Figure 1 : Leaf physiological parameters in control and drought treated plants. Poplar saplings were subject to drought for 7 days. Leaf observations were made on day 0 (n =24), day 1 (n =6), day 4 (n=18), and day 7 (n=18) of (a ) Net photosynthesis (Anet , µmol m-2s-1), (b ) transpiration (E , mmol m-2 s-1), (c ) stomatal conductance (gs, mmol m-2s-1) and (d ) leaf water potential (LWP , MPa). Values are plotted as average +/- 1 standard deviation (ns indicates no statistical significance between control and drought treatments, * indicates statistically significant difference, P <0.05).