Macrofauna edáfica em floresta secundária, pastagem e eucalipto no sudeste paraense

Abstract

Given the importance of edaphic macrofauna in the chemical transformations that sustain the organic matter cycle and the chemical fertility of the soil in tropical ecosystems and the constant changes in land use and occupation in the state of Pará, we aim to evaluate the changes in the macrofauna community structure in cronossequence of use 40 years Secondary Forest - 20 years Pasture - 10 years Eucalyptus monoculture of 10 years, in southeastern Pará. The soil macrofauna was collected using the standard method of soil monoliths from 0 to 20 cm depth. To evaluate if the changes in use of edaphic parameters determined the structure of he macrofauna, we evaluated correlations between the richness (S), Shannon-Weiner diversity index (H’), Pielou equitability (J) and density of macrofauna with soil pH (H2O), Al3+, Ca2+, Mg2+, K+, P, SOC, N, Fe, Zn and litter dry matter total content of Mn, Ca, Mg, K, P, Corg., N, Fe, Zn. 11.234 invertebrates were collected in 17.5 m2, distributed in 96 families with a mean density of 1221 (± 142) individuals per m2. The number of families associated with the Soil Use Systems (SUS) were 4.7 (63 individuals per monolith), 2,2 (74 individuals per monolith) and 3.4 (99 individuals per monolith) in Secondary Forest, Pasture and Eucalyptus Monoculture, respectively. Formicidae (70,8%) and Oligochaeta (14,8%) were the most abundant taxa. Coleoptera represented 3.92% (23% larvae) and Myriapoda 2.38% of total density. Of the families identified, 29 occurred only in the Secondary Forest, eight in the Pasture area and seven in the Eucalyptus plantation. The sequence of soil use affected the invertebrate community in the biological parameters evaluated (S, J, E) (p < 0.05). Density did not differ among Usage Systems (p> 0.05). Macrofauna density was concentrated in the litter in the Secondary Forest area (83.1%). Invertebrates tend to focus on litter in the area of Secondary Forest and Eucalyptus. The evaluated indices were highly correlated with the level of disturbance, starting gradually from the Pasture for Eucalyptus Plantation to the Secondary Forest. Apparently, the presence of tree component and consequent contribution and accumulation of litter resulted in the recovery of the number of families from Pasture to Eucalyptus after 10 years. No correlations were detected between the community structure and soil and litter chemical attributes.