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 Brazilian palm swamps (veredas) are fundamentals in the hydrological balance of watercourses in the Brazilian savanna (Cerrado). The “sponge effect” of their soils is the main factor controlling local hydrology, storing rainwater, and functioning as headwaters. The restricted knowledge of these tropical ecosystems has led to increased losses, poor preservation, and reduction in their ecosystem services. Veredas have become refuges surrounded by croplands, often drained and inappropriately managed. This study shows the impacts of anthropization on soil processes and properties of a vereda in an agricultural area. Two soil profiles were selected and characterized as preserved and anthropized, respectively upstream and downstream of the studied vereda. Morphological, physical, chemical and microbiological properties were analyzed. Principal Components Analysis (PCA) was applied to synthesize the data and provide evidence of the main properties and underlying processes that most responded to the degradation action. The arrangement of this analysis shows three main distinguish drivers: one joining the properties related to the humification of organic matter and relative accumulation of mineral matter versus accumulation of organic matter; the second with properties related to soil chemical reactivity; and the third reflecting the mineralization of organic matter. Our results suggest that the anthropic action has strongly caused the organic carbon reduction (~22 %). After 20 years, the anthropized soil presents not only a great decline in carbon stock (~14 kg m-2), but also strong impacts on several other ecologic functions, such as water holding capacity. Veredas are complex and fragile environments, and they should be fully protected to maintain their ecosystem services.

RESUMO Este estudo apresenta a análise polínica de uma turfeira localizada no Parque Nacional das Sempre-Vivas (PNSV), na Serra do Espinhaço Meridional, município de Diamantina, Estado de Minas Gerais, Brasil, para fornecer material de referência para a identificação de grãos de pólen preservados em solo de Cerrado durante o Pleistoceno e Holoceno. A análise abrangeu 16 níveis estratigráficos de um testemunho de sondagem de 162 cm de comprimento, correspondentes aos últimos 32.800 anos cal AP. A preparação química consistiu de lavagem ácida com HCl, HF, acetólise e tamisação por banho de ultrassom, com montagem do resíduo polínico em lâminas de microscopia com gelatina glicerinada. A análise foi realizada com base em observações morfológicas sob microscopia óptica e ilustrações dos grãos de pólen com base em literatura especializada. Foram identificados 116 tipos polínicos relacionados às fitofisionomias florestais ocorrentes no PNSV representadas pelas florestas semidecídua e montana, e pelas fitofisionomias do Cerrado (latu senso), áreas florestadas e formações campestres. As características morfológicas dos grãos de pólen foram bastante variáveis e podem ser utilizadas como indicadores nas reconstruções paleoambientais da sucessão da vegetação e condições paleoclimáticas do bioma Savana Tropical (Cerrado).

ABSTRACT This study presents the pollen analysis of a peatland from the Parque Nacional das Sempre-Vivas (PNSV), Serra do Espinhaço Meridional, Diamantina municipality, State of Minas Gerais, Brazil, in order to provide reference material for the identification of pollen grains preserved in Cerrado soil during Pleistocene and Holocene. The analysis involved 16 stratigraphic levels from a core of 162 cm in lenght, corresponding to the last 32.800 years cal BP. The chemical preparation consisted of acid wash with HCl, HF, acetolysis, ultrasonic bath, and mounting of the pollen residue in microscopic slides with glycerin gelatin. The analyses were carried out based on morphological observation using light microscopy and pollen grains illustration from the specialized literature. The identification of 116 pollen types was related to forest phytophysionomies, of PNSV represented by the semideciduous and mountain forest, and the Cerrado (latu senso), forest areas and grassland formations. Pollen grains morphological characteristics were greatly variable and may be used as indicators for the palaeoenvironmental reconstructions of the Tropical Savanna biome (Cerrado) succession of vegetation and paleoclimatic conditions.

O presente trabalho apresenta a morfologia polínica de treze espécies pertencentes a sete gêneros da família Fabaceae ocorrentes na área de Proteção Especial Pau-de-Fruta, Diamantina, Minas Gerais, Brasil. Os grãos de pólen das seis espécies deChamaecrista [C. cathartica (Mart.) H.S. Irwin & Barneby, C. debilis Vogel, C. flexuosa (L.) Greene, C. hedysaroides (Vogel) H.S. Irwin & Barneby, C. glandulosa (L.) Greene e C. papillata H.S. Irwin & Barneby] apresentam morfologia similar, caracterizados por 3- longos cólporos constritos na região central. As espécies compartilham características morfológicas específicas em relação ao tamanho dos grãos de pólen, tipo de endoabertura (circular, lalongada ou lolongada) e padrão de ornamentação da exina em MEV (rugulado com perfurações ou perfurado). Andira fraxinifolia Benth.,Dalbergia miscolobium Benth, Galactia martii DC, Periandra mediterranea (Vell.) Taub., Senna rugosa (G.Don) H.S. Irwin & Barneby e Zornia diphylla (L.) Pers apresentaram tipos polínicos diferenciados com tamanho de pequeno a grande; forma oblato esferoidal a prolata; aberturas em colpos ou cólporos; endoabertura circular, lalongada ou lolongada, e distintos padrões da ornamentação da exina em MEV (perfurado, microreticulado, reticulado ou rugulado com perfurações). Apenas Stryphnodendron adstringens(Mart.) Coville apresentou políades. A variação morfopolínica das espécies estudadas permitiu caracterizar a família Fabaceae como euripolínica na APE Pau-de-Fruta.

The presented paper considered the pollen morphology of thirteen species belonging to seven genera of the Fabaceae family occurring in the Pau-de-Fruta Special Protection Area (SPA), Diamantina, state of Minas Gerais, Brazil. The pollen grains of six species ofChamaecrista [C. cathartica (Mart.) H.S. Irwin & Barneby, C. debilis Vogel, C. flexuosa (L.) Greene, C. hedysaroides (Vogel) H.S. Irwin & Barneby, C. glandulosa (L.) Greene, and C. papillata H.S. Irwin & Barneby] have a similar morphology, characterized by three long colporated apertures with a central constriction. The species share specific morphological features regarding pollen size, endoaperture type (circular, lalongate or lolongate) and SEM ornamentation patterns of the exine (rugulate with perforations or perforate). Andira fraxinifoliaBenth., Dalbergia miscolobium Benth, Galactia martii DC,Periandra mediterranea (Vell.) Taub., Senna rugosa(G.Don) H.S. Irwin & Barneby and Zornia diphylla (L.) Pers showed different pollen types in small to large size; oblate spheroidal to prolate form; colpus or colporus apertures; circular, lalongate or lolongate endoapertures and distinctive SEM ornamentation patterns of the exine (perforate, microreticulate, reticulate or rugulate with perforations). Only Stryphnodendron adstringens (Mart.) Coville presents polyads. The pollen morphology variation of these species allowed the Fabaceae family to be characterized as eurypalynous in the SPA Pau-de-Fruta.