This thesis examines how early warning signals perform when tested on climate systems thought to exhibit future tipping point behaviour. A tipping point in a dynamical system is a large and sudden change to the state of the system, usually caused by changes in external forcing. This is due to the state the system occupies becoming unstable, causing the system to settle to a new stable state. In many cases, there is a degree of irreversibility once the tipping point has been passed, preventing the system from reverting back to its original state without a large reversal in forcing. Passing tipping points in climate systems, such as the Amazon rainforest or the Atlantic Meridional Overturning Circulation, is particularly dangerous as the effects of this will be globally felt. Fortunately there is potential for early warning signals, designed to warn that the system is approaching a tipping point. Generally, these early warning signals are based on analysis of the time series of the system, such as searching for ‘critical slowing down’, usually estimated by an increasing lag-1 autocorrelation (AR(1)). The idea here is that as a system’s state becomes less stable, it will start to react more sluggishly to short term perturbations. While early warning signals have been tested extensively in simple models and on palaeoclimate data, there has been very little research into how these behave in complex models and observed data. Here, early warning signals are tested on climate systems that show tipping point behaviour in general circulation models. Furthermore, it examines why early warning signals might fail in certain cases and provides prospect for more ‘system specific indicators’ based on properties of individual tipping elements. The thesis also examines how slowing down in a system might affect ecosystems that are being driven by it.

A variety of aquatic habitats with different levels of potential predators are available to larval amphibians in Central Amazon rainforest. The anuran community at Reserva Florestal Adolfo Ducke, 25 km east of Manaus, Amazonas, Brasil, was studied to determine which species have eggs and/or larvae in water and how those larvae are distributed in time and space. The temporal and spatial distribution of potential predators as well as abiotic characteristics of these waterbodies were determined simultaneously to test for correlations with the distribution of tadpoles. The distribution of tadpoles was strongly related to fish predation pressure. Several tadpole species were found only in waterbodies with high fish abundance and thus have the ability to survive with fish. Most of these tadpoles were found to be unpalatable in controlled experiments. Unpalatability is the major adaptation allowing the coexistence of tadpoles and fish and is thus a major factor affecting tadpole community composition in this system. Controlled experiments showed that fish do not eat anuran eggs while the tadpoles of Leptodacrylus knudseni and Osteocephalus taurinus ate all types of eggs offered. The percentage of anurans with aquatic oviposition was positively related to fish abundance and negatively related to the occurrence of species of tadpole that ate eggs in experiments. These findings suggest that the present patterns of anuran distribution represent an evolutionary response to predation on the eggs and larvae. Contrary to the models of Heyer et al. (1975) and Wilbur (1984), desiccation and predation-pressure were not the major factors affecting species richness within waterbodies of the RFAD rainforest. In support of the model of Heyer et al. (1975), anuran species richness was correlated with the size of the waterbody. This could be because the size of the waterbody is related to increased complexity and availability of microhabitats. The range of volumes of waterbodies was also found to directly affect species richness of the RFAD community. While predation appeared to have a limited effect on species richness of individual ponds, predation-pressure was found to have a major influence on species composition. Anuran eggs and larvae survived with specific predators by possessing particular survival-traits (e.g. unpalatability and oviposition strategies). However, survival-traits were not effective against all predators in all habitats. The distribution of different predators among ponds provides a patchy environment on a local scale (i.e. within ponds). When combined with the variety of survival-traits exhibited by the anuran species, this spatial patchiness in predation contributes towards species richness within the anuran community of the RFAD rainforest.

