Is the temporary grazing exclusion a good management alternative for arid peatlands?

Abstract

Highland peatlands are one of the most fragile ecosystems in the world. These ecosystems have vital nutritional importance for livestock, however previous research has indicated that intensive grazing could negatively affect these communities, requiring the application of temporary grazing exclusion to restore the health of the peatland. The objective of our study was to evaluate the effect of grazing exclusion on plant allocation strategy and carrying capacity of Oxychloe andina Phil. The plant traits of O. andina were quantified through measurements of specific leaf area (SLA) and leaf dry matter content (LDMC). We estimated the carrying capacity through livestock censuses and vegetational transects. SLA was found to be greater in grazed conditions than in ungrazed conditions (p = 0.0194) at five months after the application of treatments. Additionally, greater productivity associated with greater LDMC in March was observed under conditions of grazing exclusion (p = 0.0306). Production estimates of O. andina reached 4816 kg of dry matter (DM) distributed over an area of 9.84 ha, which was equivalent to 489 kg DM of O. andina DM ha−1. Using DM production as a proxy of the peatland and considering the average vegetation cover of 70%, the peatland produces an estimated of 1370 kg DM year−1. The temporary grazing exclusion enhanced the productivity of O. andina. However, depending on DM production in relation to grazing demand, there is a possibility of exceeding the animal load for this plant species.