ABSTRACT In the Cerrado, the palm swamps ( veredas ) are characterized by being humid and stable environments that lead to the formation of Histosols ( Organossolos ). and soils with surface horizons of organic constitution, which are fragile and sensitive to anthropic action. This study aimed to evaluate the impact of anthropization (recurrent forest fires and livestock farming) on the chemical, physical and morphological properties of soils in two palm swamps in the Environmental Preservation Area (EPA) of Pandeiros River, Minas Gerais, namely: Água Doce, in preserved condition, and Taboa, in anthropized condition. Four soil profiles were morphologically described, two profiles in each palm swamp, with subsequent chemical and physical analyses, calculations of organic carbon stock and identification of the origin of organic matter. The results were analyzed using descriptive statistics and Pearson’s correlation coefficient. Soil morphological properties were influenced by vegetation cover, drainage and anthropization conditions. As for the physical and chemical properties, adequate values were observed in the preserved palm swamp, including lower bulk density values and higher cation contents. Anthropic actions in the anthropized palm swamp caused degradation of soils, revealed by subsidence, reduction in organic carbon content, increase in bulk density and decrease in fertility. Changes promoted in the soils of the palm swamps compromise ecosystem services, indicating that actions at either local or governmental level should be stimulated for the preservation and conservation of these environments.

ABSTRACT There is a growing demand for more detailed knowledge about soils, their functions, and connections with human activities and environmental services. In Brazil, where soil survey and mapping have been scarce since the 1990s, there is a remarkable sense of urgency. Recently, a national soil program was created (PronaSolos) to attend to the massive demand for soil information. PronaSolos is an effort to return to the systematic soil mapping of the national territory, which requires many pedologists who master the traditional knowledge of soil mapping, but above all, the modern and accurate digital soil mapping (DSM) techniques. Based on these aspects, this study aims to address the technical and educational aspects inherent in the training process of new pedologists by contextualizing different soil mapping methods using the pedagogy project approach (PPA). Specifically, the study sought to assess the following subjects: (i) evaluate the learning process of different apprentices in performing soil survey and mapping in a small training area; (ii) compare maps generated by conventional soil mapping (CSM) and DSM using two probabilistic design for validation (SRS -Simple Random Sampling and SSRS - Stratified Simple Random Sampling). The DSM techniques evaluated were: Multinomial Logistic Regression - MLR and Random Forest - RF. For the course, four apprentices were selected and trained in both CSM and DSM techniques. Finally, they were asked about the learning process in the PPA and improvement for future courses. This study showed that: a) the PPA is promising to train new pedologists since, by mixing theoretical activities and contextualized practices (a project in progress), it not only awakens great motivation and critical capacity but also develops the ability for apprentices to find solutions in a area in constant evolution; b) the quality of the maps changed significantly according to the validation sample design applied. The CSM present better quality than DSM, mainly when using SSRS. The RF presented equivalent accuracy to CSM using SRS. Irrespective to validation sample design, the MLR presented the lowest accuracy; c) The CSMs presented higher user’s accuracy while the DSMs presented higher producer’s accuracy; d) The quality of CSM generated by the apprentices was not clearly related to the previous experience and knowledge in soil science.

ABSTRACT Soil maps are important to evaluate soil functions and support decision-making process, particularly for soil properties such as pH, carbon content (C), and cation exchange capacity (CEC), but the spatial resolution and soil depth should meet the needs of users. On another hand, the efficiency of statistical models to create soil maps, with an acceptable level of accuracy, often require a large number of samples with an appropriate distribution across the area of interest. However, accessibility for sampling can be a trouble in remote areas, such as the Itatiaia National Park (INP). The hypothesis of this work is that it is possible to obtain a viable result in soil mapping of areas with limited access by using DSM tools. The general objective of this paper was to create 2- and 3-D maps of the soil properties pH, carbon content, and CEC, with the correspondent spatial uncertainty, in the INP plateau. The sampling strategy was designed using conditioned Latin Hypercube Sample (cLHS), and different methods were tested to produce the soil properties maps. For calibration of the models: linear (MLR, multiple linear regression) and nonlinear (GAM, Generalised Additive Models). The results showed differences in predictive performance for all statistical methods and covariate selection approaches. The GAM, with covariates selection based on soil formation factors, was the best method for the limited number of soil samples. The greatest uncertainty was associated with areas with the lowest accessibility and, consequently, with low sampling density and/or noises in covariates. Even though the 2- and 3-D maps of soil properties, each associated with explicit uncertainty, can contribute to the INP decision makers/managers by providing information not available before.

RESUMO Modelos digital de elevação (MDE) usados no mapeamento digital de solo (MDS) são comumente selecionados com base em medidas e indicadores (critérios de qualidade) que refletem como um determinado MDE representa a superfície da paisagem. A hipótese é que, quanto mais acurado for um DEM, mais acurada serão as predições do MDS. O objetivo deste estudo foi avaliar diferentes critérios para identificar o MDE que fornece as predições mais acuradas do MDS. Um conjunto de 10 critérios foi utilizado para avaliar a qualidade de nove MDEs construídos com diferentes fontes de dados, rotinas de processamento e três resoluções (5, 20 e 30 m). Modelos de regressão logística multinomial foram calibrados usando 157 observações de solo e atributos de terreno derivados de cada MDE. As predições de classe de solo foram validadas usando validação cruzada leave-one-out. Os resultados mostraram que, para cada resolução, os critérios de qualidade são úteis para identificar o MDE que representa mais precisamente a superfície da paisagem. No entanto, para todas as três resoluções, o MDE mais acurado não produziu as predições mais acuradas do MDS. Com os MDEs de resolução de 20 m, as predições do MDS foram cinco pp menos acuradas ao usar o MDE mais acurado. A resolução de 5 m foi o MDE mais acurado e resultou em predições com 44% de acurácia; este valor foi igual ao obtido com duas resoluções mais grossas, MDEs com menor acurácia. Assim, a identificação do melhor MDE para o MDS exige a avaliação da acurácia das predições do MDS usando alguma forma de validação externa, porque não necessariamente o MDE mais acurado produzirá as melhores predições do MDS.

