• Citer

The big picture: Disentangling drivers of dung nutrient stoichiometry of mammalian herbivores in African savannas

par Jaafar, Ridwan
Promoteur Olde Venterink, H
Co-Promoteur Sitters, Judith;Elizabeth, Le Roux
Publication Non publié, 2021-08-31

Mémoire

• Accès en ligne
• Détails
• Contenu
• Statistiques

Résumé :

Herbivore-driven nutrient cycling is a key ecological process in African savannas. It is wellknown that essential nutrients like nitrogen (N) and phosphorus (P) in dung vary instoichiometric ratios and this may not only shape nutrient dynamics but may haveimportant ecological implications for plant competitive interactions. Theory suggests dungstoichiometry to vary with body stoichiometry and diet composition of herbivores.However, our empirical understanding of the patterns of and mechanisms underlying dungN:P stoichiometry, especially in terrestrial vertebrate herbivores, are limited. Here, Icompiled a comprehensive dung nutrient dataset containing estimates from 44 herbivorespecies across 28 locations in 10 African countries. I used this dataset to test the effects ofbody size, diet composition and digestive physiology in predicting dung N, P and N:Ppatterns. I further investigated the influence of habitat type and rainfall seasonality on dungstoichiometry. I found that both body size and diet composition strongly predicted dung N:Pstoichiometry, with dung P and N:P quadratically related to body size, reflecting bodystoichiometric requirements in herbivores. Dung N and N:P decreased with dung δ13C,indicating that the relative proportion of C3/C4 plants in herbivore diet impacted dungstoichiometry. I found an interactive effect of season and habitat on dung N concentrations,but not on dung P. Overall, my study demonstrates a more complete understanding of dungstoichiometric patterns among mammalian herbivores of African savannas, providing anunprecedented empirical insight to advance the current theory on ecological stoichiometry.