<p>Amazonia contains the largest remaining tracts of undisturbed tropical forest on earth, and is thus critical to international nature conservation and carbon sequestration efforts. Amazonian forests are notoriously difficult to study, however, due to their species richness and inaccessibility. This has limited efforts to produce the accurate, high-resolution biodiversity maps needed for conservation and development. The aims of the research described here were to identify efficient solutions to the problems of tropical forest inventory; to use these methods to identify floristic patterns and their causes in western Amazonia; and propose new means to map floristic patterns in these forests.</p><p> Using tree inventories in the vicinity of Iquitos, Peru, I and a colleague systematically evaluated methods for rapid tropical forest inventory. Of these, inventory of particular taxonomic groups, or taxonomic scope inventory, was the most efficient, and was able to capture a majority of the pattern observed by traditional inventory techniques with one-fifth to one-twentieth the number of stems and species. Based on the success of this approach, I and colleagues specifically evaluated two plant groups, the Pteridophytes (ferns and fern allies) and the Melastomataceae (a family of shrubs and small trees), for use in rapid inventory. Floristic patterns based on inventories from either group were significantly associated with those based on the tree flora, and inventories of Pteridophytes in particular were in most cases able to capture the majority of floristic patterns identified by tree inventories. These findings indicate that Pteridophyte and Melastomataceae inventories are useful tools for rapid tropical forest inventory.</p><p> Using Pteridophyte and Melastomataceae inventories from 138 sites in northwestern Amazonia, combined with satellite data and soil sampling, I and colleagues studied the causes of vegetation patterns in western Amazonian forests. On the basis of these data, we identified a floristic discontinuity of at least 300km in northern Peru, corresponding to a 15-fold difference in soil cation concentrations and an erosion-generated geological boundary. On the basis of this finding, we assembled continent-scale satellite image mosaics, and used these to search for additional discontinuities in western Amazonia. These mosaics indicate a floristic and geological discontinuity of at least 1500km western Brasil, driven by similar erosional processes identified in our study area. We suggest that this represents a chemical and ecological boundary between western and central Amazonia.</p><p> Using a second network of 52 pteridophyte and soil inventories in northwestern Amazonia, we further studied the role of geology in generating floristic pattern. Consistent with earlier findings, we found that two widespread geological formations in western Amazonia differ eight-fold difference in soil cation concentrations and in a majority of their species. Difference in elevation, used as a surrogate for geological formation, furthermore explained up to one-third of the variation in plant species composition between these formations. Significant correlations between elevation, and cation concentrations and soil texture, confirmed that differences in species composition between these formations are driven by differences in soil properties. On the basis of these findings, we were able to use SRTM elevation data to accurately model species composition throughout our study area.</p><p> I argue that Amazonian forests are partitioned into large-area units on the basis of geological formations and their edaphic properties. This finding has implications for both the ecology and evolution of these forests, and suggests that conservation strategies be implemented on a region-by-region basis. Fortunately, the methods described here provide a means for generating accurate and detailed maps of floristic patterns in these vast and remote forests.</p> / Dissertation

Tree squirrels play an important role in the maintenance of forest ecosystems by functioning as seed and fungal spore dispersers, forest regenerators, and prey for forest predators. The highest species richness for tree squirrels occurs in tropical forests and these species are also the least studied. We conducted distance sampling to estimate population density, measured habitat variables to investigate forest characteristics that influence habitat selection and feeding site selection at three different scales, and conducted observations to obtain knowledge about activity pattern and behavior of Neotropical pygmy squirrels and Amazon red squirrels in the Peruvian Amazon. Density of Neotropical pygmy squirrels was 0.10 and 0.14 individuals/ha for 2009 and 2010. Activity peaked in early morning, squirrels were found mainly in the canopy but never on the ground, and frequency of behaviors differed by time and story level. Neotropical pygmy squirrels used mainly high and low restinga and areas that had more large trees. Squirrels also used species of trees disproportionately to availability. Neotropical pygmy squirrels seem to be associated with features related to mature forests. Amazon red squirrels use mainly high and low restinga and selected Astrocaryum and Attalea palm trees that were taller and larger as foraging sites compared to random locations. Amazon red squirrels used all vertical strata of the forest and the main behaviors observed were travel and forage. Behaviors were similar among time periods but differed in frequency by vertical strata. Although Amazon red squirrels used vegetation communities differently than their availability and selected for tree characteristics, they did not select for site characteristics and this is different from other tree squirrel species. We also conducted surveys during a wet and a dry year to investigate and estimate diversity of diurnal mammals. We assessed the vertical strata of the forest to determine if diversity index varied by story level, and estimated alpha, beta, and gamma diversity. Overall mammal diversity did not differ between wet and dry years. Diversity index differed by story level between years, but was the highest in the canopy for both years. Alpha diversity was higher in the dry year, and gamma and beta diversity were higher in the wet year. Frequency of sightings of species was influenced by time of day and varied by story level. Protection of continuous, mature forests with large canopies has important conservation implications as these areas most likely protect the greatest diversity of mammals while also providing shelter and food for other taxa.

