Impacts of cattle grazing on seed production in Rainwater Basin Wetlands

Abstract

The Rainwater Basin region of Nebraska is a critical stopover area for spring migrating waterfowl. Management concerns focus on producing sufficient wetland seed to meet the needs of these waterfowl. Cattle grazing is commonly used both alone and in combination with other management techniques to reduce invasive species such reed canarygrass that suppress seed production, but it was unknown what effect the grazing has on seed production, and how that effect might differ by vegetation type. This project examined the impact that different durations of grazing had on seed production in three sites containing both moist-soil and reed canarygrass dominated areas. We also examined the magnitude of the effect that grazing had on reducing reed canarygrass biomass with differing durations of grazing. The results suggest that cattle grazing impacts seed production differently in moist-soil and reed canarygrass dominated areas. Grazing decreases seed production in moist-soil areas, and longer grazing results in a greater decrease. In contrast, the highest seed production in reed canarygrass dominated areas was in areas grazed until July 15, and the lowest seed production was in areas grazed until September 15. The relationship between grazing and seed production in reed canarygrass areas is complex, but seed production in reed canarygrass areas was universally lower than in moist-soil vegetation at all grazing durations.