings contrast strongly with previous claims regarding the relationship between richness and dominance. Habitat complexity was not found to play an important role in determining ant assemblage body size in this savanna system. The size-grain hypothesis (Kaspari&Weiser 1999) which predicts that environmental rugosity results in positive allometric scaling of leg length on body length because of changes in locomotion costs, was tested by comparing the body sizes of ants from areas of contrasting habitat complexity. No support for the hypothesis was found. Phylogenetic independent contrast methods did however support the allometric relationship found by Kaspari and Weiser (1999). Ant assemblages in KNP exhibited a remarkable degree of resistance, and in some cases resilience, to burning. Species richness or abundance did not vary with different burning treatments, although ant assemblage composition was sensitive to burning treatment. This difference, however, was only pronounced between burnt and unburnt plots, not between burning treatments. The degree of response of ant assemblages is likely to be related to two main contributory factors: mean annual rainfall and changes in vegetation structure with burning, and the assemblage's history of association with fire. An overview of published research on the effects of fire on fauna in Southern Africa was undertaken. Few studies have examined the effects of fire on amphibians or reptiles and few experimental studies have been undertaken using an experimental fire regime applied over appropriately long time intervals. Most studies provided no information on the scale of the study. Replication was often not reported, and was generally inadequate. Information on the effects of fire on fauna in Southern Africa is fragmentary, and consequently informed management decisions regarding the consequences of burning policies on the conservation of biodiversity both within and outside protected areas are problematic. Recommendations and suggestions for improving fire research are given. / Thesis (DPhil (Zoology))--University of Pretoria, 2005. / Zoology and Entomology / unrestricted

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The proposal project is designing the development plan of the ZOO in Dvur Kralove nad Labem, as has designed a new exhibition of new lions, hyenas, birds of prey, the African desert and the object of refreshments for visitors. Architectural study addresses the design of objects - pavilions exposure for lions, hyenas, a pavilion with an aviary for birds of prey - bird world, the African pavilion terrarium desert and finally building with a cafe and toilets for the visitors of the ZOO. The proposed approach also runs the individual pavilions, then runs for the lions and hyenas and near runs in the African desert ungulates and seasonal runs. The proposed solution recognizes the zoo premises as a place for keeping large animal species composition, education of visitors, as the meeting place of rest and relaxation. The solution takes into account the complex relationships and interactions between exposures in a given area, not only in terms of architectural and aesthetic approach to the complex, but also in terms of operating and zoological.The zoo is a park with specific exposure to live with a balanced human rights - a visitor to one side and kept the animal on the other.  The proposed solution to the Zoo is sensitive to the surrounding landscape, the existing urban and architectural design and space requirements for any award.  From an operational point of view, the proposal accepted by all the requirements of the future. Areas and facilities for public service facilities, paddocks and animal quarters are each precisely defined and strictly separated geographically and operationally. Are the optimal conditions for the movement of animals between quarters and corral. The proposed solution is very rich in variety of areas, which in addition to the versatility of targeted animals, reflected in the richness of flora and fauna and thus contributing to environmentally high value sites. All spaces is a common need a sufficient level of daylight and direct sunlight. The entire area surrounding the exposure and access roads are designed to completely wheelchair accessible and accessible for persons with reduced mobility. The proposed solution to a sensitive development of existing space is achieved by a better, easier and easier availability. Term solutions proposed pavilions, yards and access roads is based on the themes of African villages. Small scale architectural and mutual spatial composition of individual materials of the new pavilions interconnected units reflects the typical mass breakdown of urban structures in the original locations of breeding species. Pavilions and animal quarters, and appropriately use the added space in the area of ??the zoo and complete the overall character of the place in the context of the current solution to urban zoo.

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The savannas of southern Africa are a highly variable and globally-important biome supporting rapidly-expanding human populations, along with one of the greatest concentrations of wildlife on the continent. Savannas occupy a fifth of the earth's land surface, yet despite their ecological and economic significance, understanding of the complex couplings and feedbacks that drive spatiotemporal patterns of change are lacking. In Chapter 1 of my dissertation, I discuss some of the different theoretical frameworks used to understand complex and dynamic changes in savanna structure and composition. In Chapter 2, I evaluate spatial drivers of water quality declines in the Chobe River using spatiotemporal and geostatistical modeling of time series data collected along a transect spanning a mosaic of protected, urban, and developing urban land use. Chapter 3 explores the complex couplings and feedbacks that drive spatiotemporal patterns of land cover (LC) change across the Chobe District, with a particular focus on climate, fire, herbivory, and anthropogenic disturbance. In Chapter 4, I evaluated the utility of Distance sampling methods to: 1) derive seasonal fecal loading estimates in national park and unprotected land; 2) provide a simple, standardized method to estimate riparian fecal loading for use in distributed hydrological water quality models; 3) answer questions about complex drivers and patterns of water quality variability in a semi-arid southern African river system. Together, these findings have important implications to land use planning and water conservation in southern Africa's dryland savanna ecosystems. / Ph. D.