Stress responses in Salix gracilistyla cuttings subjected to repetitive alternate flooding and drought

Abstract

To determine the tolerance of Salix gracilistyla to repetitive alternate flooding and drought, we measured leaf stomatal conductance, pre-dawn water potential, osmotic adjustment, and biomass production under greenhouse conditions. We used a control and nine crossed treatments (F1-D1-F3-D3) in which we combined 1-, 2-, or 3-week floodings (F) and droughts (D). Leaf stomatal conductance was lowest in 3 weeks of flooding or drought when the preceding event (flood or drought) was also of a 3-week duration. Leaf pre-dawn water potential was reduced in 3 weeks of drought when preceded by 2 or 3 weeks of flooding. Cuttings had slight osmotic adjustments in repetitions of long floodings and droughts. During longer durations of drought in crossed experiments, plants had low root and shoot mass, few hypertrophic lenticels, and reduced leaf mass; when flooding duration increased in crossed experiments, root mass was reduced, there were more hypertrophic lenticels, and the leaf area was reduced. Cuttings achieved stress tolerance by inhibition of transpiration, osmotic adjustment, reduction of transpiration area, and development of hypertrophic lenticels. Stress tolerance was weak when repetitive 2-or 3-week floodings were combined with 3-week droughts. The duration of flooding and drought periods under which S. gracilistyla achieves stress tolerance may be critical in determining distributions along riverbanks.

Stress responses of Salix gracilistyla and Salix subfragilis cuttings to repeated flooding and drought

“…leaf mass, leaf size, leaf mass per area; Metcalfe et al 1990), which reduces the risk of wood embolism. The duration of drought affects the leaf mass and size of S. gracilistyla cuttings when a 3-week flooding and 3-week drought regime is repeated (Nakai et al 2010). A 2-week drought affects the growth of cuttings: the midday stomatal conductance of S. gracilistyla under 2-week drought treatment declined to approximately half that of the control (Nakai et al 2010).…”

“…The duration of drought affects the leaf mass and size of S. gracilistyla cuttings when a 3-week flooding and 3-week drought regime is repeated (Nakai et al 2010). A 2-week drought affects the growth of cuttings: the midday stomatal conductance of S. gracilistyla under 2-week drought treatment declined to approximately half that of the control (Nakai et al 2010). Furthermore, Ww pd , pre-dawn leaf water potential at the end of the first or second cycle of drought treatments; Ww tlp , water potential at turgor loss point; Wo sat , osmotic potential at full turgor; F, duration of flooding treatment; D, duration of drought treatment; S, species many shoots of S. subfragilis cuttings died when flooding and 3-week drought regimes were repeated (Nakai, unpublished data).…”

Reduction of photosynthesis before midday depression occurred: leaf photosynthesis of Fagus crenata in a temperate forest in relation to canopy position and a number of days after rainfall

“…Tazaki et al (1980) reported that upper leaves of mulberry tree showed no midday depression in the second day after the last rainfall, but apparent depression occurred in the eighth day. Nakai et al (2010) also reported in the experiment of Salix gracilistyla cuttings, that the longer the drought treatment, the more stomatal limitation on photosynthesis. However, those studies did not investigate the difference of stomatal limitation between canopy positions.…”

Flooding tolerance in four ‘Garrigue’ landscape plants: Implications for their future use in the urban landscapes of north-west Europe?

“…Flooding can induce leaf water deficit in a similar manner to drought stress although the response is not universal (Else et al, 2009). As flooding can induce physiological 'drought', it is logical to assume that some of the acclimation responses to water shortage and flooding may have some commonality (He et al, 2012;Nakai, Yurugi, & Kisanuki, 2010). In Zea mays, for example, drought tolerant cultivars also conferred greater tolerance to waterlogging, due to greater water use efficiency and lower shoot to root ratios (Grzesiak, Hura, Grzesiak, & Pieńkowski, 1999); Eucalyptus camaldulensis shows greater adaptability to both drought and waterlogging compared to E. globulus (Sena Gomes & Kozlowski, 1980).…”