'Composicao Revista de Ciencias Sociais da Universidade Federal de Mato Grosso do Sul'
Abstract
The objective of this work was to evaluate the composition and structure of leguminous species in vegetal formation of rocky fields in Serra do Espinhaço Meridional, as well as to verify the diversity of nitrogen-fixing bacteria of the nodular species. The floristic survey was carried out in a reserve area belonging to the Anglo American mining company, based in the municipality of Conceição do Mato Dentro - MG. The region is located on the eastern edge of the Serra do Espinhaço Meridional and has a Cwa climate. To carry out the floristic survey, 25 fixed plots (10×10 m) were installed for the shrub-tree compartment and 60 fixed plots (1 × 2 m) for the herb-subshrub compartment. Absolute and relative density, absolute and relative frequency were estimated for both compartments. After the previous floristic survey, 40 root nodules of the species of Calliandra fasciculata and 23 of Moldenhawera emarginata were collected. Afterwards, bacteria were isolated from the nodules from the species C. fasciculata and M. emarginata. The cultural characteristics of the isolates were evaluated and from the data, it was possible to group the isolates through a cultural dendrogram using the Jaccard coefficient, using the MVSP (Multivariate Statistical Package) software. Three leguminous species were recorded in both compartments, totaling 1192 individuals distributed among C. fasciculata (with 1080 ind.), M. emarginata (with 86 ind.) and Periandra mediterranea (with 26 ind.). However, for the species P. mediterranea, no nodulation was observed in the field. The species C. fasciculata was responsible for 92.62% of the total number of individuals. From the morphological characteristics successfully evaluated, of the 23 isolates of C. fasciculata, 6 cultural groups were obtained. This result suggests high morphophysiological diversity of nitrogen-fixing bacteria nodulating the species in question, in a quartzite rock field environment. Due to the importance of this species, its use in recovery projects is recommended, especially in environments similar to the one in this study.Este trabalho teve o objetivo de avaliar a composição e estrutura de espécies leguminosas em formação vegetal de campo rupestre na Serra do Espinhaço Meridional, assim como verificar a diversidade de bactérias fixadoras de nitrogênio das espécies nodulíferas. O levantamento florístico foi realizado em uma área de Reserva Legal da empresa Anglo American no município de Conceição do Mato Dentro, Minas Gerais. A região está inserida na Borda Leste da Serra do Espinhaço Meridional e apresenta clima Cwa. Instalou-se 25 parcelas fixas (10 × 10 m) para a comunidade arbustivo-arbóreo e 60 parcelas fixas (1 × 2 m) para a comunidade herbáceo-subarbustivo no levantamento florístico. Foram estimadas a densidade absoluta e relativa, frequência absoluta e relativa para ambas as comunidades. Após o levantamento florístico prévio, realizou-se a coleta de 40 nódulos da raiz das espécies de Calliandra fasciculata e 23 de Moldenhawera emarginata. Em seguida, realizou-se o isolamento das bactérias dos nódulos provenientes das espécies C. fasciculata e M. emarginata. Foram avaliadas as características culturais dos isolados e a partir dos dados, foi possível agrupar os isolados por meio de um dendrograma cultural com a utilização do coeficiente de Jaccard, pelo software MVSP (Multivariate Stastitical Package). Três espécies leguminosas foram registradas em ambos as comunidades, totalizando 1.192 indivíduos distribuídos dentre C. fasciculata (com 1080 ind.), M. emarginata (com 86 ind.) e Periandra mediterranea (com 26 ind.). Contudo, na espécie P. mediterranea não foi constatada nodulação em campo. A espécie C. fasciculata foi responsável por 92,62% do total de indivíduos. A partir das características morfológicas avaliadas, dos 23 isolados de C. fasciculata, obteve-se 6 grupos culturais. Este resultado sugere alta diversidade morfofisiológica de bactérias fixadoras de nitrogênio nodulando essa espécie em ambiente de campo rupestre quartzítico. Devido à importância desta espécie, recomenda-se seu uso em projetos de recuperação, especialmente em ambientes semelhantes ao deste estudo.
Palavras-chave: endemismo; Fabaceae; nitrogênio; nodulação.
Nodulating legumes with potential for use in the recovery of degraded areas in quartzite rocky fields
ABSTRACT: The objective of this work was to evaluate the composition and structure of leguminous species in the vegetal formation of rocky fields in Serra do Espinhaço Meridional, as well as to verify the diversity of nitrogen-fixing bacteria of the nodular species. The floristic survey was carried out in a reserve area based in the municipality of Conceição do Mato Dentro, Minas Gerais. The region is located on the eastern edge of the Serra do Espinhaço Meridional and has a Cwa climate. Twenty-five fixed plots (10 × 10 m) were installed for the shrub-tree compartment and 60 fixed plots (1 × 2 m) for the herb-subshrub compartment to carry out the floristic survey. Absolute and relative density, absolute and relative frequency were estimated for both compartments. After the previous floristic survey, 40 root nodules of the species of Calliandra fasciculata and 23 of Moldenhawera emarginata were collected. Afterward, bacteria were isolated from the nodules of C. fasciculata and M. emarginata. The cultural characteristics of the isolates were evaluated and from the data, it was possible to group the isolates through a cultural dendrogram using the Jaccard coefficient, using the MVSP (Multivariate Statistical Package) software. Three leguminous species were recorded in both compartments, totaling 1192 individuals distributed among C. fasciculata (with 1080 ind.), M. emarginata (with 86 ind.) and Periandra mediterranea (with 26 ind.). However, for the species P. mediterranea, no nodulation was observed in the field. The species C. fasciculata was responsible for 92.62% of the total number of individuals. From the morphological characteristics successfully evaluated, of the 23 isolates of C. fasciculata, 6 cultural groups were obtained. This result suggests high morphophysiological diversity of nitrogen-fixing bacteria nodulating this species in a quartzite rock field environment. Due to the importance of this species, its use in recovery projects is recommended, especially in environments similar to the one in this study.
Keywords: endemism; Fabaceae; nitrogen; nodulation
