Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế, đề tài: "Intra- and interannual variations of transpiration, leaf area index and radial growth of a sessile oak stand (Quercus petraea). | 521 Ann Sci For 1996 53 521-536 Elsevier INRA Original article Intra- and interannual variations of transpiration leaf area index and radial growth of a sessile oak stand Quercus petraea N Bréda A Granier Équipe bioclimatologie et écophysiologie forestiere Unite d ecophysiologie forestiere Centre de Nancy Inra 54280 Champenoux France Received 15 December 1994 accepted 19 June 1995 Summary Bud-burst leaf area index LAI transpiration soil water content and radial growth of a 35-year-old Quercus petraea stand were measured during 5 successive years 1989-1993 . At the beginning of 1992 half of the stand was thinned. The increase of stand transpiration during spring was linearly correlated to the development of LAI. During the second part of the season although LAI continued to increase because of rhythmic shoot development transpiration was strongly reduced as soil water content decreased. The transpiration potential evapotranspiration T PET ratio decreased sharply as soon as relative extractable water REW dropped below . Likewise cumulated stand transpiration varied among years because of variability in soil water availability LAI and canopy structure. A linear relationship similar to the one observed for weekly variations was noted between T PET and LAI maximum LAI ranged from to 6 in this ring-porous species. Seasonal circumference measurements showed that 43 of the annual increment was achieved before leaf development hence before canopy transpiration and cc 2 assimilation were started. Tree ring area was significantly correlated to the cumulated transpiration a water-use efficiency variable was defined at both tree and stand level. transpiration leaf area index I drought circumference increment Quercus petraea Resume Variations intra- et interannuelles de transpiration d indice foliaire et de croissance radiale d un peuplement de chêne sessile Quercus petraea . Le débourrement I indice foliaire LAI la transpiration la teneur en eau du sol et la croissance .
