tailieunhanh - Báo cáo lâm nghiệp: "Effect of initial height of seedlings on the growth of planting material of Norway spruce (Picea abies [L.] Karst.) in mountain conditions"

Tham khảo luận văn - đề án 'báo cáo lâm nghiệp: "effect of initial height of seedlings on the growth of planting material of norway spruce (picea abies [l.] karst.) in mountain conditions"', luận văn - báo cáo phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | JOURNAL OF FOREST SCIENCE 55 2009 3 112-118 Effect of initial height of seedlings on the growth of planting material of Norway spruce Picea abies L. Karst. in mountain conditions A. Jurasek J. Leugner J. Martincová Forestry and Game Management Research Institute Strnady Opocno Research Station Opocno Czech Republic ABSTRACT Common ways of nursery cultivation and sorting the planting material of mountain provenances of Norway spruce Picea abies L. Karst. are connected with the risk of undesirable narrowing of the genetic spectrum of populations. Investigations in spruce plantations established by different planting materials found out very good growth total height is 125 cm 9 years after outplanting and health status of these slowly growing seedlings planted in extreme mountain conditions. In order to prevent the genetic spectrum narrowing we recommend to cultivate all seedlings including smaller outsorted commonly culled ones. The smallest seedlings can be grown one year longer and subsequently planted out in the same locality as the remaining planting material of the same seed lot. Keywords Norway spruce mountain conditions mountain populations reforestation The reforestation of exposed mountain localities is more difficult than current forest regeneration at lower locations. The growing season in the mountains is shorter with lower temperatures and long-lasting snow cover. Young trees may often be deformed and damaged by slides of snow layers in the course of thaw. Shoots projecting over the snow cover are damaged mechanically by snow and ice particles drifted by the wind. In bright weather when the soil is still too cold and the roots cannot take up water sufficiently there occurs physiological winter drying up of sunlit shoots. Temperature extremes in the form of late or early frosts are also frequent. Specific mountain conditions make greater demands on the choice and preparation of planting material that will survive and grow in such a frequently extreme .