Ecosystem feedbacks and nitrogen fixation in boreal forests.
Biological feedback mechanisms regulate fundamental ecosystem processes and potentially regulate ecosystem productivity. To date, no studies have documented the down-regulation of terrestrial nitrogen (N) fixation via an ecosystem-level feedback mechanism. Herein, we demonstrate such a feedback in boreal forests. Rapid cycling of N in early secondary succession forests yielded greater throughfall N deposition, which in turn decreased N fixation by cyanobacterial associates in feather moss carpets that reside on the forest floor. The forest canopy exerts a tight control on biotic N input at a period of high productivity.
DeLuca
Thomas H
TH
Ecology and Economics Research Department, The Wilderness Society, 503 West Mendenhall, Bozeman, MT 59715, USA. tom_deluca@tws.org
Zackrisson
Olle
O
Gundale
Michael J
MJ
Nilsson
Marie-Charlotte
MC
D017753:Ecosystem; D009586:Nitrogen Fixation; D014197:Trees