Riparian health improves with managerial effort to implement livestock distribution practices

Abstract

Optimising the spatial distribution of free-ranging livestock is a significant challenge in expansive, grazed landscapes across the globe. Grazing managers use practices such as herding (i.e. droving), strategic placement of off-stream livestock drinking water and nutritional supplements, and strategic fencing in attempts to distribute livestock away from sensitive streams and riparian areas. We conducted a cross-sectional survey of 46 cattle-grazed riparian areas and associated stream reaches embedded in rugged range landscapes to examine relationships between implementation of these management practices, stocking rate, and riparian health. We determined in-stream benthic invertebrate assemblages at each site to serve as an integrative metric of riparian health. We also collected information from the grazing manager on stocking rate and implementation of livestock distribution practices at each site over the decade before this study. Off-stream livestock drinking-water sources were implemented at just two sites (4.3%), indicating that this was not a common distribution practice in these remote management units. We found no significant relationship of riparian health (i.e. invertebrate richness metrics) with stocking rate (P ≥ 0.45 in all cases), or with the simple implementation (yes/no) of off-stream nutritional supplements, fence maintenance, and livestock herding (P ≥ 0.22 in all cases). However, we did find significant positive relationships between riparian health and managerial effort (person-days spent per year for each individual practice) to implement off-stream nutritional supplements and fence maintenance (P ≤ 0.017 in all cases). Livestock herding effort had an apparent positive association with riparian health (P ≥ 0.2 in all cases). Results highlight that site-specific variation in managerial effort accounts for some of the observed variation in practice effectiveness, and that appropriate managerial investments in grazing distributional practices can improve riparian conditions.