Effects of Drought Stress and Ca Supply on the Biomass Allocation Strategies of Poplar and Mulberry

In order to investigate the effect of Ca on biomass allocation strategies tree species with different growth rates under drought conditions, we treated poplar (Populus canadensis cv) cuttings and mulberry (Morus alba) seedlings two soil moisture levels (40 ± 5% 80 maximum water holding capacity) (0 200 mg·kg−1 Ca2+) in a greenhouse experiment, then measured uptake, growth, gas exchange parameters, allocation, leaf traits. Drought induced reduction accumulation seedlings, exhibited patterns response stress. Under Ca0 treatment, allocated more leaves less stems leading an increased leaf/stem (L/St) ratio higher SLA than moist conditions maintain Pn, had enhanced WUE cope same roots stems, root/shoot (R/S) lower SLA, improve resistance. Ca200 treatment decreased whereas it WUE, root R/S alleviated stress both species.