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Diurnal changes of monoterpene fluxes in Norway spruce forest
Juráň, Stanislav ; Fares, S. ; Křůmal, Kamil ; Večeřa, Zbyněk ; Urban, Otmar
Biogenic volatile organic compounds (BVOCs) are important components of biosphere–atmosphere exchange. Their emissions depend on various meteorological parameters and stresses. Diurnal fluxes of different monoterpenes were studied within a Norway spruce (Picea abies) mountain forest to investigate their dependence on temperature and global radiation. Fluxes of monoterpenes, the most abundant BVOCs in spruce, were modelled using an inverse Lagrangian transport model, and representative diurnal variation trigged by both temperature and light was observed. This research enables future parametrization and quantification of various factors driving bidirectional fluxes.
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Convergence of morphological, biochemical, and physiological traits of upper and lower canopy of European beech leaves and Norway spruce needles within altitudinal gradients
Rajsnerová, Petra ; Klem, Karel ; Večeřová, Kristýna ; Veselá, Barbora ; Surá, Kateřina ; Rajsner, Lukáš ; Holub, Petr ; Urban, Otmar
Climatic variation along altitudinal gradients provides an excellent natural experimental set-up for investigating the possible impacts of climate change on terrestrial organisms and ecosystems. The present work has explored for the first time the acclimation of upper versus lower canopy leaves or needles in European beech (Fagus sylvatica) and Norway spruce (Picea abies) forests along an altitudinal gradient. We tested the hypothesis that restrictive climatic conditions associated with high altitudes reduce within-canopy variations of leaf traits. The investigated beech and spruce forests were located on the southern slope of the Hrubý Jeseník Mountains (Czech Republic). All measurements were taken on leaves from the upper and lower parts of the canopy of mature trees (>60 years old) growing at low (400 m a.s.l.), middle (720 m a.s.l.), and high (1,100 m a.s.l.) altitudes. Generally, we observed that with increasing altitude, which is associated with adverse microclimatic conditions, a convergence of CO2 assimilation rate and other physiological, morphological, and biochemical characteristics between the upper and lower canopy occurred. However, differences in altitudinal response among individual traits and species were found. Such plasticity in acclimation of leaves and needles has the potential to cause substantial change in the photosynthesis of individual parts of forest canopies within the vertical profile and their contribution to the overall carbon balance of vegetation.
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Changes in the photosynthetic apparatus of european beech and Norway spruce under long-term exposure to elevated CO2
Holišová, Petra ; Šprtová, Miroslava ; Kubásek, Jiří ; Lhotáková, Z. ; Mašková, P. ; Lipavská, H. ; Kočová, M. ; Holá, D. ; Radochová, Barbora ; Albrechtová, J. ; Urban, Otmar
The changes of photosynthetic performance caused by increasing CO2 concentration are refl ected at diff erent hierarchical levels of photosynthetic apparatus from the effi ciency of individual photosynthetic processes to changes in leaf structure. Th e aim of this study was to elucidate the relationships between the ultrastructure and function of photosynthetic apparatus under elevated CO2 concentration. We studied two common tree species – the European beech and the Norway spruce – grown under ambient (AC) and elevated CO2 concentrations (EC). Photosynthetic parameters were obtained using the gas-exchange system LI-6400 (LI-COR, USA). Th e characteristics of chlorophyll a fl uorescence were obtained in vivo with FluorPen FP100max (PSI, CZE) and in vitro polarographically in a suspension of isolated chloroplasts. Non-structural soluble saccharides and starch accumulation was quantifi ed using HPLC. Th e chloroplast ultrastructure was quantifi ed by stereological methods (Ellipse 2.08, SK) on the images acquired on a JEOL JEM-1011 (JEOL, JPN). Th e light-saturated CO2 assimilation rate was stimulated by EC in both species. Th e assimilation capacity of EC plants slightly decreased and was accompanied by a slight decrease in the rate of electron transport and the rate of Rubisco carboxylation. Th e growth in EC induced higher energy dissipation by light-harvesting antennae, diminished PSII activity, resulted in greater PSI capacity and in higher accumulation of starch and soluble sugars in the leaves of both species.
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Energy, carbon and economic balance of Norway spruce moncultures and near-natural forests
Plch, Radek ; Pecháček, O. ; Vala, V. ; Pokorný, Radek ; Bednář, V. ; Cudlín, Pavel
The assessment of energy, carbon and economic balances, completed by environmental load computation using the Life Cycle Assessment method, could be a useful tool for sustainable forest management examination. Th ese methods were used to compare forest stands with diff erent management in the Novohradské Mountains (Czech Republic). For this purpose, one of the main forest management set of stands in the research area was chosen. Th e diff erences between energy and carbon effi ciency were small while the diff erences between economic effi ciency were considerable for all the alternatives. From all the alternatives, higher energy, carbon and economic effi ciency for Norway spruce monoculture were achieved; however, abiotic and biotic disturbances have not been included in the calculation yet. Th e main part of energy inputs and carbon emission consists of silviculture and timber transport.
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