Impact of termite activity on soil environment: A perspective from their soluble chemical components

Abstract

An investigation on varied types of termite mounds relative to the nearby soils that are not inhabited by the termites in different places of Cameroon show that the activity of the termites is increasing the contents of most major and some trace elements in the termite mounds, except for Si and sometimes Fe, Mn, Na and K. These released elements are relocated into newly formed mineral phases that are dissolved by either H 2 O or dilute HCl leachings. The Ca and Mn released by the termite activity testify for crystallization of Ca-Mg carbonates and phosphates as well as of Fe oxy-hydroxides and/or Mn hydroxides. Termite activity also induces an increase in the lanthanide contents, the mound materials being especially enriched in light lanthanides relative to the corresponding soils without termite activity. The shapes of the patterns support precipitation of Mn-Fe oxy-hydroxides and Ca carbonates-phosphates. The increased amounts of Eu and Ce linked to termite activity seem to relate to the occurrence of reducing agents that are released by the termites, modifying Eu +3 into Eu +2 and Ce +4 into Ce +3 , favoring in turn selective incorporation of Eu +2 and Ce 3+ in the new phases of the termite mounds. Another consequence of the termite activity is the precipitation of H 2 O and HCl extractable phases having low Sr/Ca ratios. Even if the K/Rb values of the termite mounds are typical for common soil-forming silicate minerals, their relocation by an inorganic process alone does not explain an abnormally high ratio in the H 2 O leachable mineral phases. It was also shown that the main source for K and Rb of the dissolved phases is not only the interlayer site of clay particles, but also nutrients immobilized in and by the termites.

Termitarium-inhabitingBacillus endophyticusTSH42 andBacillus cereusTSH77 colonizingCurcuma longaL.: isolation, characterization, and evaluation of their biocontrol and plant-growth-promoting activities

“…The termitarium is highly enriched with humic acids, which serve as terminal electron (e -) acceptors for respiration that supports microbial growth (Lovley et al 1996). Termites are common as "ecosystem engineers" that produce significant physical and chemical modifications to tropical and sub-tropical soils (Semhi et al 2008). They generally go through a sequence of actions, including fetching, and carrying of cementing mineral particles, as well as increase organic matter in the soils used for the construction of their nests, and modify the clay mineral composition of these soil materials (Lopez-Hernandez et al 2006; Roose Amsaleg et al 2004).…”

Termites Increase Soil Productivity in Semi-Arid and Arid Tropics

“…Termite activity increases mound content of most major, and some trace elements needed for crop production (Table 2) (Semhi et al, 2008). Ca and Mg are released by termite activity and dissolved by water or HCl.…”

Kinetics, thermodynamics and competitive adsorption of lead and zinc ions onto termite mound

“…Termites are social insects that build nests in soil or wood (Eggleton et al 2002). The mounds are features built from subsoil taken from a depth as low as 3 metres below the earth surface; thus, the composition of mound soil is closely related to the nature of adjacent subsoil (Semhi et al 2008). Recently, the use of termite mound (TM) to remove Pb(II) (Abdus-Salam and Itiola 2012) and Cr(VI) (Araujo et al 2013), and defluoridation of groundwater (Fufa et al 2013) were reported.…”