Grassland Management Affects Delivery of Regulating and Supporting Ecosystem Services

Ecosystem services (ES) are the direct and indirect contributions of ecosystems to human well-being. Grassland ecosystems cover >40% of Earth's ice-free terrestrial surface, and grassland management affects the ES provided. Our objective was to synthesize the existing literature assessing management effects on regulating and supporting ES provided by grasslands, explore the related mechanisms, and determine which practices favor ES delivery. Current literature supports the following conclusions. Increasing management intensity of grasslands through planting more productive species or increasing fertilizer inputs generally increases soil organic C (SOC) accumulation. Increasing the number of plant species or functional groups, especially when legumes are added, often increases SOC accumulation. Grazed grasslands generally accumulate SOC more rapidly than undefoliated grasslands. Low or moderate stocking rates favor SOC accumulation relative to high stocking rates, especially in lower-rainfall environments. Short-term SOC accumulation rates observed after conversion of cropland to perennial grassland do not continue indefinitely. More digestible forages defoliated at optimal maturity may decrease CH4 emitted per unit of feed consumed or per unit of animal product. Substituting legumes for N fertilizer and reducing livestock N excretion through diet manipulation reduce N2O emissions. Managing grazing to increase uniformity of excreta deposition increases efficiency of nutrient cycling. Species-rich grasslands with flower-rich legumes and forbs increase foraging opportunities for pollinators. Finally, to optimize delivery of grassland ES, management practices that sustain ecosystem function likely need to replace those that maximize short-term resource utilization or economic return. To encourage adoption, such practices may need to be incentivized.