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  • 1
    ISSN: 0931-1890
    Keywords: Key words Pinus leucodermis ; Photosynthesis ; Respiration ; Nitrogen ; Chlorophyll
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Pinus heldreichii Christ is a long-lived, slow-growing Tertiary relict from the Balkans. In this study we evaluated the physiological characteristics of eight needle-age classes of P. heldreichii grown at the Arboretum of the Institute of Dendrology in Kórnik, Poland. At the end of the growing season, current-year foliage had the highest rates of mass-based light-saturated net photosynthesis (Asat) of 33.5 nmol CO2· g–1· s–1. Asat decreased with needle age, but older needle classes retained from approximately 62 to 26% of the current needles’ rate. The relationship between leaf N and chlorophyll a concentration among all needle-age classes was highly significant (r = 0.96, P = 0.0006). The variation in Asat of 1- to 7-year-old needles was linearly related to needle N concentration (r = 0.98, P = 0.0001). Needle dark respiration rates among these needle age classes ranged from 0.8 to 2.2 nmol · g–1· s–1 and decreased with needle age and nitrogen concentration. Total phenols and glucose concentrations increased linearly with needle age. A similar pattern was observed in acid buffering capacity and the pH of tissue homogenates. The water content ranged from 62% for the current needles to 51% for the 6-year-old needles. Greater investment in leaf structural tissue and increased chemical defense is associated with higher structural cost of older needles and may reduce their photosynthetic activity. Significant declines in water and nitrogen content with needle age and an increase in content of phenolics is most likely a defense adaptation of P. heldreichii related to the species’ long-lived leaves.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-2932
    Keywords: element ; needle age ; phenolics ; Pinus nigra ; pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Changes of phenolics and chemical elements [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn), iron (Fe), boron (B), copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), chromium (Cr), nickel (Ni) and cobalt (Co)] content in needles of black pine ( Pinus nigra) as dependent on age of needles (5–6 classes) and pollution were examined. The content of ortho-diphenols (o-dPh) and total phenols (TPh) was significantly higher at a polluted site than at a control one. It increased with age of needles at both sites. At the polluted site contents of N, K, Mg in black pine needles were lower and of Fe, Ni and F were higher than at the control site. An increase of content with age of needles at both sites was detected for Ca, Fe, B and F, and a decrease for N, P, K, Cu and Ni. The content of elements in different age classes of needles is connected with their mobility. The content of phenolics is negatively correlated with main nutrients and positively with some toxic elements.
    Type of Medium: Electronic Resource
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