ESPÉCIES VEGETAIS POTENCIAIS PARA RECUPERAÇÃO DE ÁREAS SOB A INFLUÊNCIA DA MINERAÇÃO DE BAUXITA EM CAMPOS DE ALTITUDE NA REGIÃO DE POÇOS DE CALDAS - MG

The objective of this work was to perform a survey of the main species derived from the propagules present on the topsoil over bauxite mines in “Altitude Fields in Atlantic Forest”, as a form to suggest potential species for recovering degraded areas. Samples were taken from the first five centimeters of substrate containing the area propagative material. The samples were housed in a nursery where we counted the plant emergences every 24 hours, identifying the individuals at the end. The abundance and diversity indexes were calculated. In this study, three of the higher occurrence species were common in both periods (dry and rainy): Ageratum fastigiatum, Echinolaena inflexa and Borreria latifolia. The value found for the Shannon Index (H’) for the species derived from propagules on the topsoil in vegetation in the altitude fields in Atlantic Forest during the dry period were of 2.79 nats.ind-1 and during the rainy period was of 2.23 nats.ind-1. Pielou’s equability observed for the dry period was of 0.72 and for the rainy period was of 0.63. The similarity between both periods was of 0.36. Comparing the response variable number of individuals between both periods, we identified a statistical difference with a larger mean for the dry period. According to the conditions this work was performed in, it is possible to ascertain that there are species with potential to recover mined areas in vegetation in altitude fields. Therefore, we suggest that ecology complementary studies are performed on these species and seed technology as a way to fundament the application of this knowledge in mined area recovery practices.O objetivo deste trabalho foi realizar um levantamento das principais espécies provenientes de propágulos na camada superficial do solo sobre minas de bauxita, em “Campos de Altitude de Mata Atlântica”, como forma de sugerir espécies potenciais para recuperação de áreas degradadas. Foram realizadas amostragens dos cinco primeiros centímetros de substratos contendo o material propagativo da área. As amostras foram acompanhadas em viveiro e realizou-se a contagem da emergência de plantas a cada 24 horas, sendo identificados os indivíduos no final do experimento. Foram calculados os índices de abundância e diversidade. Neste estudo, três das espécies de maior ocorrência foram comuns nos dois períodos (seco e chuvoso): Ageratum fastigiatum, Echinolaena inflexa e Borreria latifolia. O valor do Índice de Shannon (H’) encontrado para as espécies provenientes da camada superficial do solo em vegetação de “Campos de Altitude de Mata Atlântica” no período seco correspondeu a 2,79 nats.ind-1 e 2,23 nats.ind-1 no período chuvoso. Já a equabilidade de Pielou (J’) observada para o período seco foi igual a 0,72 e 0,63 para o período chuvoso. A similaridade entre os dois períodos foi de 0,36. Comparando a variável resposta, número de indivíduos entre os dois períodos, identificou-se diferença estatística com maior média para o período seco. De acordo com as condições que este trabalho foi realizado, é possível afirmar que existem espécies com potencial para recuperação de áreas mineradas em vegetação de Campos de Altitude. Portanto, sugere-se que sejam realizados estudos complementares de ecologia dessas espécies e de tecnologia de sementes como forma de fundamentar a aplicação desses conhecimentos em práticas de recuperação de áreas mineradas

PLANT SPECIES POTENTIALS OF RECOVERY AREAS WITH INTERFERENCE OF BAUXITE MINING IN ALTITUDE FIELDS IN PO\uc7OS DE CALDAS REGION, MG STATE

