Trait divergence of woody species in relation to affinity for termite mounds in Upper Katanga (DR Congo)

Abstract

AbstractQuestionDo functional traits vary in relation to affinity for termite mounds in trees of dry tropical woodlands?LocationNorth of the Zambezian Region, Plain of Lubumbashi, Upper Katanga, DR Congo.MethodsIn four woodland sites, the occurrence of a total of 3,454 stems, on and off Macrotermes mounds has been recorded. Twenty‐one functional traits including foliar concentrations of nutrients, specific leaf area (SLA), and leaf dry matter content (LDMC) were determined in 36 species. Intraspecific variation of traits was examined in one species (Dalbergia boehmii) occurring both on and off mounds.ResultsMost species had a narrow niche, with 22 species (31%) showing a strong positive affinity for termite mounds (>90% of occurrences) (T species), and 43 species (61%) showing strong negative affinity (<10% of occurrences) (NT species). Strong divergence of traits was found between T and NT species. Affinity for termite mounds was positively correlated to SLA and foliar concentrations of B, Ca, Fe, K, Mg, and negatively correlated to LDMC and leaf thickness. Intraspecific variation in D. boehmii showed the same pattern, though with a smaller amplitude.ConclusionsStrong environmental filters are structuring the vegetation of dry tropical woodlands, with termitophilous species expressing a syndrome of faster resource capture and use, in line with the higher nutrient and water availability of termite mound soil. Broad‐niched species are either more plastic, or have evolved locally adapted populations.