Primates create seedling growth hotspots through pattern of dung deposition

Abstract

Primates play important roles in tropical forests through seed dispersal and herbivory. They comprise a large part of the biomass of forest communities and tend to have clumped patterns of defecations (i.e. at favoured food trees or sleeping sites). Therefore, they may also play important roles in accelerating ecosystem nutrient cycling. Here we conduct a controlled growth experiment to quantify the effect of the addition of primate dung on the growth of both light-demanding and shade-tolerant seedlings over 1 year in Kibale National Park, Uganda. A mixed model analysis revealed that light-demanding species were affected by the natural dung treatment and plants with small initial size had accelerated growth, whereas there was no effect on plant growth for shade-tolerant species. The long-term implications of increased dung deposition on the local tree community are unclear as shade-tolerant species may only show an effect over the long-term and light-demanding species may only be able to take advantage of the increased growth if subsequently exposed to high light conditions, such as a treefall gap.