431 Managing grazing land ecosystems for multiple ecosystem services.

摘要

Grazing lands are a significant sink for long-term carbon sequestration and play an important role in mitigating global climate change. Because of the vast area of grazing lands throughout the world, small changes in the amounts of carbon storage in this ecosystem can have significant consequences to the global carbon cycle and atmospheric CO2 levels. Carbon sequestration is strongly influenced by climate, topography, soil type, and management. Current grazing land management strategies are often aimed at increasing forage production, however, management can also promote carbon storage in the soil. Research has demonstrated that most techniques used to improve forage production promote carbon inputs to the soil and increase soil carbon sequestration. Fertilization, irrigation, grazing management, fire regimen, introduction of legumes, and use of improved grass species are management practices that can increase plant productivity while promoting soil carbon sequestration. However, management practices may also lead to unintended environmental consequences such as elevated greenhouse gas emissions, water quality problems, reduction in biodiversity, and changes in community composition. Opportunities for increasing soil carbon sequestration using land management practices are ecosystem specific and vary in intensity. Careful consideration should be given to site-specific characteristics and potential counter effects on other ecosystem services. Adoption of management practices that favor carbon inputs and minimize decomposition can also have significant positive impacts on the overall soil quality and can potentially contribute to the sustainability of grazing land ecosystems in the USA.