ABSTRACT
ABSTRACT: The construction of the hydroelectric power plant of Ilha Solteira, in state of São Paulo, was initiated in the 1960s, when an average, 8.60 m of soil depth was removed, resulting in a degraded area. A plan for the recovery of the area started in 2005 in Selvíria /MS with the use of plant species adapted to the Cerrado biome. This study aimed to evaluate the soil macrofauna of an area under recovery by using different types of soil cover (1- bare soil (control); 2- native Cerrado vegetation; 3- specie Astronium fraxinifolium; 4- Astronium fraxinifolium + Canavalia ensiformis; 5- Astronium fraxinifolium + Raphanus sativus; 6- Astronium fraxinifolium + Brachiaria decumbens + sewage sludge). Soil macrofauna was evaluated in 2005, 2006 and 2007 using the direct collection method and manual counting. Number of species, diversity and uniformity index were determined. Principal component analysis (PCA) and cluster analysis were used for data interpretation. Results showed that treatment 6 (Astronium fraxinifolium+ Brachiaria decumbens+ sewage sludge) increased the soil macrofauna population by approximately 4 to 6 times more than the other types of cover after three years of evaluation. And the PCA and cluster analysis showed the approximation of the data between treatment 6 and Cerrado, which represents the most appropriate treatment for the recovery of the degraded soil.
RESUMO: A construção da usina hidrelétrica de Ilha Solteira, no interior de São Paulo, foi iniciada nos anos 1960, quando foi retirado, em média, 8,60 m de solo em profundidade, dando origem a uma área degradada. Com isso, iniciou-se em 2005 um plano de recuperação da área no município de Selvíria/MS com plantio de espécies vegetais adaptadas ao bioma Cerrado. Assim, este trabalho teve como objetivo avaliar a macrofauna do solo de uma área em processo de recuperação com plantio de diferentes tipos de cobertura vegetal (1- solo nu (testemunha); 2- vegetação nativa de Cerrado; 3- espécie arbórea Astronium fraxinifolium; 4- Astronium fraxinifolium + Canavalia ensiformis; 5- Astronium fraxinifolium + Raphanus sativus; 6- Astronium fraxinifolium + Brachiaria decumbens + lodo de esgoto). A macrofauna de solo foi avaliada em 2005, 2006 e 2007 utilizando o método de coleta direta e contagem manual. Foram determinados: quantidade de espécies e índices de diversidade e uniformidade. As análises de componentes principals (PCA) e de cluster foram utilizadas para interpretação de dados. Os resultados mostraram que o tratamento 6 (Astronium fraxinifolium + Brachiaria decumbens + lodo de esgoto) aumentou a população de macrofauna do solo em aproximadamente 4 a 6 vezes mais que os demais tipos de cobertura vegetal após três anos de avaliação. As análises de PCA e de cluster mostraram aproximação dos dados do tratamento 6 às condições ambientais naturais de Cerrado, indicando ser o tratamento mais adequado para a recuperação do solo degradado.
ABSTRACT
La diversidad de macro-invertebrados está relacionada con el estado de conservación del suelo, no obstante, la remoción de la cubierta vegetal natural para el establecimiento de sistemas ganaderos extensivos afecta su integridad. Una estrategia para la conservación de estos organismos es la implementación de sistemas silvopastoriles; no obstante, en el sureste de México la información aún es limitada. El propósito del presente estudio fue evaluar y comparar la riqueza y la abundancia de macro-invertebrados en cuatro agro-ecosistemas contrastantes: dos sistemas silvopastoriles conformados por Leucaena leucocephala y pastos asociados (i.e. Panicum máximum cv mombaza y Cynodon plectostachyus), un pastizal convencional de Brachiaria brizantha con árboles dispersos en baja densidad y una selva mediana subperennifolia. En cada sistema se delimitó una superficie de una hectárea y se estableció un transecto de 50 m de longitud en los que se colocaron cinco trampas de caída tipo pit-fall cada 10 m. El muestreo se realizó en febrero y mayo 2018 y en cada mes se realizaron cinco recolectas con intervalos de cinco días. Se recolectaron un total de 1 737 organismos pertenecientes a 10 órdenes de la clase Insecta y uno a la clase Gastropoda. Los sistemas con mayor abundancia de macro-invertebrados fueron el sistema de selva media subperennifolia (923 individuos) y el sistema silvopastoril de L. leucocephala con C. plectostachyus (354 individuos). Los órdenes más abundantes fueron: Hymenoptera, Coleoptera, Araneae y Orthoptera. La mayor diversidad de macro-invertebrados se presentó en los sistemas silvopastoriles de L. leucocephala con P. maximum (H'=1.58) y L. leucocephala con C. plectostachyus (H´=1.44). Los resultados encontrados muestran que los sistemas pecuarios manejados con componentes leñosos (árboles/arbustos) albergan una riqueza y abundancia importante de órdenes de macro-invertebrados en comparación con sistemas como selva mediana subperennifolia. Esta diversidad de macro-invertebrates podría contribuir a la integridad y funcionalidad de los agro-ecosistemas.
