Soil fauna under eucalypt stands of different ages in the Savanna of Piauí

Abstract

The reforestation with eucalyptus has increased significantly in the Brazilian Savanah and it can promote changes on soil biological properties, mainly soil fauna. Thus, the aim of this study was to evaluate the composition of soil fauna in areas with Eucalyptus plantations of different ages compared with native savanna. The study was conducted in Eucalytptus plantations aged one, two, three and four years and area with native forest was taken as reference. Soil fauna was collected in the dry and rainy season to evaluate the number of individuals from different taxonomic groups, richness, uniformity and diversity. The highest number of soil fauna was found in eucalyptus plantations with one year old at both seasons. However, the richness did not differ between seasons. In areas where with eucalyptus plantations with one and two years old showed 90% of individuals represented by Coleoptera and Formicidae, which contributed for decreasing in fauna uniformity. The implantation of Eucalyptus early reduced the diversity and uniformity of soil fauna; however, there was a recovery of this biological attribute after two years of reforestation.Additional keywords: native forest; seasonality; species diversity. ResumoO plantio de eucalipto tem aumentado significativamente em áreas anteriormente ocupadas por vegetação de Cerrados, e isto pode promover mudanças nos atributos biológicos do solo, principalmente sobre a fauna edáfica. Desta forma, o objetivo do trabalho foi avaliar a composição da fauna do solo em povoamentos de eucalipto do solo com diferentes idades, em comparação com remanescentes de vegetação de Cerrados. O estudo foi realizado em quatro povoamentos de eucalipto, com 1; 2; 3 e 4 anos, e uma mata nativa de Cerrado como referência. Foram feitas avaliações do número de indivíduos de grupos taxonômicos da fauna do solo, e de características ecológicas dos grupos dessa fauna, como riqueza, riqueza média, índice de diversidade e de uniformidade. As coletas da fauna do solo foram realizadas nas estações úmida e seca. O maior número de indivíduos da fauna edáfica foi encontrado no povoamento de indivíduos com 1 ano de idade. A riqueza de espécies não diferiu entre as estações de coleta nas áreas avaliadas. Nos povoamentos com 1 e 2 anos de idade, aproximadamente 90% do total de indivíduos foram representados por Coleoptera e Formicidae, o que contribuiu para diminuir a uniformidade. Eucaliptos com menor tempo de implantação mostraram menor diversidade e uniformidade da fauna edáfica, entretanto houve recuperação destes atributos após dois anos de implantação.Palavras-chave adicionais: diversidade de espécie; mata nativa; sazonalidade.

Characterization of edaphic fauna in different monocultures in Savanna of Piauí

“…In relation to the diversity index of Shannon, eucalyptus and forest showed higher values in the two seasons probably due to the greater contributions of organic residues in the soil that favors the conditions of shelter, feeding and reproduction and creates larger ecological niches, as also verified by Cortes et al (2015). On the other hand, the soybean management system showed higher values of the Pielou index, which represents the uniformity of the distribution of the number of individuals in the different groups in each area.…”

“…In its turn, the Eucalyptus grandis Hill (ex Maiden), in which soil preparation in the region is limited to plowing and harvesting at the time of planting, provides a large amount of litter with low nutritional quality and high C / N ratio, which contributes to slow decomposition of the organic matter (Pulrolnik et al, 2009). For Cortes et al (2015) the large amount of litter generated by eucalyptus, provides certain environmental conditions favorable to the action of macro and microorganisms allowing rapid mineralization and maintaining soil nutrient availability.…”

Epigeal invertebrate fauna in monoculture and integrated systems in the cerrado biome Piauí

“…The predominance of the Formicidae and Coleoptera groups in all systems is in line with the results found by Lima et al (2019), studying epigeal fauna in different management systems in the Piauí semi-arid region. Cortez et al (2015), also found a greater predominance of the groups of Formicidae and Coleoptera, when evaluating the epigeal fauna eucalyptus crop with different ages in the cerrado of Piauí. These authors attributed the results to greater resistance and adaptation of these groups to the climatic conditions the of region.…”

“…The importance of these invertebrates has been emphasized for maintaining soil quality and the environment in the Cerrado biome (Lima et al, 2019;Santos et al, 2016;Portilho et al, 2011;Silva et al, 2011). However, there is still a lack of information on their behavior in anthropized areas and especially with eucalyptus cultivation (Souza et al, 2016;Cortez et al, 2015;Vargas et al, 2013). Moreover, more studies are needed regarding areas involving production systems with the use of eucalyptus, both in monoculture and in integrated systems, aiming at understanding the effects of different management systems and land uses on epigeal fauna.…”

Epigean fauna in no-till systems, pasture, eucalyptus and native savanna in Uruçuí, Piauí, Brazil

“…In turn, Nunes et al (2012) found that management systems adopted with different forages favored the presence of many individuals and species richness of edaphic fauna. In relation to the planted forest of eucalyptus, Cortez et al (2015) observed that the large amount of burlap generated by the crop provides favorable environmental conditions for a greater diversity of soil fauna organisms.…”