caa a22 4500 605516898 CHVBK 20210128100716.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s10533-014-0041-8 doi (NATIONALLICENCE)springer-10.1007/s10533-014-0041-8 Free-living nitrogen fixation responds to elevated nutrient inputs in tropical montane forest floor and canopy soils of southern Ecuador [Elektronische Daten] [Amanda Matson, Marife Corre, Juan Burneo, Edzo Veldkamp] Although often overlooked in forest research, the canopy can play an important role in forest nutrient cycling. Since the canopy is spatially isolated from the forest floor, nutrient cycling in the two areas may differ as terrestrial nutrients accumulate. We measured rates of free-living N2 fixation along an elevation gradient (1,000, 2,000 and 3,000m) of tropical montane canopy soils, compared these to rates measured in the top 5cm of forest floor soils (excluding fresh litter), and assessed the effects of elevated nutrient inputs to the forest floor. N2 fixation was measured using the acetylene reduction assay. Measurements occurred in the field, in the wet and dry seasons, using intact cores of soil. The forest floor had been fertilized biannually with moderate amounts of nitrogen (N) and phosphorus (P) for 4years; treatments included control, N, P and N+P. N2 fixation rates exhibited little variation with elevation but were higher in the dry season than the wet season. Fixation was inhibited in forest floor N plots compared to control and P plots, and stimulated in canopy P plots compared to control. At 2,000m, the canopy contributed 12% of measured canopy and forest floor N2 fixation (1.2kgNha−1year−1). Results suggest that N2 fixation is an active process in canopy soils, which is variable across seasons and sensitive to changes in terrestrial nutrient availability. Long-term terrestrial accumulation of N and/or P has the potential to significantly change the dynamics of soil N cycling in these canopies. Springer International Publishing Switzerland, 2014 N2 fixation nationallicence Arboreal soil nationallicence Canopy organic matter nationallicence Tropical Andes nationallicence Nutrient addition nationallicence Matson Amanda Buesgen Institute, Soil Science of Tropical and Subtropical Ecosystems, Georg-August University, Buesgenweg 2, 37077, Göttingen, Germany aut Corre Marife Buesgen Institute, Soil Science of Tropical and Subtropical Ecosystems, Georg-August University, Buesgenweg 2, 37077, Göttingen, Germany aut Burneo Juan Departamento de Ciencias Agropecuarias y Alimentos, Universidad Técnica Particular de Loja, Loja, Ecuador aut Veldkamp Edzo Buesgen Institute, Soil Science of Tropical and Subtropical Ecosystems, Georg-August University, Buesgenweg 2, 37077, Göttingen, Germany aut Biogeochemistry Springer International Publishing 122/2-3(2015-02-01), 281-294 0168-2563 122:2-3<281 2015 122 10533 https://doi.org/10.1007/s10533-014-0041-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10533-014-0041-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Matson Amanda Buesgen Institute, Soil Science of Tropical and Subtropical Ecosystems, Georg-August University, Buesgenweg 2, 37077, Göttingen, Germany aut NATIONALLICENCE 700 1- Corre Marife Buesgen Institute, Soil Science of Tropical and Subtropical Ecosystems, Georg-August University, Buesgenweg 2, 37077, Göttingen, Germany aut NATIONALLICENCE 700 1- Burneo Juan Departamento de Ciencias Agropecuarias y Alimentos, Universidad Técnica Particular de Loja, Loja, Ecuador aut NATIONALLICENCE 700 1- Veldkamp Edzo Buesgen Institute, Soil Science of Tropical and Subtropical Ecosystems, Georg-August University, Buesgenweg 2, 37077, Göttingen, Germany aut NATIONALLICENCE 773 0- Biogeochemistry Springer International Publishing 122/2-3(2015-02-01), 281-294 0168-2563 122:2-3<281 2015 122 10533