O objetivo deste trabalho foi realizar um levantamento das principais esp\ue9cies provenientes de prop\ue1gulos na camada superficial do solo sobre minas de bauxita, em \u201cCampos de Altitude de Mata Atl\ue2ntica\u201d, como forma de sugerir esp\ue9cies potenciais para recupera\ue7\ue3o de \ue1reas degradadas. Foram realizadas amostragens dos cinco primeiros cent\uedmetros de substratos contendo o material propagativo da \ue1rea. As amostras foram acompanhadas em viveiro e realizou-se a contagem da emerg\ueancia de plantas a cada 24 horas, sendo identificados os indiv\uedduos no final do experimento. Foram calculados os \uedndices de abund\ue2ncia e diversidade. Neste estudo, tr\ueas das esp\ue9cies de maior ocorr\ueancia foram comuns nos dois per\uedodos (seco e chuvoso): Ageratum fastigiatum , Echinolaena inflexa e Borreria latifolia . O valor do \ucdndice de Shannon (H\u2019) encontrado para as esp\ue9cies provenientes da camada superficial do solo em vegeta\ue7\ue3o de \u201cCampos de Altitude de Mata Atl\ue2ntica\u201d no per\uedodo seco correspondeu a 2,79 nats.ind-1 e 2,23 nats.ind-1 no per\uedodo chuvoso. J\ue1 a equabilidade de Pielou (J\u2019) observada para o per\uedodo seco foi igual a 0,72 e 0,63 para o per\uedodo chuvoso. A similaridade entre os dois per\uedodos foi de 0,36. Comparando a vari\ue1vel resposta, n\ufamero de indiv\uedduos entre os dois per\uedodos, identificou-se diferen\ue7a estat\uedstica com maior m\ue9dia para o per\uedodo seco. De acordo com as condi\ue7\uf5es que este trabalho foi realizado, \ue9 poss\uedvel afirmar que existem esp\ue9cies com potencial para recupera\ue7\ue3o de \ue1reas mineradas em vegeta\ue7\ue3o de Campos de Altitude. Portanto, sugere-se que sejam realizados estudos complementares de ecologia dessas esp\ue9cies e de tecnologia de sementes como forma de fundamentar a aplica\ue7\ue3o desses conhecimentos em pr\ue1ticas de recupera\ue7\ue3o de \ue1reas mineradas.The objective of this work was to perform a survey of the main species derived from the propagules present on the topsoil over bauxite mines in \u201cAltitude Fields in Atlantic Forest\u201d, as a form to suggest potential species for recovering degraded areas. Samples were taken from the first five centimeters of substrate containing the area propagative material. The samples were housed in a nursery where we counted the plant emergences every 24 hours, identifying the individuals at the end. The abundance and diversity indexes were calculated. In this study, three of the higher occurrence species were common in both periods (dry and rainy): Ageratum fastigiatum , Echinolaena inflexa and Borreria latifolia . The value found for the Shannon Index (H\u2019) for the species derived from propagules on the topsoil in vegetation in the altitude fields in Atlantic Forest during the dry period were of 2.79 nats.ind-1 and during the rainy period was of 2.23 nats. ind-1. Pielou\u2019s equability observed for the dry period was of 0.72 and for the rainy period was of 0.63. The similarity between both periods was of 0.36. Comparing the response variable number of individuals between both periods, we identified a statistical difference with a larger mean for the dry period. According to the conditions this work was performed in, it is possible to ascertain that there are species with potential to recover mined areas in vegetation in altitude fields. Therefore, we suggest that ecology complementary studies are performed on these species and seed technology as a way to fundament the application of this knowledge in mined area recovery practices

EFFECT OF TOPSOIL STOCKPILING ON THE VIABILITY OF SEED BANK IN FIELD PHYTOPHYSIOGNOMIES CAMPOS DE ALTITUDE

The viability of propagules during topsoil stockpiling is a limiting factor in ecological restoration projects and little is known about the species distributed in the campos de altitude. This work was carried out to investigate the viability of propagules present in the topsoil under campos de altitude vegetation, stockpiled for up to 12 months after the stripping of areas to be mined. In the south of Minas Gerais, Brazil, between November 2011 and November 2012, four collections of the seed bank were carried out, considering three depths (0 to 10, 90 to 100, and 190 to 200 cm) of the plot of stockpiled topsoil. Using the multivariate analysis, it was verified that the depth factor does not statistically affect the abundance of emerged individuals, while the factor time of stockpiling negatively affects the viability of the seeds. Some species were affected by the stockpiling conditions, only emerging in some collections, while others (Achyrocline satureioides, Ageratum fastigiatum, Baccharis dracunculifolia, Borreria capitata, Echinolaena inflexa and Melinis minutiflora) had individuals emerged in all collection periods. This study points out the need for the return of the topsoil until the fourth month of stocking, under the risk of monodominance, with a prevalence of species more adapted to predominant conditions of campos de altitude

