Influence of soil type on the properties of termite mound nests in Southern India Pascal Jouquet a,b, *, Nabila Guilleux a,b , Rashmi Ramesh Shanbhag c , Sankaran Subramanian b a Institute of Ecology and Environmental Sciences (UMR 242 iEES Paris), Institute of Research for Development (IRD), 32 av. H. Varagnat, 93143 Bondy, France b Indo-French Cell for Water Science (IFCWS), Indian Institute of Science, 560 012 Bangalore, Karnataka, India c Institute of Wood Science and Technology, Malleswaram, 560 003 Bangalore, Karnataka, India A R T I C L E I N F O Article history: Received 25 June 2015 Received in revised form 11 August 2015 Accepted 13 August 2015 Available online 9 September 2015 Keywords: Clay Ferralsol Luvisol Termite mound architecture A B S T R A C T Termite mounds are conspicuous features in many tropical ecosystems. Their shape and soil physicochemical properties have been suggested to result from the termites ecological need to control the temperature and humidity within their nests and protect themselves from predators. This study aimed to determine the influence of the parent soil properties on the shape and soil physical and chemical properties of termite mounds. Termite mounds built by the fungus-growing termite species Odontotermes obesus were compared in two forests with different soil properties (Ferralsol or Luvisol) in Southern India. Our findings confirm that soil properties influence the physicochemical characteristics of mound material and may affect the shape, but these impacts are mostly independent of the size of the mounds (i.e., the age of the colonies). Mound walls were more enriched in clay and impoverished in C and N in the Luvisol than the Ferralsol. However, their shape was more complex in the Ferralsol than the Luvisol, suggesting a possible link between the clay content in soil and the shape of termite mounds. The results also suggest that clay becomes enriched in O. obesus mound walls through a more passive process rather than solely by particle selection, and that termite mound shape results from the soil properties rather than the ecological needs of termites. In conclusion, although ecologists have mainly focused upon the influence of termite ecological needs on their nest properties, this study highlights the need for a better understanding about the role of the soil pedological properties and, as a consequence, how these properties drive the establishment and survival of termites in tropical ecosystems. ã 2015 Elsevier B.V. All rights reserved. 1. Introduction Fungus-growing termites (Termitidae, Macrotermitinae) con- struct belowground chambers or aboveground mounds to protect their colonies and their exo-symbiotic fungi. Depending on the challenge of their immediate environment, termites are assumed to modify the properties of their nests in two ways: first, by selecting and modifying the soil material they use and/or by modifying the shape of their mounds. For construction, fungus-growers transport clay-enriched soil from deep soil horizons to the soil surface (e.g., Jouquet et al., 2004; Abe et al., 2009, 2012; Edosomwan et al., 2012; Mujinya et al., 2013). This enrichment in clay particles improves the resistance of termite mounds to predators and rain and it is usually more significant in long-lasting structures than in short-lived soil constructions (Jouquet et al., 2002, 2005, 2007, 2015a). Termites also influence soil chemical properties, such as soil C and N contents within their nest materials. However, the influence of termites on the C and N content is highly variable. For example, the soil organic matter (SOM) content in Macroterminae-built structures was reported to be similar (Eschenbrenner, 1986), higher (Black and Okwakol, 1997; Jouquet et al., 2003), or lower (Arshad et al., 1988; Garnier-Sillam and Harry,1995; Contour-Ansel et al., 2000; Sall et al., 2002; Jouquet et al., 2005; Jouquet et al., 2015b) than the surrounding putative control soil. This large variability could be due to impacts specific to each termite species (the “behavior” force, sensu Harris, 1956) and the interaction between termite behavior and their environment (the “material” and “climate” forces). Although unstudied, it is also likely that the influence of termites on soil properties and their needs to control their environment vary according to the age of the termite colonies. Soil collection from deep layers requires more investment * Corresponding author. E-mail address: pascal.jouquet@ird.fr (P. Jouquet). http://dx.doi.org/10.1016/j.apsoil.2015.08.010 0929-1393/ ã 2015 Elsevier B.V. All rights reserved. Applied Soil Ecology 96 (2015) 282–287 Contents lists available at ScienceDirect Applied Soil Ecology journal homepage: www.else vie r.com/locate /apsoil