Scientists can add to that effectiveness by investigating how grazing management can increase those stores. That was the message research scientist Henry Janzen brought to the Western Range Research Seminar held recently in Lethbridge. Janzen says world rangelands play an important role in the carbon cycle by keeping carbon in the soil, which means it isn't in the atmosphere as the greenhouse gas carbon dioxide. Carbon dioxide and other greenhouse gases trap radiation from the sun, increasing the earth's temperature. As international efforts such as the Koyoto agreement move to scale back production of greenhouse gas, soil as a carbon store will become more valuable.
Carbon flows through the atmosphere in a continuous cycle.
Green plants take carbon dioxide from the air, and when they die, the carbon becomes part of the soil. At the same time, Janzen says, organic matter decomposed by microbes returns carbon to the air. Any change in one part of the system affects the others, so if soil organic material is depleted by mismanagement, the carbon finds its way back into the atmosphere. Worldwide, there is about twice as much carbon in soil as in the air, and much of those carbon stores are in rangeland. Grassland soils contain more carbon per unit area than most other ecosystems worldwide.