Effects of conservation practice, mowing, and temporal changes on vegetation structure on CRP fields in northern Missouri

To enhance and maintain wildlife benefits of Conservation Reserve Program ( CRP) lands, managers and policy makers need information on how grassland su ccession affects vegetation structure and composition as fields age. We des cribe changes in vegetation on 154 northern Missouri CRP fields sampled in 1989-1995 (field ages 1 to 9 years), including differences between cool-sea son grass and warm-season grass plantings. Within 3-4 years, CRP fields bec ame dominated by perennial grasses with substantial litter accumulation. Th ese vegetation conditions may limit the value of enrolled lands for many wi ldlife species. Once established, warm-season grass fields were taller and had more bare ground than cool-season fields. However, height and density o f vegetation on the warm-season grass fields may have precluded use by many wildlife species, even grassland birds commonly associated with tall-grass habitats. Mowing, the primary disturbance during our study, had very short -term effects on vegetation structure and led to accelerated grass successi on and litter accumulation. Thus, mowing did little to set back succession, increase diversity, and maintain or increase wildlife benefits. With wildl ife benefits having an increased role in the current CRP, program administr ators and cooperating agencies must recognize that management is necessary to maintain, and can even enhance, the wildlife benefits ascribed to specif ic CRP plantings.