Aspectos da ecologia de Elaeis guineensis Jacq.: fenologia, entomofauna do solo e produção de serapilheira na Reserva Biológica de Saltinho - PE

Abstract

Invasive alien species threaten natural ecosystems, are efficient in the use of natural resources, have the ability to modify the characteristics of the invaded ecosystem, specifying its biodiversity. Some Conservation Units (UCs) in Brazil associate a species Elaeis guineensis as an invasive species, however, studies that proves an invasion of this species need to be carried out. Thus, the present study aimed to evaluate whether an exotic species Elaeis guineensis is causing negative effects on soil entomofauna, soil and litter in the Saltinho Biological Reserve - PE, as well as to evaluate its phenology. The phenology of the species was evaluated, the entomofauna and the contents of the macronutrients of the soil and litter were analyzed compared to two areas. For the phenological studies, 20 matrices of the species under study were selected, observing how vegetative and reproductive phenophases, monthly for a period of one year, and dendrophenogram were elaborated associating phenophases with climatic factors. To assess the possible environmental impact of the species on the environment using the soil entomofauna indicator, two areas were selected, one with the direct influence of the species E. guineensis (A1) and the other without influence (A2), as areas were at a distance approximately 50 m. Pitfall capture traps were installed, 10 in area A1 and 10 in A2, the collected organisms were screened and identified at order level. The number of orders in order of frequency was counted and the chi-square test was used to compare two areas. For the analysis of soil and litter, the same areas of the soil entomofauna methodology were used. In the soil collections, 10 were removed from each studied area, at a depth of 0-0.20 m, 15 cm away from the base of the palm trees in area A1 and randomly in A2, using a treatment to remove these people. Subsequently, the determination of macronutrients N, P, K, Ca and Mg was carried out. For the collection of litter, a square template of 0.25 x 0.25 m was used, randomly launched 10 times in each area. The collection the collection of soil and litter, the determination of macronutrients N, P, K, Ca and Mg was carried out. The results were compared using the T test at the level of 5% significance, with the aid of the statistical package R. The matrices were in constant defoliation, with homogenization in the litter of the areas with the presence of the studied species. The presence of fruits in the matrices was observed, during all studied period. The number of entomofauna visitors from the soil captured in the area with the presence of oil palm, was lower than the number sampled in the area without the influence of this species. The presence of E. guineensis is not causing significant changes in the characteristics of macronutrients in the soil and litter.