40 Ecosystem Services Provided by Grassland Ecosystems in Southeast USA

Abstract

Abstract Ecosystem services are benefits people obtain from ecosystems. They are categorized in provisioning (e.g., animal products, fiber, timber, fruits, pods), supporting (e.g., nutrient and water cycling, soil formation, photosynthesis), regulating (e.g., climate regulation, water purification, pollination), and aesthetic/cultural (e.g., recreation/ecotourism). Grasslands are one of the major agroecosystems in Southeast USA. They provide a multitude of ecosystem services (ES) in all these categories. Grassland management impacts its ability to deliver ES. Management practices such as grazing management, fertilizer application, and diversification of vegetation cover are key aspects to consider. Proper grazing management balancing herbage mass and livestock weight (i.e., herbage allowance) results in net soil C accumulation. In fact, grasslands are one of the most important sinks of soil C. Fertilizer application might have numerous roles in the delivery of ES, some of them beneficial and some others detrimental. Benefits of applying fertilizer include increasing primary productivity and, if accompanied by proper grazing management, can result in greater livestock performance. It may also help to decay recalcitrant litter from C4 grasses and enhance nutrient cycling. Detrimental effects include the use of fossil fuels during the manufacturing process and, if applied in large amounts, might lead to nitrate leaching and denitrification. Integrating forage legumes has potential to enhance the delivery of ES by adding N via biological N fixation, enhancing nutrient cycling, improving livestock gains, and providing a better habitat for pollinating insects. Diversifying functional groups and increasing species richness is a possible way to enhance resource utilization both in space and time, reducing the need for off-farm inputs and maintaining and/or enhancing productivity. Grasslands produce far more than beef and milk. They provide ES that benefit the entire society. Mechanisms to compensate landowners must be put in place to recognize the value they are providing for the entire society.