tailieunhanh - Báo cáo khoa học: "Does bulk-needle δ13C reflect short-term discrimination"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Does bulk-needle δ13C reflect short-term discrimination?. | 135 Ann. For. Sci. 58 2001 135-141 INRA EDP Sciences 2001 Original article Does bulk-needle Ỗ13C reflect short-term discrimination Oliver Brendel Cellular and environmental physiology CEP Scottish Crop Research Institute SCRI Invergowrie Dundee dD2 5DA Scotland UK Received 28 February 2000 accepted 6 November 2000 Abstract - When bulk needle material is analysed for its carbon isotope signal the net s 13C underlies variation of the biochemical composition of the needle. Bulk needle material can be categorized into two different types of carbon pools differing in the time period of assimilation structural carbon and carbon with a rapid turnover. The bulk needle s 13C is influenced by the relative amounts of the two pools. In the present study the s 13C of rapid turnover carbon was estimated using gas exchange measurements. When these were compared to the respective bulk needle s 13C a significant linear correlation was found raw data p R1 2 daily means p R2 indicating that the rapid turnover carbon pool influences the overall s 13C. Therefore one has to be aware that bulk-needle s 13C measurements can have the tendency either toward reflecting the s 13C of structural carbon or toward reflecting the s 13C of rapid turnover carbon. needle discrimination carbon isotope gas exchange Pinus sylvestris Résumé - Le S13C des aiguilles de pin sylvestre reflète-t-il la discrimination isotopique à court terme La composition iso-topique en carbone des aiguilles entières depend partiellement de leur composition biochimique. Le carbone d une aiguille peut être représenté en deux reservoirs incorporés à des périodes differentes dans la vie de l aiguille le carbone structural et le carbone à rotation rapide. s 13C de l aiguille est influencé par les équilibres entre les deux pools. s 13C du pool de carbone à rotation rapide a été estimé par des mesures d échanges gazeux et comparée à celle du carbone total des aiguilles correspondantes. Une correlation linéaire