Soil macrofauna in a Cerrado/Caatinga ecotone under different crops in Southwestern Piauí State, Brazil

Abstract

The aim of this study was to characterize the soil macrofauna under different crop systems and compare them to the macrofauna under the native vegetation of a Cerrado/Caatinga ecotone in southwestern Piauí State, Brazil. The areas studied included areas under sweetsop cultivation (Annona squamosa L.), andropogon grass with three years of use, andropogon grass with six years of use, pivot-irrigated corn, Napier grass, and native vegetation. In each area, soil layers of 0-0.1, 0.1-0.2, and 0.2-0.3m, including the surface litter, were evaluated following the Tropical Soil Biology and Fertility Program (TSBF) recommendations. The soil macrofauna from the different land-use systems were identified to the family level, and the mean density of each taxon was calculated for each soil-management type and layer. The structure of the soil macrofauna was negatively altered under the different crops in comparison to the native Cerrado/Caatinga vegetation, with macrofaunal occurrence varying in the different soil layers. A correlation existed between the functional groups and the soil grain-size distribution and moisture. Napier grass cultivation favored greater soil macrofaunal abundance, with a predominance of families belonging to the orders Isoptera and Hymenoptera. Number of soil macrofaunal families under pivot-irrigated corn was more like the number observed with the native vegetation, and corn also had greater family diversity compared to the other crops studied. Therefore, pivot-irrigated corn can reduce the impact of anthropogenic land use on the diversity of soil macrofauna.

Edaphic macrofauna associated with the cultivation of maize (Zea maiz)

“…Ants are important bioindicators, since they adapt to different disturbance regimes, such as an increase in the number of invasive plants, inhibition of decomposition, and contamination levels, generally due to agrochemicals 40 . The number of families of soil macrofauna in corn crops is similar to that of native vegetation 41 , leaving open the possibility of studying it in neighboring native plots. Ants and termites are classified as "ecosystem engineers " 42 , present in low altitude soils 43 .…”

Composição, abundância e diversidade da fauna edáfica em um fragmento de Caatinga

“…As ordens Acarina, Entomobryomorpha, Poduromorpha, Coleoptera, Hymenoptera e Araneae, presentes entre os mais abundantes na Fazenda Experimental Piroás, são indicados em diversos estudos como potenciais bioindicadores por serem comumente amostrados, em maior abundância, em diferentes ambientes, e sob diferentes manejos e por responderem de forma rápida às alterações ambientais (MUDREK et al, 2014;SANTOS et al, 2017;SILVA et al, 2013;SILVA et al, 2015;SPILLER et al, 2018). Os ácaros (acarina) juntamente com as ordens da classe Entognatha são os principais organismos da mesofauna edáfica, desempenhando importantes funções no ecossistema ao atuarem como decompositores e facilitadores de grupos de micro-organismos (GRIESANG et at., 2016).…”

Macrofauna edáfica como bioindicadora da qualidade do solo em diferentes sistemas de manejo

“…The Coleoptera are good environmental indicators because there is a high diversity, occupying different trophic levels, having their specificities within their ecological niches, and changes in soil management are sensitive (Kitamura et al, 2020). Besides, colepterans are predators and regulate insect populations (Santos et al, 2017).…”

“…The Formicidae, Isoptera and Oligochaeta groups are recognized as ecosystem engineers (Lavelle et al, 1997) because they have a functional role in the decomposition of plant residues and organic matter. Formicidae and Isoptera also contribute to the porosity and infiltration of water in the soil due to their construction of galleries and nests in the soil and Oligochaeta, which was also present in all areas (Santos et al, 2017;Araújo et al, 2018). According to Brown et al (2015), these groups contribute to ecosystem support and regulation services, as they have significant roles in the biome's ecology.…”