The diversity of macro-invertebrates is related to the state of disturbance of the soil, caused mainly by the land-use change for agricultural activities. A strategy for the conservation of these organisms is the implementation of diversified production systems such as silvopastoral systems. However, in the Southeast of Mexico, information is still limited. The aim of the present study was to evaluate and compare the richness, abundance and composition of macro-invertebrates in four contrasting agro-ecosystems: two silvopastoral systems made of Leucaena leucocephala and associated pastures (i.e. Panicum maximum cv mombaza and Cynodon plectostachyus), a pasture of Brachiaria brizantha with scattered trees in low density and, a medium-statured tropical dry forest. In each system, an area of one hectare was delimited and a transect of 50 m in length was established in which five pit-fall traps were placed every 10 m. The sampling was carried out in February and May of 2018 and in each month five collections were made with five-day intervals. A total of 1 737 organisms belonging to 10 orders of the class Insecta and one of the class Gastropoda were collected. The medium-statured tropical dry forest (923 individuals) and the silvopastoral systems of L. leucocephala with C. Plectostachyus (354 individuals) show the highest abundance of macro-invertebrates. The most abundant genera were: Hymenoptera, Coleoptera, Aracninae and Orthoptera. The higher macro-invertebrate diversity was found in the silvopastoral systems of L. leucocephala with P. maximum (H '= 1.58) and L. leucocephala with C. plectostachyus (H' = 1.44). The results show that livestock systems managed with woody components (trees or shrubs) are home of an important abundance and richness of macro-invertebrates, compared to tropical forests. This diversity of macro-invertebrates may contribute to the integrity and functionality of the agro-ecosystems.
ABSTRACT
Over the years, sawmilling industries have shown a high growth in the rain forest areas of Nigeria, releasing several wastes into the environment. This study aims at using earthworms (Eudrilus eugeniae, Libyodrilus violaceous and Hyperiodrilus africanus) of sawmill origin as bio-indicators of metal pollution in sawmills. Four major sawmills located in Abeokuta (7°9'11"44" N - 3°19'35" E), namely Lafenwa, Sapon, Isale-Ake and Kotopo sawmills were used for this study. The arboretum of the Federal University of Agriculture, Abeokuta was used as control site. Earthworms, plant and soil samples were collected each month for three months (March to May, 2013), randomly from different points at each of the locations. Protein analysis was conducted on the earthworms using gel electrophoresis while the activities of Superoxide dismutase (SOD), Catalase (CAT) and Glutathione peroxidase (GPx) were done spectrophotometrically. Heavy metal analysis was also conducted on soil, plant and earthworm samples using Atomic Absorption Spectrophotometer. Gel electro-phoresis results revealed the presence of nine protein bands in E. eugeniae from Sapon and Kotopo sawmills, as compared to six protein bands of E. eugeniae from the control site. Seven protein bands were observed in L. violaceous from Lafenwa and H. africanus from Isale-Ake sawmills. Levels of SOD, GPx and CAT activities were significantly higher (P < 0.05) in E. eugeniae from Sapon sawmill than those of Kotopo sawmill and the control site. This study also revealed that Pb and Cd concentrations were higher in the earthworms, plants and soil from the sawmills than those of the control site. Sapon sawmill recorded significantly higher (P < 0.05) levels of Cd and Cu in plants as well as Pb and Cd in soil samples than those of the other locations. The concentrations of Cu, Co and Ni were higher in the soil of the control site than in the sawmill soils. Stronger relationship exists in the metal concentrations between the earthworms and soils (R= 0.602) than between the plants and soil (R= 0.405). Sawmilling therefore posses potential risks on sawmill soil and soil fauna, especially earthworm species.
A través de los años, la industria de aserraderos ha mostrado un alto crecimiento en las áreas de bosque tropical de Nigeria, lanzando varios residuos al ambiente. Este estudio tiene como objetivo utilizar lombrices (Eudrilus eugeniae, Libyodrilus violaceous y Hyperiodrilus africanus) de origen aserradero como bioindicadores de contaminación por metales en los aserraderos. Se utilizaron cuatro grandes aserraderos ubicados en Abeokuta (7°9'11"44" N - 3°19'35" E), a saber: Lafenwa, Sapon, Isale-Ake y Kotopo, para este estudio. El arboreto de la Universidad Federal de Agricultura, Abeo-kuta fue utilizado como sitio de control. Las lombrices de tierra, plantas y muestras de suelo se recogieron cada mes durante tres meses (marzo a mayo 2013), al azar en diferentes puntos en cada una de las localidades. El análisis de proteínas se llevó a cabo en las lombrices de tierra utilizando electroforesis en gel, mientras que las actividades de la superóxido dismutasa (SOD), catalasa (CAT) y glutatión peroxidasa (GPx) se realizaron espectrofotométricamente. Análisis de metales pesados también se llevaron a cabo en muestras de suelo, plantas y lombrices de tierra utilizando espectrofotómetro de absorción atómica. Resultados de la electroforesis del gel reveló la presencia de nueve bandas de proteínas de E. eugeniae en los aserraderos de Sapon y Kotopo, en comparación con seis bandas de proteínas de E. eugeniae de el sitio control. Se observaron siete bandas de proteínas de L. violaceous de Lafenwa y H. africanus en los aserraderos Isale-Ake. Los niveles de SOD, GPx y actividades CAT fueron significativamente mayores (P <0.05) en E. eugeniae del aserradero Sapon que las del aserradero Kotopo y el sitio control. El estudio también reveló que las concentraciones de Pb y Cd fueron mayores en las lombrices de tierra, plantas y el suelo de los aserraderos que los del sitio control. El aserradero Sapon mostró niveles significativamente mayores (P <0.05) de Cd y Cu en las plantas, así como Pb y Cd en muestras de suelo que las de los otros lugares. Las concentraciones de Cu, Co y Ni fueron mayores en el suelo del sitio de control que en los suelos de los aserraderos. Existe relación más fuerte en las concentraciones de metales entre las lombrices de tierra y los suelos (R = 0.602) que entre las plantas y el suelo (R = 0.405). Por lo tanto, la actividad en los aserraderos posee riesgos potenciales en el suelo y su fauna, especialmente las especies de lombrices.