Stomatal conductance of semi-natural Mediterranean grasslands: Implications for the development of ozone critical levels

• Published in: Environmental pollution (1987) 2007-04, Vol.146 (3), p.692-698
• Main Authors: Alonso, R., Bermejo, V., Sanz, J., Valls, B., Elvira, S., Gimeno, B.S.
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Biomass; Bromus - drug effects; Bromus - physiology; Critical levels; Ecosystem; Ecotoxicology, biological effects of pollution; Environmental Exposure - adverse effects; Fabaceae - drug effects; Fabaceae - physiology; Fundamental and applied biological sciences. Psychology; Grasslands; Models, Biological; Nitrogen - metabolism; Oxidants, Photochemical - analysis; Oxidants, Photochemical - toxicity; Ozone; Ozone - analysis; Ozone - toxicity; Plant Leaves - drug effects; Plant Leaves - physiology; Poaceae; Poaceae - drug effects; Poaceae - physiology; Risk Assessment - methods; Semi-natural vegetation; Spain; Species Specificity; Stomatal conductance; Terrestrial environment, soil, air; Trifolium; Trifolium - drug effects; Trifolium - physiology
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2006.06.009

Intra-genus and intra-specific variation and the influence of nitrogen enrichment on net assimilation and stomatal conductance of some annual Trifolium species of Mediterranean dehesa grasslands were assessed under experimental conditions. Also gas exchange rates were compared between some Leguminosae and Poaceae species growing in the field in a dehesa ecosystem in central Spain. The results showed that the previously reported different O 3 sensitivity of some Trifolium species growing in pots does not seem to be related to different maximum g s values. In addition, no clear differences on gas exchange rates could be attributed to Leguminosae and Poaceae families growing in the field, with intra-genus variation being more important than differences found between families. Further studies are needed to increase the database for developing a flux-based approach for setting O 3 critical levels for semi-natural Mediterranean species. The stomatal conductance model incorporated within the EMEP DO 3SE deposition module needs to be re-parameterised for Mediterranean semi-natural vegetation.