tailieunhanh - Báo cáo khoa học: "Response of Pinus taeda L to soil flooding and salinity SR Pezeshki"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Response of Pinus taeda L to soil flooding and salinity SR Pezeshki. | 149 Ann Sá For 1992 49 149-159 Elsevier INRA Original article Response of Pinus taeda L to soil flooding and salinity SR Pezeshki Wetland Biogeochemistry Institute Louisiana State University Baton Rouge LA 70803 USA Received 21 August 1991 accepted 6 December 1991 Summary Seedlings of Pinustaeda L were subjected to soil flooding alone F and combined with salinity FS of 50 mol nr3. The flooding effects on soil were quantified by measuring soil redox potential. Soil redox potential remained in the range of 400 to 450 mV in control pots while it was reduced to -50 to -140 mV in flooded pots stomatai conductance g and net carbon assimilation A were reduced significantly under flooding alone and flood salt combination treatments stomatai conductance averaged 120 mmol H2O nr2 s-1 for control plants while it averaged 51 and 45 mmol H2O nr2 s-1 for flooded F and flooded plus salt FS treatments respectively. Net carbon assimilation was reduced from pmol co2 m-2 s-1 control plants to and pmol co2 m_2s-1 in F and FS plants respectively. The reductions in g and A were statistically significant. Dry weight increment per plant was reduced from g in control to and g per plant in F and FS treatments respectively. The reduction represents 59 reduction in F and 66 reduction in FS treatment. Based on the present results it is concluded that 1 p taeda showed considerable sensitivity to saltwater treatment within the range of soil anaerobiosis and salinity tested and 2 in areas where saltwater intrusion occurs frequently regeneration and survival of this species will be adversely affected. The severity of such an impact is partially dependent upon the intensity of soil reduction and the concentration of salt in floodwater. flooding forested wetlands loblolly pine I photosynthesis I salt stress stomatai conductance Résumé Réponse de Pìnus taeda L à I inondation et à la salinité. L effet d une inondation F seule OU accompagnée par la salinité 50 mol m3 sur