Herding the Literature: Trends in Large Mammalian Herbivore Grazing and Foraging Ecology Research over the Past Three Decades

Large herbivores are often considered keystone species, driving the structure composition and dynamics within ecosystems, particularly for rangelands, which are often defined in terms of their productive capacity for livestock and game products. Grazing and foraging ecological research have been instrumental in developing a theoretical and empirical understanding of the role these herbivores play in natural and agricultural systems. We used a variety of text analysis techniques (e.g., topic modelling, geoparsing, taxonomic entity extraction) to assess key questions in the academic literature on grazing and foraging ecology research. These relate to understanding of the spatial and temporal trends and the main topics encapsulated within this research. We identified clear and distinguishable topics of research activity that spanned across methodological and analytical fields and subject matter. The subject matter topics related to specific areas of research (e.g., seed germination and dispersal), systems and modeling (e.g., modeling grazing systems), and management (e.g., rangeland management). Our analyses showed how the prevalence of these topics in the literature changed over time. Rangelands were the most common biome for research, with deer (Cervus and Odocoileus) as the most mentioned genera. The United States produced the most research, but China's output has grown over time. The research demonstrates that grazing and foraging ecology of ungulates (livestock and wildlife) is increasing; is highly dynamic in topic, space, and time; and that rangelands are, and have been, important in the development of research in the fields. Trends suggest that rangelands and rangeland management will continue to be important areas of research with modeling and greenhouse gas emissions growing in prevalence, particularly as China increases its contribution to the corpus.