ABSTRACT Digital elevation models (DEM) used in digital soil mapping (DSM) are commonly selected based on measures and indicators (quality criteria) that are thought to reflect how well a given DEM represents the terrain surface. The hypothesis is that the more accurate a DEM, the more accurate will be the DSM predictions. The objective of this study was to assess different criteria to identify the DEM that delivers the most accurate DSM predictions. A set of 10 criteria were used to evaluate the quality of nine DEMs constructed with different data sources, processing routines and three resolutions (5, 20, and 30 m). Multinomial logistic regression models were calibrated using 157 soil observations and terrain attributes derived from each DEM. Soil class predictions were validated using leave-one-out cross-validation. Results showed that, for each resolution, the quality criteria are useful to identify the DEM that more accurately represents the terrain surface. However, for all three resolutions, the most accurate DEM did not produce the most accurate DSM predictions. With the 20-m resolution DEMs, DSM predictions were five percentage points less accurate when using the more accurate DEM. The 5-m resolution was the most accurate DEM overall and resulted in DSM predictions with 44% accuracy; this value was equal to that obtained with two coarser resolution, lower accuracy DEMs. Thus, identifying the truly best DEM for DSM requires assessment of the accuracy of DSM predictions using some form of external validation, because not necessarily the most accurate DEM will produce the best DSM predictions.

Resumo O objetivo deste trabalho foi analisar características de imagem do satélite RapidEye, bem como avaliar sua qualidade, quanto à ortorretificação, e sua aplicação no mapeamento de uso do solo, em ambiente de Mar de Morros. As imagens passaram por correção atmosférica, seguida por avaliação dos seguintes aspectos: resposta espectral a diferentes alvos, na imagem sem correção e na corrigida; acurácia da imagem ortorretificada; e exatidão da classificação supervisionada. A correção atmosférica permitiu melhor avaliação da resposta espectral dos alvos. A avaliação da ortorretificação da imagem, quanto ao Padrão de Exatidão Cartográfico, enquadrou-se na classe C da escala 1:20.000. A classificação supervisionada quantificou áreas e percentagem de cada classe de uso de forma consistente. A distribuição das classes evidencia o efeito histórico do uso na degradação das terras.

Abstract The objective of this work was to analyse RapidEye satellite image characteristics, as well as to assess its orthorectification geometric accuracy and its application for land use mapping, in a rugged landscape. An atmospheric correction was applied to the images, which was followed by the assessment of the following aspects: spectral response to different targets in the uncorrected and corrected images; accuracy of the orthorectified image; and accuracy of the supervised classification. The atmospheric correction allowed a better evaluation of the spectral response of the targets. The geometrical evaluation according to the Map Accuracy Standards, classified the orthorectified image in class C at the 1:20,000 scale. The supervised classification consistently quantified the areas and the percentage of each soil use class. The distribution of classes highlights the historical effect of the use on land degradation.

The use of indolbutyric acid (IBA) as a stimulator of rooting in cuttings of Bougainvillea spectabilis Willd. can provide increased training for marketable seedlings. This study aimed to evaluate the rooting, shoot formation and survival of herbaceous, woody and semi-woody cuttings of Bougainvillea using IBA. The cuttings were collected and treated with IBA (1000 and 2000 mg/l). At 56 days the percentage of live cuttings, rooted and with shoots, number of shoots and roots per cutting and the length of the longest root and shoot most were evaluated. The lowest percentages were found in rooting cuttings without the use of IBA. Major differences were checked for woody cuttings. The use of IBA promotes rooting of Bougainvillea, with better performance for woody cuttings and the concentration of 2000 mg/l IBA

O uso de ácido indolbutírico (IBA) como estimulador do enraizamento em estacas de Bougainvillea spectabilis Willd. pode propiciar aumento de raízes para a formação de mudas comercializáveis. Objetivou-se avaliar o enraizamento, a formação de brotos e a sobrevivência de estacas herbáceas, lenhosas e semi-lenhosas de Bougainvillea com o uso de ácido indolbutírico (IBA). As estacas foram coletadas e tratadas com o IBA (1000 e 2000 mg/l). Aos 56 dias avaliaram-se a porcentagem de estacas vivas, enraizadas e com brotos; o número de brotos e de raízes por estaca e o comprimento da maior raiz e maior broto. As menores porcentagens de enraizamento foram verificadas nas estacas sem o uso de IBA. Maiores diferenças foram verificadas para as estacas lenhosas. O uso do IBA favorece o enraizamento de estacas de Bougainvillea, com melhor desempenho para as estacas lenhosas e na concentração de 2000 mg/l de IBA