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Space-related Resource Investments and Gains of Adult Beech (Fagus sylvatica) and Spruce (Picea abies) as a Quantification of Aboveground Competitiveness 
Übersetzter Titel:
Raumbezogene Gewinne und Investitionen von Resourcen in Buche (Fagus sylvatica) und Fichte (Picea abies) zur Quantifizierung oberirdischen Konkurrenzverhaltens 
Fakultät Wissenschaftszentrum Weihenstephan 
Matyssek, Rainer (Prof. Dr.) 
Matyssek, Rainer (Prof. Dr.); Schnyder, Johannes (Prof. Dr.); Beyschlag, Wolfram (Prof. Dr.) 
BIO Biowissenschaften; FOR Forstwissenschaften 
Norway spruce; Picea abies; European beech; Fagus sylvatica; stand; tree; branch; leaf; specific leaf area; carbon gain; photosynthesis; model; PSN6; scaling; allocation; partitioning; respiration; branch respiration; growth; carbon balance; light; vertical profile; leaf area index; LAI; leaf area density; gap fraction; efficiency; crown space; crown volume; competitiveness; space sequestration; space occupation; space exploitation; running costs; mature trees; ozone; O3; free-air fumigation; Kr...    »
Übersetzte Stichworte:
Gemeine Fichte; Picea abies; Rotbuche; Fagus sylvatica; Bestand; Baum; Zweig; Blatt; spezifische Blattflaeche; Kohlenstoff-Gewinn; Photosynthese; Modell; PSN6; Skalierung; Allokation; Atmung; Zweigatmung; Respiration; Zuwachs; Kohlenstoffbilanz; Licht; vertikales Profil; Blatttflaechenindex; LAI; Blattflaechendichte; Lueckenanteil; Effizienz; Kronenraum; Kronenvolumen; Konkurrenzverhalten; Konkurrenzkraft; Raumbesetzung; Raumausnutzung; Unterhaltskosten; Ozon; O3; free-air Begasung; Kranzberger...    »
FOR 180d; BIO 420d 
In a field study, cost-benefit relationships of aboveground resource allocation were analysed in branches of Norway spruce (Picea abies [L.] Karst.) and European beech (Fagus sylvatica L.). The study identified response patterns in allocation of resources under different light conditions in both species. It was postulated that resource investment and gains based on crown volume have the potential to quantitatively describe the plant’s competitive ability (i.e. competitiveness). Three cost-benefit ratios (efficiencies) were defined to compare trees of contrasting growth form and leaf type, thereby considering metabolic processes involved in C allocation (Grams et al. 2002): (1) Efficiency of space sequestration (occupied aboveground or belowground space per unit of resource investment), (2) efficiency of space exploitation (resource gain per unit of aboveground or belowground space) and (3) efficiency of “running costs” (in terms of occupied aboveground or belowground space per unit of respiration or transpiration). This study was conducted within the framework of a collaborate research program with the title “Sonderforschungsbereich 607: Growth and Parasite Defense - Competition for Resources in Economic Plants from Agronomy and Forestry” funded by the ‘Deutsche Forschungsgemeinschaft’, project SFB 607-B4. Ten spruce and ten beech trees within a mixed forest stand “Kranzberger Forst” north of Munich/ Germany were investigated for two years (1999-2000). In each tree a study branch from the upper sun and from the lower shade crown were chosen to cover the range of morphological and physiological variability within individual trees. The crown volume occupied by a branch was approximated based on a frustrum model enveloping the foliage of the branch. Assessment of crown volume was readily performed, low?cost and uncomplicated to calculate. Biomass of foliage and axes of each study branch was monitored non?destructively by means of allometric relationships, derived and validated on comparable harvested trees. CO2 and H2O leaf gas exchange was analysed with a portable infrared gas exchange system throughout the annual course by measuring light & CO2 dependencies and respiration. Gas exchange data was used to parameterise a leaf gas exchange model. The annual gas exchange was calculated in ten-minute intervals based on microclimate (light from four sensors per branch, temperature, humidity, and CO2 concentration), and was scaled biometrically to the branch level. A custom made system was developed to continuously measure respiration of axes. Respiration was scaled dependent on temperature to the surface area of the whole branch. Ozone was applied in the second year of investigation as an experimental tool to chronically disturb the homeostasis of resource allocation within branches. Whole crowns of five spruce and five beech study trees were fumigated with twice ambient ozone. Leaf area and mass distribution was derived from optical measurements of leaf area index in the