Mammals play important roles in redistributing elements across ecosystems, concentrating biogeochemical inputs across both space and time. However, research on zoogeochemical inputs is often constrained by logistical considerations, potentially limiting our knowledge of mammals' impacts on biogeochemical patterns and processes. Here, we present a bibliometric analysis that synthesizes both the spatiotemporal scope of research and range of methodological approaches used to study zoogeochemical inputs from mammals. Our assessment focuses on the major material pathways – fecal matter, urine, carcasses, and other body wastes – that are directly deposited by mammals. Our goal was to identify the ecological variables, ecosystem processes, and the spatial and temporal scales investigated by these studies, characterize geographic and taxonomic biases, and draw attention to opportunities for improved conceptual continuity. We found that while many studies effectively characterized the biogeochemical composition of mammalian inputs themselves, there is little methodological standardization across measurements that characterize the fates and functional impacts of these inputs within ecosystems. The diversity of approaches reflects the wide range of research questions in the field; however, paired with a lack of standardized measurement protocols and limited data sharing, this diversity prevents cross‐study empirical and conceptual synthesis. Notably, almost all studies were limited in duration (< 3 years) and did not follow ecosystem processes long enough to detect when (or if) the input's effects tapered off – highlighting a key opportunity for future research. Geographically, North American and European sites were relatively well represented, while deserts, boreal and tropical forests, and tropical systems were under‐represented relative to their global area. Addressing geographic biases, standardizing measurement protocols, and extending the duration of field studies to capture the full impacts of zoogeochemical inputs will enhance the ability to reconcile empirical and theoretical approaches and develop a more robust understanding of the spatiotemporal scale of mammalian control over ecosystem processes.
Ferraro et al. (Mon,) studied this question.