Theme 1: Grassland Ecology
Description
Herbivores are important for ecosystem biogeochemistry, including soil carbon pools. Non-trophic interactions between herbivores and soil processes have recently gained attention, but remain underexplored. They include both direct and indirect effects of herbivore behaviour and physical soil disturbance by herbivores (e.g., trampling) causing compaction, and therefore probably influence historical contingency; however, little empirical data on the persistent impact or legacy effect of trampling and subsequent drivers of shifts are available. To address the knowledge gaps described above, we investigated whether the soil organic C (SOC) is driven by the legacy effect of sheep trampling intensity (0, 40, 80 and 120 footsteps m-2) in a typical steppe on the Loess Plateau. Cessation of trampling for two years, typical of historical trampling intensity, had positive effects on plant Shannon, Simpson, Pielou index, belowground biomass (BGB), soil available N (SAN), soil bulk density (SBD), community-weighted mean trait values of phosphorus (CWM_P) and SOC, but had negative effects on AGB, litter biomass (LB), CWM_C and soil moisture (SM). The effect of trampling increased with increased trampling intensity. LB, BGB, CWM_C, CWM_P, SBD, SAN and SM were the main drivers of trampling-mediated SOC. From the results of this study, trampling at 40 footsteps m−2 caused by sheep managed at a stocking rate of 2.7 sheep ha−1. This appears to be compatible with rangeland adaptive management. Ecosystem function can be maintained with high stocking rates by providing adequate deferment to re-establish sufficient cover and allow natural processes to restore soil processes.
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Legacy Effects of Herbivory Trampling on Soil Organic Carbon via Soil Properties, Plant Biomass and Functional Traits
Herbivores are important for ecosystem biogeochemistry, including soil carbon pools. Non-trophic interactions between herbivores and soil processes have recently gained attention, but remain underexplored. They include both direct and indirect effects of herbivore behaviour and physical soil disturbance by herbivores (e.g., trampling) causing compaction, and therefore probably influence historical contingency; however, little empirical data on the persistent impact or legacy effect of trampling and subsequent drivers of shifts are available. To address the knowledge gaps described above, we investigated whether the soil organic C (SOC) is driven by the legacy effect of sheep trampling intensity (0, 40, 80 and 120 footsteps m-2) in a typical steppe on the Loess Plateau. Cessation of trampling for two years, typical of historical trampling intensity, had positive effects on plant Shannon, Simpson, Pielou index, belowground biomass (BGB), soil available N (SAN), soil bulk density (SBD), community-weighted mean trait values of phosphorus (CWM_P) and SOC, but had negative effects on AGB, litter biomass (LB), CWM_C and soil moisture (SM). The effect of trampling increased with increased trampling intensity. LB, BGB, CWM_C, CWM_P, SBD, SAN and SM were the main drivers of trampling-mediated SOC. From the results of this study, trampling at 40 footsteps m−2 caused by sheep managed at a stocking rate of 2.7 sheep ha−1. This appears to be compatible with rangeland adaptive management. Ecosystem function can be maintained with high stocking rates by providing adequate deferment to re-establish sufficient cover and allow natural processes to restore soil processes.
