tailieunhanh - Báo cáo khoa học: "Estimation of clonal contribution to cone and seed crops in a Sitka spruce seed orchard"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Estimation of clonal contribution to cone and seed crops in a Sitka spruce seed orchard. | Ann Sci For 1993 50 461-467 Elsevier INRA 461 Original article Estimation of clonal contribution to cone and seed crops in a Sitka spruce seed orchard K Chaisurisri 1. YA El-Kassaby 1 Faculty of Forestry University of British Columbia Vancouver BC V6T 1Z4 2 Pacific Forest Products Ltd Saanich Forestry Centre 8067 East Saanich Fid RR 1 Saanichton BC VOS 1M0 Canada Received 17 November 1992 accepted 12 May 1993 Summary The relationship between reproductive energy and reproductive success and its impact on parental balance were studied in a clonal Sitka spruce Picea sitchensis Bong Carr seed orchard over 2 crop-years. Parental reproductive output and effective female population number estimates gave a good indication of the parental imbalance in the orchard crops however they did not show the existing differences in reproductive energy and reproductive success among the studied clones. Parental balance estimates based on seed data were more accurate than those based on cone counts. The orchard s parental balance showed consistent improvement over time. Two management options namely supplemental-mass-pollination and harvesting the cone crop by subsets of cone production level were proposed to alleviate parental imbalance. Sitka spruce seed orchard parental balance effective population number reproductive energy reproductive success Résumé Estimation de la contribution clonale à la production de cones et de graines dans un verger à graines d épicéa de Sitka. Get article étudie les relations entre énergie reproductive nombre de cones produits par un arbre et succès reproductif nombre de graines produites . L im-pact de ces 2 facteurs sur la contribution de chaque clone à la production de graines d un verger d épicéa de Sitka durant 2 années successives est égatement abordé. Les estimations du nombre efficace d arbres mères rendent bien compte de la contribution très inégale des diffdrents clones à la production de graines. Cependant elles ne mettent pas en évidence .