Macrotermes termite mounds influence the spatial pattern of tree species in two African rainforest sites, in northern Congo. But were they really forests in the past?

Penel Benoit, Freycon Vincent, Marcon Eric, Rossi Vivien, Cornu Guillaume, Bénédet Fabrice, Forni Eric, Gourlet-Fleury Sylvie. 2022. Macrotermes termite mounds influence the spatial pattern of tree species in two African rainforest sites, in northern Congo. But were they really forests in the past?. Journal of Tropical Ecology, 38 (5) : 267-274.

Résumé : Termite mounds have been poorly studied in tropical rainforest in contrast to those of savannahs where they create fertility hotspots and influence the spatial pattern of vegetation. An inventory of termite mounds and of 15 tree species with a diameter at breast height ≥ 10 cm was carried out in two 800-ha blocks, in two rainforest sites located in northern Congo. We used inhomogeneous and intertype K functions to study the spatial pattern of termite mounds and of tree species around mounds, respectively. We found that mounds in Loundoungou were over-dispersed within a radius of less than 70 m, while those in Mokabi were randomly spaced. Tree species within a 20-m radius around a mound were aggregated towards the mound, e.g. Entandrophragma cylindricum, randomly distributed, or even repulsed by the mound. The specific responses also differed in the two sites. These results suggest that (i) the mounds in Loundoungou were created by savannah termite species 3,000-2,000 years BP during the Late Holocene Rainforest Crisis and (ii) the mounds in Mokabi are characteristic of forest mounds. The impact of termite mounds on the spatial pattern of tree species is thus site-dependent, and these differences might be due to species seed dispersal strategies and to soil calcium concentrations.

Mots-clés Agrovoc : Macrotermes, habitat, écosystèmes arides, écosystème forestier, distribution spatiale, savane, forêt humide, mesure (activité), topographie

Mots-clés géographiques Agrovoc : Congo

Mots-clés libres : Intertype K function, Kinhom function, Holocene, Macrotermes, Rainforest, Central Africa, Savannah, Spatial pattern

Classification Agris : L20 - Écologie animale

Champ stratégique Cirad : CTS 1 (2019-) - Biodiversité

Auteurs et affiliations

• Penel Benoit, Aix-Marseille université (FRA) - auteur correspondant
• Freycon Vincent, CIRAD-ES-UPR Forêts et sociétés (FRA)
• Marcon Eric, CIRAD-BIOS-UMR AMAP (FRA)
• Rossi Vivien, CIRAD-ES-UPR Forêts et sociétés (CMR) ORCID: 0000-0001-5458-1523
• Cornu Guillaume, CIRAD-ES-UPR Forêts et sociétés (FRA) ORCID: 0000-0002-7523-5176
• Bénédet Fabrice, CIRAD-ES-UPR Forêts et sociétés (FRA) ORCID: 0000-0001-9281-5677
• Forni Eric, CIRAD-ES-UPR Forêts et sociétés (COG)
• Gourlet-Fleury Sylvie, CIRAD-ES-UPR Forêts et sociétés (FRA) ORCID: 0000-0002-1136-4307

Source : Cirad-Agritrop (https://agritrop.cirad.fr/601539/)

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