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Submitted by Valquíria Barbieri (kikibarbi@hotmail.com) on 2018-04-19T19:02:18Z No. of bitstreams: 1 DISS_2015_Larissa Irene da Silva.pdf: 3830512 bytes, checksum: effa1f609c60aad498f2c09c31af4590 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2018-04-27T17:50:29Z (GMT) No. of bitstreams: 1 DISS_2015_Larissa Irene da Silva.pdf: 3830512 bytes, checksum: effa1f609c60aad498f2c09c31af4590 (MD5) / Made available in DSpace on 2018-04-27T17:50:29Z (GMT). No. of bitstreams: 1 DISS_2015_Larissa Irene da Silva.pdf: 3830512 bytes, checksum: effa1f609c60aad498f2c09c31af4590 (MD5) Previous issue date: 2015-08-27 / CNPq / As doenças infecciosas estão entre as dez principais causas de óbitos no mundo. Os produtos naturais são fontes importantes de antibióticos. Sendo assim este trabalho se propõe a avaliar a atividade antibacteriana, antioxidante e bioprospectar alguns metabólitos secundários de plantas de uso popular na região do Vale do Juruena, e microrregião do Norte Araguaia, Mato Grosso, Brasil. Uma amostra de cada planta foi depositada no depositadas no Herbário da UFMT e no HERBAM. Os extratos das 99 espécies foram obtidos por maceração em solução hidroetanólica a 70%. A atividade antimicrobiana foi avaliada pelo método microdiluição em caldo, pelo qual se determinou a concentração inibitória mínima (CIM). Claritromicina e anfotericina (0,39 - 50 μg/mL), foram utilizadas como padrões, bacterianos e fúngicos, respectivamente. A capacidade antioxidante foi determinada pelos ensaios de DPPH, FRAP e NO usando-se ácido ascórbico como padrão, e, para este último quercetina. Dois extratos hidroetanólicos destacaram-se pelo amplo espectro de atividade antibacteriana: Bauhinia glabra (EHBg) e Terminalia argentea (EHTa). O EHBg apresentou boa atividade antibacteriana frente à Klebsiella pneumoniae (CIM = 25 μg/mL), moderada frente a Enterococcus faecalis (CIM = 200 μg/mL) e Streptococcus pyogenes (CIM = 400 μg/mL) e fraca atividade contra Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Shigella flexneri, Staphylococcus epidermidis e Bacillus subtilis (CIM = 800 μg/mL). O EHTa apresentou moderada atividade contra Staphylococcus aureus (CIM = 200 μg/mL), Enterococcus faecalis, Streptococcus pyogenes, Staphylococcus epidermidis e Bacillus subtilis (CIM = 400 μg/mL). Dois extratos hidroetanólicos destacaram-se pelo amplo espectro de atividade antifúngico: Bertholletia excelsa (EHBe), Cochlospermum regium (EHCch)e Qualea grandiflora (EHQg). O EHBe apresentou moderada atividade contra Aspergillus terreus (CIM = 100 μg/mL), Aspergillus fumigatus (CIM = 200 μg/mL), Candida glabrata e Cryptococcus neoformans (CIM = 400 μg/mL), e fraca atividade contra Candida albicans e Candida tropicalis (CIM = 800 μg/mL).O EHCch apresentou boa atividade contra Penicillium verrucosum, Trichophyton mentagrophytes e Microsporum gypseum (CIM = 6,25 μg/mL), moderada contra Candida albicans, Candida albicans fluconazol-resistente, Aspergillus fumigatus (CIM = 400 μg/mL) e fraca contra Aspergillus niger, Aspergillus parasiticus e Aspergillus terreus (CIM = 800 μg/mL). O EHQg demonstrou boa atividade frente a Trichophyton rubrum (CIM = 12,5 μg/mL) e fraca atividade contra Candida