Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Differences in drought resistance among 3 deciduous oak species grown in large boxes. | 221 Ann Sci For 1993 50 221-233 Elsevier INRA Original article Differences in drought resistance among 3 deciduous oak species grown in large boxes p Vivin 1 G Aussenac 1 G Levy 2 INRA Nancy Laboratoire de Bioclimatologie et Écophysiologie Forestiere Champenoux 2INRA Nancy Laboratoire Sol et Nutrition Unite d Ecophysiologie Forestiere 54280 Champenoux France Received 7 October 1992 accepted 18 February 1992 Summary The purpose of this study was to explain large differences in growth and decline of the pedunculate oak Quercus robur L and the sessile oak O petraea Liebl observed in the forest as a result of drought. In addition northern red oak O rubra L was compared with the 2 indigenous oaks. The effects of controlled soil water deficits on growth and water relations of young plants of these 3 species grown in large boxes have been studied. The plants were old enough to have developed normal root systems. Two species were planted in each box and submitted to very similar patterns of water stress. Predawn leaf water potential stomatai conductance net assimilation rates shoot elongation and mortality were monitored. The effect of an overall improvement in mineral nutrition on these parameters was also tested. During water deficit decrease in predawn leaf water potential the pattern of decrease of gas exchange was similar for the 3 species. Thus their ability to limit water deficit by reduction of transpiration was similar. On the other hand shoot growth of o rubra was more reduced than that of o robur for similar predawn leaf water potential growth of Q pe-traea was the least sensitive. However increase of mineral nutrition improved the growth of both Q robur and Q rubra but not that of o petraea. For the 3 species no mortality was noted as long as predawn leaf water potentials remained MPa. Below this limit the mortality rate was highest in o robur Q petraea and lowest in Q rubra. These differences in mortality between species are due to differences in .
