Beitrag
Resource partitioning and trophic niche differentiation in riparian predators of vernal ponds
Magliochetti, Concetta; Dézerald, Olivier; González, Angélica L.
Entomologia Generalis Volume 45 Number 5 (2025), p. 1375 - 1384
veröffentlicht: Nov 18, 2025
Online veröffentlicht: Oct 23, 2025
Manuskript akzeptiert: Jul 28, 2025
Manuskript-Revision erhalten: Jul 8, 2025
Manuskript-Revision angefordert: May 13, 2025
Manuskript erhalten: Feb 2, 2025
Open Access (Arbeit kann kostenlos heruntergeladen werden)
Abstract
Understanding the factors that drive niche size and overlap is fundamental to predicting species coexistence and community assembly. Predator foraging strategies and interspecific competition play central roles in shaping trophic niches, but many species mitigate competition through trophic or microhabitat differentiation. Environmental factors, such as habitat size and prey availability, can further influence species interactions by altering prey diversity and accessibility. In this study, we investigated isotopic niche partitioning and specialization within a riparian invertebrate carnivore guild, focusing on arachnids and odonates – two dominant predators in vernal pond ecosystems of the New Jersey Pine Barrens. Using stable isotope analysis of carbon (δ13C) and nitrogen (δ15N), we quantified the trophic niches of each group across eight ponds, assessing differences in niche size, overlap, and the role of environmental drivers. Odonates exhibited significantly larger isotopic niches than arachnids, a pattern that may reflect broader, foraging behavior or aggregation of more ecologically variable taxa. Despite these differences, the trophic niches of arachnids and odonates overlapped by approximately one-third, indicating moderate overlap consistent with partial resource partitioning. Such differentiation may reflect divergent prey use or foraging modes that facilitate coexistence despite shared habitat use. Odonate niche size was negatively correlated with pond size and the abundance of certain prey taxa, particularly Coleoptera and Hymenoptera, while arachnid niche size was unaffected by environmental factors. These results suggest that coexistence in this predator guild is maintained through niche differentiation, potentially via differences in spatial or temporal resource use. Our findings highlight the complex interplay between predator behavior and environmental context in shaping trophic interactions within riparian food webs.
Schlagworte
isotopic niche • odonates • arachnids • niche overlap • predator coexistence • habitat size • riparian ecosystems • community assembly