Soil physical properties of high mountain fields under bauxite mining

Mining contributes to the life quality of contemporary society, but can generate significant impacts, these being mitigated due to environmental controls adopted. This study aimed to characterize soil physical properties in high-altitude areas affected by bauxite mining, and to edaphic factors responses to restoration techniques used to recover mined areas in Poços de Caldas plateau, MG, Brazil. The experiment used 3 randomized block design involving within 2 treatments (before mining intervention and after environmental recovery), and 4 replicates (N=24). In each treatment, soil samples with deformed structures were determined: granulometry, water-dispersible clay content, flocculation index, particle density, stoniness level, water aggregate stability, and organic matter contend. Soil samples with preserved structures were used to determine soil density and the total volume of pores, macropores, and micropores. Homogenization of stoniness between soil layers as a result of soil mobilization was observed after the mined area recovery. Stoniness decreased in 0.10-0.20 m layer after recovery, but was similar in the 0-0.10 m layer in before and after samples. The recovery techniques restored organic matter levels to pre-mining levels. However, changes in soil, including an increase in soil flocculation degree and a decrease in water-dispersible clays, were still apparent post-recovery. Furthermore, mining operations caused structural changes to the superficial layer of soil, as demonstrated by an increase in soil density and a decrease in total porosity and macroporosity. Decreases in the water stability of aggregates were observed after mining operations

DISTRIBUIÇÃO ESPACIAL DE ESPÉCIES VEGETAIS NO TOPSOIL: IMPLICAÇÕES NA RECUPERAÇÃO DE ÁREAS MINERADAS

A distribuição espacial das espécies vegetais no topsoil antes da mineração é ferramenta importante e pode fundamentar atividades de recuperação de áreas mineradas. Neste trabalho foi realizada uma análise da distribuição espacial de quatro espécies com abordagem sobre a dinâmica da regeneração em ambientes campestres. Amostras da camada superficial do solo (cinco cm) foram coletadas em agosto de 2011 e março de 2012 em áreas de campos de altitude na região do Planalto de Poços de Caldas, Minas Gerais. As amostras foram dispostas em bandejas e a germinação avaliada em casa de vegetação. Quatro espécies com maior representatividade de germinação foram selecionadas para verificar os padrões de distribuição nos períodos seco e chuvoso por meio da análise de krigagem, e destacou-se a distribuição de A. fastigiatum sugerindo sua potencial indicação para recuperação de áreas após mineração.Palavras-chave: krigagem; áreas degradadas; mapeamento vegetal. SPACE DISTRIBUTION OF SPECIES IN TOPSOIL: IMPLICATIONS TO RECOVERY OF MINING AREAS ABSTRACT: The spatial distribution of plant species in topsoil prior to mining is an important tool and may support recovery activities for mined areas. In this work an analysis of the spatial distribution of four species was carried out to verify its distribution with approach on the dynamics of regeneration in rural environments. Samples of the topsoil (5 cm) were collected in August 2011 and March 2012 in areas of altitude fields in the Planalto region of Poços de Caldas, Minas Gerais. They were arranged in trays and evaluated in a greenhouse. Four species with greater germination representativeness were selected to verify distribution patterns in dry and rainy periods through kriging analysis. Therefore, differences in the spatial distribution of the species were identified, highlighting the distribution of A. fastigiatum suggesting its potential indication for recovery of areas after mining.Keywords: kriging; degraded areas; vegetation mapping