Above-ground space sequestration determines competitive success in juvenile beech and spruce trees

• Published in: The New phytologist Vol. 167; no. 1; pp. 181 - 196
• Main Authors: Kozovits, A.R, Matyssek, R, Winkler, J.B, Gottlein, A, Blaschke, H, Grams, T.E.E
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science 01.07.2005; Blackwell Science Ltd; Blackwell
• Subjects: Aboveground biomass; air pollution; allometry; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Biomass; Carbon; Carbon - metabolism; Carbon Dioxide; competition; Competitiveness; Cost efficiency; cost–benefit relations; Demecology; Demography; ecological succession; elevated carbon dioxide; Fagus; Fagus - growth & development; Fagus - physiology; Fagus sylvatica; Fagus sylvatica (beech); forest ecosystems; forest trees; Fundamental and applied biological sciences. Psychology; growth & development; interspecific competition; intraspecific competition; Leaves; metabolism; Ozone; ozone (O3); physiology; Phytotrons; Picea; Picea - growth & development; Picea - physiology; Picea abies; Picea abies (spruce); plant growth; Plant Leaves; Plant Leaves - physiology; Plant Roots; Plant Roots - physiology; Plant Shoots; Plant Shoots - physiology; Plants; Plants and fungi; pollutants; resource investment; Seasons; Picea abies (spruce); Growth; Resource allocation; Carbon dioxide; competition; Biomass; Allometry; Medium enrichment; elevated carbon dioxide; Dicotyledones; ozone (O3); Angiospermae; Softwood forest tree; Gymnospermae; Interspecific competition; Hardwood forest tree; Ozone; Fagaceae; Stress; cost-benefit relations; Fagus sylvatica (beech); Intraspecific competition; Coniferales; Spermatophyta; resource investment; Picea abies; Interspecific relation; Fagus sylvatica
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2005.01391.x

$\bullet$ A 2-yr phytotron study was conducted to investigate the intra- and inter-specific competitive behaviour of juvenile beech (Fagus sylvatica) and spruce (Picea abies). Competitiveness was analysed by quantifying the resource budgets that occur along structures and within occupied space of relevance for competitive interaction. $\bullet$ Ambient and elevated CO2 and ozone (O3) regimes were applied throughout two growing seasons as stressors for provoking changes in resource budgets, growth and allocation to facilitate the competition analysis. The hypothesis tested was that the ability to sequester space at low structural cost will determine the competitive success. $\bullet$ Spruce was a stronger competitor than beech, as displayed by its higher above-ground biomass increments in mixed culture compared with monoculture. A crucial factor in the competitive success of spruce was its ability to enlarge crown volume at low structural costs, supporting the hypothesis. $\bullet$ Interspecific competition with spruce resulted in a size-independent readjustment of above-ground allocation in beech (reduced leaf : shoot biomass ratio). The efficient use of resources for above-ground space sequestration proved to be a parameter that quantitatively reflects competitiveness.