Soil modification by termites in a sandy-soil vegetation in the Brazilian Atlantic rain forest

Abstract

Abstract:Termites play a critical role in the regulation of soil processes, for example, water retention, nutrient cycling, and the formation and maintenance of soil structure. There is a consensus that mound-building termites modify physical and chemical soil properties in clay soils, but there is limited investigation into their influence for sandy soils in the Brazilian Atlantic rain forest. We tested the hypotheses that the termitosphere effectively improves properties of sandy soil, and that the role of termite soil particle selection is of greater importance in soils with higher sand concentration and lower nutrient status. The work was conducted in three vegetation physiognomies: woodland, savanna and grassland. In the woodland physiognomy we sampled in the border and in the interior, totalling four studied areas. We described a soil profile and collected five samples of termitaria and surface soil in each area. Also, in three 100-m2 plots allotted in each area, termite-mound density and volume were estimated, and termites were collected for taxonomic identification. Soil samples were submitted to physical and chemical analysis, and regression models were employed to analyse termite particle selection ability in different soil conditions. In most areas, the concentrations of nutrients, organic carbon and clay-size particles were significantly higher in termite mounds than in surface soils. On a weight basis, termite mounds had up to 32 times more nutrients, 12 times more organic carbon, and five times more clay than surrounding soils, however, aluminium toxicity was lower in termite mounds. Regression models demonstrated that the role of termites in soil particle selection is of greater ecological importance with decreasing soil nutrient status and increasing sand concentration. Therefore, termites greatly improve soil properties, representing truly ecosystem engineers in sandy soils, with an average soil turnover by mound-building activity reaching 10.5 m3 ha−1.

Termite Mounds Effects on Soil Properties in the Atlantic Forest Biome

“…The results of this study corroborate those of Peres Filho et al (1990) and Sarcinelli et al (2013), who found higher clay contents in mounds than in soils at different sampling distances. A higher clay content in mounds was also reported by Oliveira et al (2012), but not for the other fractions.…”

“…Subsequently, the soil around the mounds was sampled. Single samples were collected from around each nest (layers 0.00-0.05 and 0.05-0.10 m), at distances of 0.50 and 1.50 m from the mound base, the same as used in other studies (Kaschuk et al, 2006;Sarcinelli et al, 2009;Joseph et al, 2013;Sarcinelli et al, 2013). Per mound, a total of four samples were retrieved from the surrounding soil (Figure 1).…”

Ant‐termite interactions: an important but under‐explored ecological linkage

“…Termites produce enzyme‐ and microbial‐rich faeces and hence contribute to the soil microbial pool and to nutrient redistribution (Jouquet et al ., ). The nutrients in ingested matter that are not used by the termites are deposited within the mound, with these mounds consequently becoming nutrient rich relative to the surrounding area (Brauman, ; Sarcinelli et al ., ). As a result, these fertile mounds are characterised by vegetation that differs from that found in the rest of the habitat (Muvengwi et al ., ).…”

Leaf Residue Decomposition of Selected Atlantic Forest Tree Species

“…Moreover, the Collembola (microphages) also influenced the decomposition of plant residues by fragmenting them and playing an important role in soil microstructure formation, creating a favorable balance between bacteria and fungi, producing enzymes (Nunes, 2003). Termites also have a key function in soil structure formation in Latosols (Schaefer, 2001;Sarcinelli et al, 2013).…”