Edaphic and epigeic macrofauna responses to land use change in Brazil

Author(s)

Vanolli, Beatriz S. ; Pereira, Arthur P. A. ; Franco, Andre L. C. ; Cherubin, Mauricio R.

• Document type: Journal article
• Source: EUROPEAN JOURNAL OF SOIL BIOLOGY; v. 117, p. 13-pg., 2023-06-15.

Abstract

The expansion of sugarcane (Saccharum spp.) over extensive pasture areas has been one of the primary land-use change (LUC) scenarios in central-southern Brazil. However, LUC could negatively affect soil fauna along with the multiple functions and services associated with these organisms. Numerous groups of macroinvertebrates inhabiting the soil surface (i.e., epigeic) or the soil profile (i.e., edaphic) are fundamental for litter fragmentation, soil structuring and stabilization, water infiltration, biogeochemical cycling. In this study, both the edaphic and epigeic macrofauna communities were surveyed simultaneously to assess responses induced by the expansion of sugarcane cultivation over extensive pastures and to investigate whether the magnitude of such responses to LUC differs according to the community niche (i.e., soil profile versus surface). We hypothesized that LUC to a semi-perennial crop such as sugarcane would increase the density and diversity of the edaphic macrofauna, while the epigeic community would be negatively affected by LUC due to drastic changes in surface litter. The studied areas were two sites varying in soil texture (i.e., clay versus sandy soils) each including the following land uses: i) native vegetation, ii) extensive pasture, iii) newly planted sugarcane crop (sugarcane); and iv) established sugarcane (sugarcane ratoon). To evaluate edaphic macrofauna the TSBF methodology was adopted, while pitfall traps were installed at the same sampling points to collected epigeic macrofauna. The evaluated community attributes were density, Shannon diversity index, evenness index, richness of soil macrofauna taxa, as well as the chemical and physical attributes of the soil. Linear mixed effects analysis showed that LUC affected the relative abundance of edaphic (Land use p = 0.1191 r2marginal = 0.28, r2conditional = 0.33) and epigeic (Land use p = 0.0176; r2marginal = 0.22, r2conditional = 0.32) macroinvertebrates. Both groups showed the greatest density of organisms under native vegetation. Coleoptera and earthworms were associated with pasture areas, especially in clayey soil. Response ratios of LUC effects on macrofauna showed stronger responses of the epigeic compared to edaphic macrofauna, indicating a greater sensitivity of surface-dwelling organisms and their functions to disturbances such as those caused by LUC. In general, the density and diversity of macrofauna exhibited a positive correlation with soil organic matter, microbial carbon and nitrogen, macroporosity, and total porosity, and a negative correlation with soil density (p < 0.05). Also, the conversion of pasture to sugarcane cultivation (planting) causes significant macrofauna losses, particularly, in the clay soil. The cultivation of ratoon sugarcane led to a reduction of the density, taxonomic richness, diversity, and evenness of macrofauna. Given the importance of epigeic macroinvertebrates for litter fragmentation and decomposition, these results may indicate a rapid loss of key soil functions related to decomposition and carbon and nutrient cycling following LUC. (AU)

• FAPESP's process: 18/09845-7 - Implications of expansion and management intensification on soil ecosystem services
• Grantee: Maurício Roberto Cherubin
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/16764-6 - Changes in soil biodiversity induced by the expansion of sugarcane cultivation over extensive pasture areas
• Grantee: Beatriz da Silva Vanolli
• Support Opportunities: Scholarships in Brazil - Master