Compared sensitivity of seedlings from 3 woody species (Quercus robur L, Quercus rubra L and Fagus silvatica L) to water-logging and associated root hypoxia: effects on water relations and photosynthesis

Erwin E. Dreyer (1)

1 Unité d'Écophysiologie forestière

Seedlings of Quercus robur, Q rubra and Fagus silvatica were submitted to a period of partial (water table at 6 cm below ground) or total water-logging for 4 weeks. Important disorders were induced by the latter treatment in growth (root decay, partial leaf wilting), water relations (decreased predawn water potential) and photosynthesis (stomatal closure, reduced net assimilation rates, lowered O2 evolution under saturating CO2 and irradiance, and limited photochemical efficiency of PS II). It has been concluded that the observed stomatal closure was accompanied by strong disorders at chloroplast level, which happened without visible waterlogging-induced deficiencies in mineral nutrient supply. Reactions to partial water-logging were much more limited. F silvatica displayed the strongest disorders in response to both treatments, Q robur showed only slight stress effects in response to partial water-logging and Q rubra had intermediate behaviour. These observations are in agreement with the reported differences in sensitivity to water-logging of adult trees in the stand. The precise chain of events leading to these disorders in the shoots of water-logged seedlings remains to be elucidated.

Mots clés: conductance stomatique; conductance hydraulique; nutrition minérale; photochimie; photosystème II

Domaines: Sciences agricoles

Erwin E. Dreyer. Compared sensitivity of seedlings from 3 woody species (Quercus robur L, Quercus rubra L and Fagus silvatica L) to water-logging and associated root hypoxia: effects on water relations and photosynthesis. Annales des sciences forestières, 1994, 51 (4), pp.417-429. ⟨10.1051/forest:19940407⟩. ⟨hal-01001194⟩