caa a22 4500 469098112 CHVBK 20180323133037.0 cr unu---uuuuu 170328e19920801xx s 000 0 eng 10.1007/BF00317782 doi (NATIONALLICENCE)springer-10.1007/BF00317782 Is long-lived foliage in Picea mariana an adaptation to nutrient-poor conditions? [Elektronische Daten] [Ken Greenway, S. Macdonald, Victor Lieffers] Summary: This study evaluated the contribution of different ages of foliage to the nutrient and carbon balance of black spruce (Picea mariana (Mill.) B.S.P.) from a nutrient-poor peatland in Alberta. Seasonal patterns of foliar nitrogen and phosphorus concentration and content were examined in six needle cohorts up to 10 years old. Trees were treated to simulate excess nutrient deficiency (removal of all one-year-old foliage), nutrient excess (fertilized with 250, 50, 100 kg ha−1 NPK split application in June and July), or left as controls. Gas exchange (net assimilation-Na, stomatal conductance-gs, mesophyll conductance-gm, water-use efficiency-WUE, dark respiration-RS) was measured on six different needle cohorts in several control trees in 1989 and 1990. Nitrogen and phosphorus concentration decreased with needle age. Foliar nutrient concentration fell from April to June and then was stable until September except for the fertilized trees where it increased. There was no evidence of greater than normal retranslocation of nutrients from older needles for defoliated trees or greater than normal nutrient loading in older needles of fertilized trees. NA, gs, gm, WUE, and RS were similar for all needles up to six or eight years old, these older needles having NA of 65% of current needles and similar RS. The results do not support to conclusion that older needles of black spruce are retained as an adaptation to nutrient stress. It does not appear that older needles serve as a nutrient storage site in conditions of excess nutrient availability or a greater than normal nutrient source during times of excess nutrient deficiency. It appears that the maintenance of long-livedfoliage in black spruce does not provide for greater flexibility in tree nutrient allocation. Their contribution to the carbon balance of the tree seems to be sufficient to explain their retention. Springer-Verlag, 1992 Foliar nutrient retranslocation nationallicence Needle age nationallicence Photosynthesis nationallicence Nitrogen nationallicence Phosphorus nationallicence Respiration nationallicence Greenway Ken Department of Forest Science, University of Alberta, T6G 2H1, U, Edmonton, Alberta, Canada aut Macdonald S. Department of Forest Science, University of Alberta, T6G 2H1, U, Edmonton, Alberta, Canada aut Lieffers Victor Department of Forest Science, University of Alberta, T6G 2H1, U, Edmonton, Alberta, Canada aut Oecologia Springer-Verlag 91/2(1992-08-01), 184-191 0029-8549 91:2<184 1992 91 442 https://doi.org/10.1007/BF00317782 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00317782 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Greenway Ken Department of Forest Science, University of Alberta, T6G 2H1, U, Edmonton, Alberta, Canada aut NATIONALLICENCE 700 1- Macdonald S. Department of Forest Science, University of Alberta, T6G 2H1, U, Edmonton, Alberta, Canada aut NATIONALLICENCE 700 1- Lieffers Victor Department of Forest Science, University of Alberta, T6G 2H1, U, Edmonton, Alberta, Canada aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 91/2(1992-08-01), 184-191 0029-8549 91:2<184 1992 91 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer