Acclimatation of three co-occurring tree species to water stress and their role as site indicators in mixed pine-oak forests in the Sierra Madre Oriental, Mexicot

• Published in: European journal of forest research 2012-03, Vol.131 (2), p.355
• Main Authors: Himmelsbach, Wibke, Treviño-garza, Eduardo J, González-rodríguez, Humberto, González-tagle, Marco A, Gómez Meza, Marco V, Aguirre Calderón, Oscar A, Eduardo Estrada Castillón, A, Mitlöhner, Ralph
• Format: Article
• Language: English
• Subjects: Biodiversity; Climate change; Coniferous forests; Drought; Forests; Indigenous species; Leaves; Moisture content; Plant species; Soil water; Trees; Variance analysis; Water; Water availability; Water content; Water loss; Water potential; Water stress
• ISSN: 1612-4669; 1612-4677
• DOI: 10.1007/s10342-011-0507-3

Water availability and salt excess are limiting factors in Mexican mixed pine-oak forest. In order to characterise the acclimatation of native species to these stresses, leaf water (Ψ^sub w^) and osmotic potentials (Ψ^sub s^) of Juniperus flaccida, Pinus pseudostrobus and Quercus canbyi were measured under natural drought and non-drought conditions under two different aspects in the Sierra Madre Oriental. Factorial ANOVA revealed significant differences in Ψ^sub w^ and Ψ^sub s^ between two aspects, species and sampling dates. In general, all species showed high predawn and low midday values that declined progressively with increasing drought and soil-water loss. Seasonal and diurnal fluctuation of Ψ^sub w^ and Ψ^sub s^ were higher for J. flaccida and Q. canbyi than for P. pseudostrobus. Leaf Ψ^sub w^ and Ψ^sub s^ were mainly correlated with soil water content, while Ψ^sub s^ of P. pseudostrobus were hardly correlated with environmental variables. Thus, species have different strategies to withstand drought. P. pseudostrobus was identified as a species with isohydric water status regulation, while J. flaccida and Q. canbyi presented water potential patterns typical for anisohydric species. The type of water status regulation may be a critical factor for plant survival and mortality in the context of climate change. Nevertheless, for precise conclusions about the advantages and disadvantages of each type, further long-term investigations are required.[PUBLICATION ABSTRACT]