albicans, Candida albicans fluconazol-resistente, Candida tropicalis e Cryptococcus neoformans, Aspergillus fumigatus, Aspergillus niger, Aspergillus parasiticus, e Aspergillus terreus (CIM = 800 μg/mL). Se destacaram pela sua atividade antioxidante, nos modelos de DPPH e FRAP, respectivamente, EHBe (CI50 = 0,39 ± 0,08 e 65,00 ± 8,67 μg/mL), Cariniana rubra (CI50 = 0,44 ± 016 E 64,00 ± 4,43 μg/mL) e Cedrela odorata (IC50 = 0,56 ± 0,08 and 56,37 ± 0,75μg/mL), nenhum extrato hidroetanólico testado exibiu CI no modelo de NO. Os teores de fenois totais nos extratos hidroetanólicos variaram de 0,06 a 10,91 mgEAt/g, os de flavonoides totais de 0,01 a 4,40 mgER/g e os de cumarinas, apresentarajm variação de 0,011 a 2,09 mgEC/g. Os resultados apontam a existência de componentes biológicamente ativos nas plantas medicinais da região do Vale do Juruena e microrregião no Norte Araguaia, ratificando seu o uso popular para o tratamento de infecções. Essas propriedades revelaram um grande potencial antimicrobiano e antioxidante dos extratos que poderiam ser aplicados futuramente na indústria farmacêutica, alimentar e cosmética. / Infectious diseases are among the ten leading causes of deaths worldwide. Natural products are important sources of antibiotics. Thus, this study aims to evaluate the antibacterial activity, antioxidant and bioprospect some secondary metabolites of popular use of plants in the region of the Juruena Valley and micro-region in North Araguaia, Mato Grosso, Brazil. A sample of each was deposited in deposited in the Herbarium of UFMT and HERBAM. The extracts of the 99 species were obtained by maceration in hydroethanol 70% solution. The antimicrobial activity was evaluated by the microdilution broth method by which it was determined the minimum inhibitory concentration (MIC), clarithromycin and amphotericin (0,39 - 50 μg/mL), were used as standards, bacterial and fungal, respectively. The antioxidant capacity was determined by DPPH, FRAP and NO using ascorbic acid as a standard, and for the latter quercetin. Two hydroethanolic statements highlighted by the broad spectrum of antibacterial activity: Bauhinia glabra (EHBg) and Terminalia argentea (EHTa). The EHBg showed good antibacterial activity against Klebsiella pneumoniae (MIC = 25 μg/mL), moderate against Enterococcus faecalis (MIC = 200 μg/mL) and Streptococcus pyogenes (MIC = 400 μg/mL) and weak activity against Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Shigella flexneri, Staphylococcus epidermidis e Bacillus subtilis (MIC = 800 μg/mL). The EHTa showed moderate activity against Staphylococcus aureus (MIC = 200 μg/mL), Enterococcus faecalis, Streptococcus pyogenes, Staphylococcus epidermidis e Bacillus subtilis (MIC = 400 μg/mL). Two hydroethanolic extracts highlighted by the broad spectrum of antifungal activity: Bertholletia excelsa (EHBe), Cochlospermum regium (EHCch) andd Qualea grandiflora (EHQg). The EHBe showed moderate activity against Aspergillus terreus (MIC = 100 μg/mL), Aspergillus fumigatus (MIC = 200 μg/mL), Candida glabrata and Cryptococcus neoformans (MIC = 400 μg/mL), and weak activity against Candida albicans and Candida tropicalis (MIC = 800 μg/mL). The EHCch showed good activity against Penicillium