Dr. Smeins' research focuses on understanding the structure and dynamics of rangeland (grassland, wetland, savannah) ecosystems as influenced by herbivory, soil, fire and weather. Factors that control the pattern and rate of plant succession and retrogression are primary objects of study. Primary production, plant competition, woody/herbaceous plant interactions, soil seed banks, species diversity patterns and endangered species are investigated. Research is conducted in tallgrass prairies, Edwards Plateau savannahs, longleaf pine savannahs and coastal marshes. He has conducted research and development work in Kenya, Somalia, Morocco, Venezuela and Italy. Over 85 technical papers, book chapters and bulletins have been published. Current research includes life history and successional studies of Ash juniper, life history studies of Olney bulrush, impact of snow geese on coastal marsh plant communities, habitat features of Golden Cheeked Warblers, influence of summer burning on Edwards Plateau rangelands and Blackland Prairie Restoration.