Morphological plasticity of regeneration subject to different levels of canopy cover in mixed-species, multiaged forests of the Romanian Carpathians

• Published in: Trees (Berlin, West) Vol. 20; no. 2; pp. 196 - 209
• Main Authors: Stancioiu, P.T, O'Hara, K.L
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.03.2006; Springer Nature B.V
• Subjects: Abies alba; Animal and plant ecology; Animal, plant and microbial ecology; basal area; Biological and medical sciences; Canopies; canopy; Carpathian Mountains; Carpathian region; Fagus sylvatica; Fagus sylvatica subsp. sylvatica; forest regeneration; forest stands; forest trees; Forests; Fundamental and applied biological sciences. Psychology; Herbivores; leaf area; leaves; Light; light intensity; mixtures; Mountains; overstory; Picea abies; Pine trees; plant morphology; Plasticity; probability; Romania; saplings; Seedlings; shade tolerance; Shoots; solar radiation; stand basal area; stand density; stand management; stem form; stems; summer; Synecology; Terrestrial ecosystems; tree crown; understory; uneven-aged stands; Romania; Carpathian region; Morphological plasticity; Forests; Abies alba; Growth; Picea ashies; Tolerance; Fagaceae; Leaf area; Multiaged stands; Stem; Selection systems; Regeneration; Abies; Mountain; Dicotyledones; Morphology; Angiospermae; Gymnospermae; Above ground plant part; Coniferales; Spermatophyta; Picea abies; Fagus sylvatica
• ISSN: 0931-1890; 1432-2285
• DOI: 10.1007/s00468-005-0026-2

Morphological plasticity was studied for advanced regeneration trees in different light environments of the mountainous, mixed-species forests in the Carpathian Mountains of Romania. The primary species in these mixtures were very shade tolerant silver fir (Abies alba Mill.) and European beech (Fagus sylvatica L.), and midtolerant Norway spruce (Picea abies (L.) Karst). Seedlings/saplings of these species were selected for measurements in different stands from two different geographical locations. Various morphological traits (specific leaf area, live crown ratio, crown width to length ratio, terminal to lateral ratio, number of internodal shoots, number of shoots in terminal whorl, stem symmetry, stem orientation, stem forking) for each regenerating tree were measured during summers of 2001 and 2002. Percentage of above canopy light and stand basal area measures were used to assess the available growing space for each seedling/sapling. Regression relationships were developed for the different morphological indicators as a function of these two variables. All species adapted their morphology along the gradient in light and basal area. Spruce seemed to be less adapted to low light conditions than both fir and beech. However, no significant differences in terms of shade tolerance were detected using the above indicators. In really dense stand conditions (less than 20% above canopy light and stand basal area above 36 m^sup 2^ ha^sup -1^), probability for stem forking in beech increased. In open, all three species adapted their morphology for vigorous growth. Under such conditions, spruce was better adapted than fir.[PUBLICATION ABSTRACT]