verrucosum, Trichophyton mentagrophytes and Microsporum gypseum (MIC = 6,25 μg/mL), moderate against Candida albicans, Candida albicans fluconazole-resistent, Aspergillus fumigatus (MIC = 400 μg/mL) and weak against Aspergillus niger, Aspergillus parasiticus and Aspergillus terreus (MIC = 800 μg/mL). The EHQg showed good activity against Trichophyton rubrum (MIC = 12,5 μg/mL) and weak against Candida albicans, Candida albicans fluconazole-resistent, Candida tropicalis and Cryptococcus neoformans, Aspergillus fumigatus, Aspergillus niger, Aspergillus parasiticus, and Aspergillus terreus (MIC = 800 μg/mL). Stood out for their antioxidant activity in models of DPPH and FRAP, respectively, EHBe (IC50 = 0,39 ± 0,08 e 65,00 ± 8,67 μg/mL), Cariniana rubra (IC50 = 0,44 ± 016 E 64,00 ± 4,43 μg/mL) and Cedrela odorata (IC50 = 0,56 ± 0,08 and 56,37 ± 0,75μg/mL), no hydroethanolic extract tested exhibited IC in the model. The total phenols content in hydroethanolic extracts ranged from 0,06 - 10,91 mgEAt/g, the total flavonoids 0,01 a 4,40 mgER/g and the coumarins showed variation from 0,011 - 2,09 mgEC/g. The results show the existence of biologically active components in medicinal plants Juruena Valley region and micro region in North Araguaia, confirming its popular use for the treatment of infections. These properties showed strong antimicrobial and antioxidant potential of extracts that could be applied in the future in the pharmaceutical, food and cosmetics.

As modificações do clima se apresentam como um dos maiores desafios da sociedade contemporânea, principalmente no que se refere aos seus efeitos no meio natural e na biodiversidade. Os riscos das alterações climáticas ainda não são totalmente conhecidos, e suas consequências para a diversidade biológica estão sendo descobertas no momento atual. Porém, seus impactos vão além das modificações no ambiente natural e se refletem também nas políticas e relações mundiais. Neste sentido, o presente trabalho analisa as inter-relações entre as políticas públicas de biodiversidade e de mudanças climáticas, nas diferentes escalas de atuação. O interesse é identificar como um problema de ordem mundial se desdobra em âmbito local. Para isso, avalia a situação das políticas que incidem na Amazônia brasileira, tendo como estudo de caso o mosaico formado pelo Parque Estadual e RPPN do Cristalino, localizados no Estado de Mato Grosso. / The climate change is one of the major challenges of contemporary society, especially regarding its effects on the nature environment and biodiversity. The risks of climate change is not well known yet, and its consequences for biodiversity are being discovered at the moment. However, its impacts are beyond the changes in the natural environment and are also reflected at the policies and global relations. So, this paper analyzes the interrelationships between public policies on biodiversity and on climate change, considering the different scales of operation. It aims to identify how a world order problem unfolds at the local level. Thus, it verifies the situation of the public policies that impact on the brazilian Amazon, which the case study is the mosaic formed by the Parque Estadual e RPPN do Cristalino, located in Mato Grosso.

