Long-term nitrogen deposition linked to reduced water use efficiency in forests with low phosphorus availability
Huang, Zhiqun (Fujian Normal University. Key Laboratory for Subtropical Mountain Ecology)
Liu, Bao (Fujian Agriculture and Forestry University. College of Forestry)
Davis, Murray (Scion (Organization : N.Z.))
Sardans i Galobart, Jordi (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Peñuelas, Josep (Universitat Autònoma de Barcelona. Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia)
Billings, Sharon (University of Kansas. Department of Ecology and Evolutionary Biology)

Data:	2016
Resum:	1. The impact of long-term nitrogen (N) deposition is under-studied in phosphorus (P)-limited subtropical forests. We exploited historically collected herbarium specimens to investigate potential physiological responses of trees in three subtropical forests representing an urban-to-rural gradient, across which N deposition has probably varied over the past six decades. We measured foliar [N] and [P] and stable carbon (δ¹³C), oxygen (δ¹⁸O) and nitrogen (δ¹⁵N) isotopic compositions in tissue from herbarium specimens of plant species collected from 1947 to 2014. - 2. Foliar [N] and N : P increased, and (δ¹⁵N and [P] decreased in the two forests close to urban centers. Consistent with recent studies demonstrating that N deposition in the region is 15N-depleted, these data suggest that the increased foliar [N] and N : P, and decreased [P], may be attributable to atmospheric deposition and associated enhancement of P limitation. - 3. Estimates of intrinsic water use efficiency calculated from foliar (δ¹³C decreased by c. 30% from the 1950s to 2014, contrasting with multiple studies investigating similar parameters in N-limited forests. This effect may reflect decreased photosynthesis, as suggested by a conceptual model of foliar (δ¹³C and δ¹⁸O. - 4. Long-term N deposition may exacerbate P limitation and mitigate projected increases in carbon stocks driven by elevated CO₂ in forests on P-limited soils.
Ajuts:	European Commission 610028
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Matèria:	Herbarium specimens ; Nitrogen : phosphorus (N : P) ; P-limited soils ; δ¹³C ; δ¹⁵N
Publicat a:	The new phytologist, Vol. 210, Issue 2 (April 2016) , p. 431-442, ISSN 1469-8137

DOI: 10.1111/nph.13785

Post-print 31 p, 1.3 MB

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Documents de recerca > Documents dels grups de recerca de la UAB > Centres i grups de recerca (producció científica) > Ciències > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals) > Imbalance-P
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