Foliage of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings from xeric and mesic environments was sampled during two induced, consecutive, drought cycles to determine relationships among leaf resistance, plant water potential, and abscisic acid (ABA) concentration. One group of seedlings was placed in a growth room; the other was kept outside at a nursery under natural conditions. During the first drought cycle, seedlings transpired similarly. During the second drought, xeric seedlings in the growth room and nursery initiated stomatal closure at greater levels of plant moisture stress (PMS) than in the first drought cycle, but stomatal behavior of mesic seedlings was unchanged. During the first drought cycle, a sharp increase in ABA concentration in both ecotypes coincided with increased leaf resistance within a narrow water-potential range. However, after xeric seedlings were rewatered and then subjected to drought, leaf resistances remained low even though the previous threshold PMS and ABA concentrations for stomatal closure were reached. For mesic seedlings in the growth room, ABA concentrations remained high after rewatering and slowly decreased with time, although recovery to predrought leaf resistances was largely completed 2 days after rewatering.