Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Why do large, nitrogen rich seedlings better resist stressful transplanting conditions? A physiological analysis in two functionally contrasting Mediterranean forest species
AU - Cuesta, Barbara
AU - Villar-Salvador, Pedro
AU - Puertolas Simon, Jaime
AU - Jacobs, Douglass F.
AU - Rey Benayas, Jose M.
PY - 2010/6/15
Y1 - 2010/6/15
N2 - We analysed the physiological bases that explain why large and high nitrogen (N) concentration seedlings frequently have improved survival and growth relative to small seedlings in Mediterranean woodland plantations. Large seedlings of Aleppo pine (Pinus halepensis Mill.) and holm oak (Quercus ilex L) with high N concentration (L+), and small seedlings with either high (S+) or low (S-) N concentration, were planted on two sites of different weed competition intensity that created contrasting stress conditions. Seedling survival, growth, gas exchange, N remobilization (N(R)) and uptake (N(U)), and water potential were assessed through the first growing season. Weeds reduced survival and growth, but seedling response to weed competition varied among phenotypes and between species. At the end of the first growing season, L+ Aleppo pine seedlings had higher survival than both small seedling types in presence of weeds but no differences were observed in absence of weeds. Mortality differences among phenotypes occurred in spring but not in summer. L+ Aleppo pines grew more than small Aleppo pines independently of weed competition. No holm oak seedling type survived in presence of weeds and no mortality differences among phenotypes where observed in absence of weeds, although L+ holm oak seedlings grew more than small seedlings. Mortality and growth differences in Aleppo pine were linked to marked physiological differences among phenotypes while physiological differences were small among holm oak phenotypes. L+ Aleppo pines had greater root growth, gas exchange. N(R), and N(U) than small seedlings, irrespective of their N concentration. Seedling size in Aleppo pine had a greater role in the performance of transplanted seedlings than N concentration. The functional differences among oak phenotypes were small whereas they were large in pine seedlings, which led to smaller differences in transplanting performance in holm oak than in pine. This suggests that the nursery seedling quality improvement for planting in dry sites could depend on the species-specific phenotypic plasticity and functional strategy. Improved transplanting performance in large Aleppo pine seedlings relative to small seedlings was linked to greater gas exchange, root growth and N cycling. (C) 2010 Elsevier B.V. All rights reserved.
AB - We analysed the physiological bases that explain why large and high nitrogen (N) concentration seedlings frequently have improved survival and growth relative to small seedlings in Mediterranean woodland plantations. Large seedlings of Aleppo pine (Pinus halepensis Mill.) and holm oak (Quercus ilex L) with high N concentration (L+), and small seedlings with either high (S+) or low (S-) N concentration, were planted on two sites of different weed competition intensity that created contrasting stress conditions. Seedling survival, growth, gas exchange, N remobilization (N(R)) and uptake (N(U)), and water potential were assessed through the first growing season. Weeds reduced survival and growth, but seedling response to weed competition varied among phenotypes and between species. At the end of the first growing season, L+ Aleppo pine seedlings had higher survival than both small seedling types in presence of weeds but no differences were observed in absence of weeds. Mortality differences among phenotypes occurred in spring but not in summer. L+ Aleppo pines grew more than small Aleppo pines independently of weed competition. No holm oak seedling type survived in presence of weeds and no mortality differences among phenotypes where observed in absence of weeds, although L+ holm oak seedlings grew more than small seedlings. Mortality and growth differences in Aleppo pine were linked to marked physiological differences among phenotypes while physiological differences were small among holm oak phenotypes. L+ Aleppo pines had greater root growth, gas exchange. N(R), and N(U) than small seedlings, irrespective of their N concentration. Seedling size in Aleppo pine had a greater role in the performance of transplanted seedlings than N concentration. The functional differences among oak phenotypes were small whereas they were large in pine seedlings, which led to smaller differences in transplanting performance in holm oak than in pine. This suggests that the nursery seedling quality improvement for planting in dry sites could depend on the species-specific phenotypic plasticity and functional strategy. Improved transplanting performance in large Aleppo pine seedlings relative to small seedlings was linked to greater gas exchange, root growth and N cycling. (C) 2010 Elsevier B.V. All rights reserved.
KW - QUERCUS-ILEX
KW - Photosynthesis
KW - Water potential
KW - Survival
KW - Pinus halepensis
KW - Stomatal conductance
KW - HERBACEOUS VEGETATION
KW - Quercus ilex
KW - CARBON-DIOXIDE CONCENTRATION
KW - WATER RELATIONS
KW - PINUS-HALEPENSIS
KW - PLANTATION ESTABLISHMENT
KW - Root growth
KW - FIELD PERFORMANCE
KW - Nitrogen remobilization
KW - STOMATAL CONDUCTANCE
KW - LOBLOLLY-PINE
KW - ROOT-GROWTH
KW - Competition
U2 - 10.1016/j.foreco.2010.04.002
DO - 10.1016/j.foreco.2010.04.002
M3 - Journal article
VL - 260
SP - 71
EP - 78
JO - Forest Ecology and Management
JF - Forest Ecology and Management
SN - 0378-1127
IS - 1
ER -