Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế, đề tài: " Radial growth of mature pedunculate and sessile oaks in response to drainage, fertilization and weeding on acid pseudogley soils. | Ann Sci For 1996 53 585-594 Elsevier INRA 585 Original article Radial growth of mature pedunculate and sessile oaks in response to drainage fertilization and weeding on acid pseudogley soils M Becker G Levy Y Lefevre Forest Ecophysiology Unit INFIA 54280 Champenoux France Received 30 November 1994 accepted 21 June 1995 Summary In northeastern France forest soils on old alluvial terraces are generally unfavourable strongly acid and often characterized by superficial temporary water tables. In this case the ground vegetation is dominated by a dense cover of Carex brizoides on the moderately hydromorphic soils Carex site or Molinia caerulea on the strongly hydromorphic soils Molinia site . Both pedunculate and sessile oaks are present in the Molinia site and practically only pedunculate oak in the Carex site. The experiment aimed at quantifying the radial growth response of mature oaks to various silvicultural interventions. It included i ditching in order to drain the soils in 1974 ii herbicide application glyphosate in 1981 and iii fertilization P K Ca and Mg in 1982 N in 1982 and 1985 . A dendrochronological investigation was performed on 620 adult oaks from 60 to 200 years old which were subjected to these treatments alone or in combination. The results refer to basal area increment by comparison with control trees. The effect of drainage depended on the site type the oak species and the age of the trees. Drainage had practically no effect in the Carex site. In the Molinia site the effect was positive 20 for the young 110 years old sessile oaks only. It became even depressive -15 for the old 110 years old pedunculate oaks. The effect of weeding differed according to the site type the age of the trees and the drainage modality. Whatever the drainage modality the effect was depressive -13 for the young trees and nonsignificant for the old ones in the Carex site. There was a positive interaction between weeding and drainage in the Molinia site in the old trees 22 as
