Interspecific competition influences the response of oak transpiration to increasing drought stress in a mixed Mediterranean forest

FOREST ECOLOGY AND MANAGEMENT

卷:318

Article

Grossiord, Charlotte¹  Gessler, Arthur^2,3  Granier, Andre¹  Pollastrini, Martina⁴  Bussotti, Filippo⁴  Bonal, Damien¹ 

[1] INRA, UMR Ecol & Ecophysiol Forestieres 1137, F-54280 Champenoux, France

[2] Leibniz Ctr Agr Landscape Res ZALF, Inst Landscape Biogeochem, D-15374 Muncheberg, Germany

[3] Berlin Brandenburg Inst Adv Biodivers Res BBIB, D-14195 Berlin, Germany

[4] Univ Florence, Dept Agrifood & Environm Sci, Sect Soil & Plant Sci, I-50144 Florence, Italy

关键词: Drought;    Sap flux;    Quercus;    Species interactions;    Water use efficiency;   

DOI  :  10.1016/j.foreco.2014.01.004

来源: Elsevier

【 摘 要 】

Increasingly severe droughts are expected to negatively impact forest functioning in the future, especially in the Mediterranean region. Favoring mixed species stands has been advocated as a compromise between wood production and biodiversity conservation, but whether such management practices would allow forest ecosystems to acclimate to future climate conditions remains to be addressed. We tested whether the transpiration of Quercus cerris (Qc) and Quercus petraea (Qp) during droughts differ when they grow in pure or mixed forests. We measured sap flux density (F-D) and leaf carbon isotope composition (delta C-13), as a proxy for intrinsic water use efficiency (WUEint), in pure and mixed Qc and/or Qp forest plots in Italy during the summer 2012. Qc and Op showed a drop in FD of 41% and 52% respectively during the summer drought independently of the mixtures, but with different seasonal trends. Qp transpiration response to soil drought did not differ between pure and mixed plots. In contrast, Qc transpiration was reduced by 56% in mixed plots at the maximum of the drought and only by 31% in the pure plot. Furthermore, we observed higher WUEint for Qc in the mixed plot and no change for Qp, supporting the higher water stress intensity in the mixed plot for Qc. Our study illustrated the negative impact of Qp on Qc when these species compete for water resources. We suggest that managing for mixed stands in the Mediterranean region might, in some cases, increase the detrimental effect of drought on species functioning. (C) 2014 Elsevier B.V. All rights reserved.

【 授权许可】

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