Rates of free-living nitrogen fixation in some Piedmont forest types.

Abstract

Examined rates of free-living (nonsymbiotic) N-fixation in a successional sequence of forest types in the Piedmont of North Carolina. Annual N input through this process did not differ among ecosystems, averaging c0.002 kg/ha annually. The rate in a 20- to 30-yr-old stand did not increase with irrigation or additions of N, P, or Mo. Free-living N-fixation in these forests should not be expected to compensate for N losses through natural processes or management activities. -Authors