This dissertation examines representations of the forest in Canadian and Brazilian literatures and cultural imaginaries in order to question utilitarian models of environmental use and discuss issues of deforestation in both countries. I argue that these models draw on aesthetic and narrative strategies that were consolidated through cultural myths about the Canadian woods and the Brazilian Amazon during the period of colonization and settlement which reified the wilderness and the jungle as uncultivated environments in need of being tamed, optimized, and civilized through consistent projects of land transformation and economic development. Furthermore, I argue that myths about the wilderness and the jungle founded a particular mode of knowing, interacting and existing in and against the environment based on the antagonism between humans and non-human nature which was imposed as universal and continues to shape current material practices in both countries. Despite the differences between the Canadian wilderness and the Brazilian jungle, similar patterns and problems are visible in the literatures of both countries because of their colonial histories and economic models based on the capitalist development of primary resources. Thus, by analyzing a variety of Canadian and Brazilian texts, my dissertation draws attention to the relations of power within which "the forest" was constructed in the Canadian and Brazilian national imaginaries, and which, in turn, were naturalized by particular representations of the wilderness and the jungle. In so doing, my project shows the centrality of Western-centric ideals of progress, culture, nature, and modernity in both countries, and how these concepts continue to inform current institutional policies and environmental debates about forestry management, deforestation, and conservation. I argue that by questioning utilitarian models of land management, writers like Brian Fawcett, Daphne Marlatt and Jeannette Armstrong in Canada as well as Márcio Souza, Regina Melo, and co-writers Bruce Albert and Davi Kopenawa in Brazil call for a critical reinterpretation of master narratives while also inviting alternative frameworks of knowledge that run against dominant economic, environmental, and ontological models. The Canadian wilderness and the Brazilian Amazon occupy a central role in the national literatures and cultural myths of these countries. Nevertheless, the idea of the wilderness and the jungle they reify is mostly symbolic and, as such, tends to obscure the material realities of these landscapes. In turn, the texts I analyze in this dissertation unveil a connection between the imaginary and actual forestry practices enacted by companies and governments to call for epistemic, ontological, and material changes on the ground. Put another way, these narratives mediate between real world issues and aesthetic form, and try to offer a discursive structure for acting upon current environmental, cultural, and economic crises. In their critique of the sustained exploitation of humans and non-humans in postcolonial nations like Canada and Brazil, the writers I examine in my project offer the seeds a theoretical (un)thinking that brings epistemology, ontology, nature, and politics to the forefront of discussions about the environment.

Canopy structure has long been thought to influence the productivity and ecological dynamics of tropical forests by altering the availability of light to leaves. Theories and methods that can connect detailed quantitative observations of canopy structure with forest dynamics, however, have been lacking. There is urgent need to resolve this uncertainty because human-caused climate change may alter canopy structure and function in the Amazon. This work addresses this problem by, first, developing methods based on LiDAR remote sensing of fine-scale structural variation to predict the spatial structure of leaf area and light in forest canopies of the central Amazon (Appendices B&C). I show that LiDAR-based leaf area and light estimates can be used to predict the productivity of tree size groups and one-hectare forest plots--as well as differences between 2 sites separated by 500km (App. B). Sites also differed in canopy structure and the distribution of tree frequencies over size (size or diameter distribution). A model based on tree architecture, however, was able to connect observed differences in canopy architecture with size distributions to predict plot and site differences (App. D). This model showed that tree architecture is plastic in different light environments. While plasticity may increase light absorption, the smallest size groups appeared light limited. Absorption over size groups in one site, but not the other, agreed with the hypothesis of energetic equivalence across size structure. Ultimately, the performance of individual trees of different sizes in different canopy environments links forest demography with canopy structure and ecosystem function--I present a study aimed at improving tests of individual level theories for the role of light dependence in tree growth (App. A). Together, this work quantitatively connects canopy structure with forest carbon dynamics and demographic structure and further develops LiDAR as premier tool for studying forest ecological dynamics. Assessing variation in biomass growth and demographic structure over tropical landscapes with remote sensing will improve understanding of ecosystem function and the role of the Amazon in global Carbon dynamics.

