Abstract

Biological nitrogen (N) fixation is the primary source of N within natural ecosystems(1), yet the origin of boreal forest N has remained elusive. The boreal forests of Eurasia and North America lack any significant, widespread symbiotic N-fixing plants(1-6). With the exception of scattered stands of alder in early primary successional forests(7), N-fixation in boreal forests is considered to be extremely limited. Nitrogen-fixation in northern European boreal forests has been estimated(2) at only 0.5 kg Nha(-1) yr(-1); however, organic N is accumulated in these ecosystems at a rate of 3 kg N ha(-1) yr(-1) (ref. 8). Our limited understanding of the origin of boreal N is unacceptable given the extent of the boreal forest region, but predictable given our imperfect knowledge of N-fixation(1,9). Herein we report on a N-fixing symbiosis between a cyanobacterium (Nostoc sp.) and the ubiquitous feather moss, Pleurozium schreberi (Bird) Mitt. that alone fixes between 1.5 and 2.0 kg N ha(-1) yr(-1) in mid- to late-successional forests of northern Scandinavia and Finland. Previous efforts have probably underestimated N-fixation potential in boreal forests.

Published in

Nature
2002, Volume: 419, number: 6910, pages: 917-920
Publisher: NATURE PUBLISHING GROUP

SLU Authors

• Zackrisson, Olle

  • Department of Forest Vegetation Ecology, Swedish University of Agricultural Sciences
    

• Nilsson Hegethorn, Marie-Charlotte

  • Department of Forest Vegetation Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science


Publication Identifiers

DOI: https://doi.org/10.1038/nature01051

Permanent link to this page (URI)

https://res.slu.se/id/publ/115289