RT Journal Article
T1 Nitrogen deposition effects on tissue chemistry and phosphatase activity in Cladonia foliacea (Huds.) Willd., a common terricolous lichen of semi-arid Mediterranean shrublands
A1 Ochoa-Hueso, Raúl
A1 Mejías-Sanz, V.
A1 Pérez Corona, Esther
A1 Manrique Eol, Esteban
AB In this article we evaluate the potential use of Cladonia foliacea tissue N content, C:N ratio, and phosphomonoesterase (PME) activity as biomarkers of N deposition by means of a field experiment. In order to do this, we continuously added NH4NO3 to a semi-arid shrubland at four rates: 0, 10, 20 and 50 kg N ha−1 yr−1 starting in October 2007. Tissue N content and C:N ratios, considered as N stress indicators, significantly increased and decreased, respectively, after 1.5 years. The response found suggests N saturation above 20 kg N ha−1 yr−1. After 2.5 years, extracellular PME activity increased with 20 kg N ha−1 yr−1 and this was attributed to an induced nutritional (N to P) imbalance. Above this threshold, PME significantly decreased as a consequence of the physiological stress caused by extra N. Effects on PME were dependent on the soil properties (pH and Ca and Mg availability) experienced by C. foliacea. PME response suggests a critical load of ∼26.4 kg N ha−1 yr−1 (20 kg N ha−1 yr−1 + background) for this lichen. Further tissue chemistry and PME evaluations in C. foliacea and soil surveys conducted along wide N deposition gradients will confirm the potential use of this species as a biomonitor of N pollution and the importance of soil properties on its ability to respond to atmospheric reactive N.
PB Elsevier
SN 1095-922X
YR 2013
FD 2013-01
LK https://hdl.handle.net/20.500.14352/34113
UL https://hdl.handle.net/20.500.14352/34113
LA eng
NO Ministerio de Economía y Competitividad (MINECO)
NO Comunidad de Madrid
NO Ministerio de Educación y Ciencia
NO Consejo Superior de Investigaciones Científicas (CSIC)
DS Docta Complutense
RD 4 abr 2025