O entendimento dos processos hídricos do solo, tais como infiltração, drenagem, e disponibilidade de água para as plantas, necessita do conhecimento da relação entre o conteúdo de água no solo e o potencial matricial, representado pela curva de retenção de água no solo (CRA). No entanto, a determinação da CRA demanda tempo e possui um custo relativo alto. Uma alternativa é sua determinação através de modelos que estimam a CRA a partir de alguns atributos de fácil determinação, chamados funções de pedotransferência (FPT). A finalidade desse trabalho foi quantificar os efeitos da mudança do uso do solo sobre os atributos físicos e hídricos no Sudeste do Estado do Pará. Utilizou-se o banco de dados do Projeto Serviços ecossistêmicos e sustentabilidade das paisagens agrosilvipastoris da Amazônia Oriental, para obter dados de textura (areia, silte e argila), densidade do solo (Ds), carbono orgânico (CO), pH, capacidade de troca de cátions (CTC) e, as vezes, as CRA. Primeiramente, foram avaliadas 16 FPT existentes na literatura; 8 FPT paramétricas, que estimam os parâmetros empíricos do modelo de van Genuchten e 8 FPT pontuais, que estimam a umidade em potenciais específicos de água no solo. Posteriormente, buscando maior capacidade preditiva das FPT, através da técnica de regressão múltipla, desenvolveu-se uma FPT utilizando os atributos do solo mensurados no projeto. As melhores FPT foram utilizadas para estimar os parâmetros do modelo de van Genuchten nos sítios onde não havia CRA medida. Através desta extrapolação, avaliou-se o efeito da mudança de uso do solo sobre a distribuição dos tamanhos de poros, utilizando-se análise de componentes principais (ACP). Dentre as FPT testadas, as que apresentaram melhor resultado foram as FPT propostas por Tomasella et al. (2000), no entanto, a avaliação de desempenho realizada mostrou resultados não satisfatórios. Por outro lado, os resultados apresentados pela FPT desenvolvida neste trabalho alcançaram boa capacidade preditiva dos parâmetros empíricos do modelo de van Genuchten (1980). A ACP possibilitou identificar uma grande variabilidade entre os atributos medidos e estimados dos solos. Devido a esta variabilidade, não foram detectadas diferenças marcantes nos atributos dos solos em função do uso. Para isso, faz-se necessário estudos complementares, aumentando a escala e/ou classes de solo. / The understanding of soil water attributes, such as infiltration, drainage, solute movement and water availability for plants, needs the knowledge of the relationship between water content and soil matric potential, represented by the soil water retention curve (SWRC). However, the determination of the SWRC demands considerable time and has a relatively high cost. An alternative is to model its determination using pedotransfer functions (PTF) that calculate the SWRC parameters using easily obtainable soil attributes. The aim of this study was to use PTF to quantify the effects of changing land use on soil hydro-physical attributes at three locations in southern Pará. The database obtained in the project \"Ecosystem services and sustainable agroforestry landscapes in Eastern Amazonia\" was used in order to obtain soil texture data (sand, silt and clay), bulk density (Bd), organic carbon (OC), pH, cation exchange capacity (CEC) and the SWRC. First, 16 PTF found in the literature were evaluated (8 estimating the empirical parameters of the van Genuchten (1980) model and 8 to estimate soil moisture at specific matric potentials). Later, aiming at a greater predictive ability, a PTF was developed using the technique of multiple regression and the soil attributes determined in the project. The best PTF were used to estimate the model parameters of van Genuchten (1980) at the locations where there was no SWRC data. These results were used to determine the changes in pore distribution due to land use using principal component analysis (PCA). These changes were also associated with changes in content of OC and Bd using multivariate analysis. Of the FPT found in the literature the one that showed the best performance was the FPT developed by Tomasella et al. (2000), however, the evaluation performed showed poor results when the data was extrapolated to the locations where no SWRC were determined. The results presented by the FPT developed in this work showed a better efficiency in determining the SWRC in the locations that did not have this information. The PCA analysis performed on this data identified a large variability among the measured and estimated soil attributes. Because of this variability, there were no marked differences in soil attributes depending on land use. For this, more detailed studies are necessary at a increasing scale and/or at the soil class level.