Occurrence of termites (Isoptera) on living and standing dead trees in a tropical dry forest in Mexico

PeerJ. 2018 May 16:6:e4731. doi: 10.7717/peerj.4731. eCollection 2018.

Abstract

Termites play a key role as ecosystem engineers in numerous ecological processes though their role in the dynamics of wood degradation in tropical dry forests, particularly at the level of the crown canopy, has been little studied. In this study, we analysed the occurrence of termites in the forest canopy by evaluating the density and proportion of living and standing dead trees associated with termites in deciduous and riparian habitats of the tropical dry forest in Chamela, Mexico. The results indicated that 60-98% of standing dead trees and 23-59% of living trees in Chamela were associated with termites. In particular, we found that the density of standing dead trees was higher in deciduous forests (0.057-0.066 trees/m2) than in riparian forests (0.022 and 0.027 trees/m2), even though the proportion of trees was not significantly different among habitats. Additionally, we found a higher density of trees associated with termites in trees of smaller size classes (0.01-0.09 trees/m2) than in larger class sizes (0-0.02 trees/m2). Interestingly, 72% of variation in the density of trees associated with termites is explained by the density of standing dead trees. Overall, these results indicate that standing dead tree availability might be the main factor regulating termite populations in Chamela forest and suggest that termites could play a key role in the decomposition of above-ground dead wood, mediating the incorporation of suspended and standing dead wood into the soil.

Keywords: Decay process; Ecosystem engineering; Forest canopy; Necromass; Standing dead trees; Termite occurrence; Tree density; Tropical dry forest; Wood decomposition; Xylophagous insects.

Grants and funding

This work was supported by Posgrado en Ciencias Biologicas, UNAM (as part of an Ecology field course), and by grants from CONACyT (CB-2015-253420 to Nancy Calderón-Cortés) and Universidad Nacional Autónoma de México (DGAPA-UNAM, PAPIIT # IA200918 to Nancy Calderón-Cortés). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.