%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Van Langenhove, L.
%A Depaepe, T.
%A Verryckt, L. T.
%A Fuchslueger, L.
%A Donald, J.
%A Leroy, Céline
%A Moorthy, S. M. K.
%A Gargallo-Garriga, A.
%A Ellwood, M. D. F.
%A Verbeeck, H.
%A Van der Straeten, D.
%A Penuelas, J.
%A Janssens, I. A.
%T Comparable canopy and soil free-living nitrogen fixation rates in a lowland tropical forest
%D 2021
%L fdi:010080461
%G ENG
%J Science of the Total Environment
%@ 0048-9697
%K Canopy soil ; Epiphytes ; Leaves ; Litter ; Bryophytes ; N-15(2) ; Terrestrial ; LIDAR
%K GUYANE FRANCAISE ; ZONE TROPICALE
%M ISI:000593987500031
%P 142202 [ ]
%R 10.1016/j.scitotenv.2020.142202
%U https://www.documentation.ird.fr/hor/fdi:010080461
%> https://www.documentation.ird.fr/intranet/publi/2021/01/010080461.pdf
%V 754
%W Horizon (IRD)
%X Biological nitrogen fixation (BNF) isa fundamental part of nitrogen cycling in tropical forests, yet little is known about the contribution made by free-living nitrogen fixers inhabiting the often-extensive forest canopy. We used the acetylene reduction assay, calibrated with N-15(2), to measure free-living BNF on forest canopy leaves, vascular epiphytes, bryophytes and canopy soil, as well as on the forest floor in leaf litter and soil. We used a combination of calculated and published component densities to upscale free-living BNF rates to the forest level. We found that bryophytes and leaves situated in the canopy in particular displayed high mass-based rates of freeliving BNF. Additionally, we calculated that nearly 2 kg of nitrogen enters the forest ecosystem through free-living BNF every year, 40% of which was fixed by the various canopy components. Our results reveal that in the studied tropical lowland forest a large part of the nitrogen input through free-living BNF stems from the canopy, but also that the total nitrogen inputs by free-living BNF are lower than previously thought and comparable to the inputs of reactive nitrogen by atmospheric deposition.
%$ 082 ; 084 ; 074