vertical profile within the stand. Growth form and foliage type are contrasting in the coniferous and evergreen spruce and the deciduous and broadleaved beech. Still, it could be shown that the annual gross carbon gain was very similar in adult trees of spruce and beech when related to units of foliated space. Running costs of transpiration and respiration were also rather similar in this aspect. Apparently, differences in leaf level characteristics can vanish when relating physiological performance to space. The annual gross carbon gain scaled from branch to the stand level of spruce and beech showed good agreement to studies of gross primary production in forest stands. The annual carbon balance was negative in all investigated shade branches of beech and in part of the shade branches of spruce. Some of these branches were sustained by the trees over years. This contradicts the ‘theory of branch autonomy’ and is not a common finding, as it probably occurs in branches within the lower shade crown of shade-tolerant species only. The light compensation point of the carbon balance was at lower light availability in beech than in spruce branches, which is of advantage for growth and persistence of shade branches and subordinate individuals of beech. On the stand level, the annual carbon balance was deteriorated in spruce due to negative carbon balances. In beech, the fraction of shade branches with a negative carbon balance was small and therefore the carbon balance was affected to a minor extent compared to spruce at the stand level. Predominantly, spruce and beech were different in their efficiencies of space sequestration. Sun branches of spruce compared to beech sequestered crown volume with lower carbon investments of foliage and axes. This seems more advantageous to spruce during undisturbed growth of a stand as by sequestration of the same amount of space and inherently a similar carbon gain, a higher proportion of carbon than in beech sun branches remains that can be allocated to stem and roots. This was in line with published findings, where spruce was reported to dominate over beech through faster growth in southern Germany including the study site ‘Kranzberger Forst’. However, the relative annual increment of crown volume was larger in sun branches of beech than in spruce. This can be of advantage to beech e.g. in disturbed environments with new gap formation in the canopy. However, losses of invested carbon through the direct interaction of swaying tree crowns were considerably higher in beech compared to spruce trees. The lost carbon mass was equivalent to a loss of a similar amount of space in both species. It appears that larger gap size with decreasing potential of crown abrasion is important for beech to benefit through a rapid volume increment. The disturbance of spruce and beech through elevated ozone concentrations had not taken effect on the efficiency of space sequestration within one season of fumigation, which confirms the findings of other studies. Different strategies of space sequestration determined competitiveness in this study. This was also concluded in a study of hedgerow-species differing in successional status and in a phytotron study with competition among young trees. In general, space-related efficiencies have the power to address competitiveness quantitatively, which allows comparison of contrasting species. It is encouraged to include space-related resource gains and investments in competition studies as space appears to be a resource itself and object of competitive interactions. The transfer and the expansion of space?related analysis to studies of e.g. responses in different environments, interactions in herbaceous and woody plants, belowground interactions or invading neophytes, is very promising, as new insights and understanding of the processes can be expected that determine competitiveness of species and individual plants. 
Übersetzte Kurzfassung:
In einem Mischbestand wurden Kosten-Nutzen Bilanzen der oberirdischen Ressourcen-Allokation analysiert. An Zweigen von Fichte (Picea abies [L.] KARST.) und Rotbuche (Fagus sylvatica L.) wurden Muster in der Veränderung der Ressourcen-Allokation unter verschiedenen Lichtbedingungen ermittelt. Der Versuchsansatz basierte darauf, dass Ressourcen-Investitionen und -gewinne im Bezug auf einen besetzten Kronenraum, das Konkurrenzverhalten von Pflanzen quantitativ wiedergeben. Dazu wurden drei Qutotien...    »
Universitätsbibliothek der TU München 
Mündliche Prüfung:
Mischwald Fichte Rotbuche Wettbewerbsverhalten Licht Kronendach Ressourcenallokation Quantitative Methode 
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