Entwicklung von Fichtenverjüngung im Lehrwald Sedrun der ETH Zürich (nördliche Zwischenalpen) | Development of Norway-Spruce Regeneration in the Training Forest of ETH Zurich in Sedrun, Canton of Grisons, Switzerland (Northern Intermediate Alps)
The development of planted Norway-spruce trees as well as the germination and self-seeding of natural regeneration were investigated on various forest locations on the north and south slopes between 1470 and 1800 m above sea level in the training forest of ETH Zurich in Sedrun, canton of Grisons, Switzerland.
IMPACT OF CLIMATIC AND LIGHT FACTORS ON THE GERMINATION AND SURVIVAL OF SILVER FIR ( ABIES ALBA MILL . ) AND NORWAY SPRUCE ( PICEA ABIES L . KARST . ) SEEDLINGS IN SELECTION FOREST
The paper presents results of seeding experiment of sliver fir (Abies alba Mill.) and Norway spruce (Picea abies L. Karst) in the selection forest. There is still a lack of knowledge about the germination and survival of seedlings in the differentiated forests. The experiment was performed in a managed forest with the selection structure. We established 24 sowing plots in the altitude 960−1050 m a.s.l., north exposure. One hundred of germinative seeds were sowed per one 1 m × 1 m plot. The level of direct and diffuse radiation and share of canopy gaps were measured on each of sowing plots. We analyzed the effect of applied tree species, different soil treatment, date of sowing and light environment on the abundance of germinated and survived seedlings. In addition, we studied the impact of climate conditions (average day temperatures and precipitations) on the seeds germination as well. The analysis revealed the direct effect of climate factors on the survival of spruce seedlings. We recorded the precipitation deficiency of 40 mm during the monitored 42 days that closely corresponded with the highest-recorded mortality of spruce seedlings (73 %). In time of the first inventory, the total amount of spruce seedlings was almost twenty-fold higher than the number of germinated firs. However, in time of the last inventory, the abundance of fir seedlings was 3.5 times higher than that of spruce seedlings. The different level of neither direct and diffuse radiation nor openness affected directly the average number of survived seedlings. Kľúčové slová: pokusný výsev, jedľa biela, smrek obyčajný, výberkový les
DEVELOPMENT OF WHITE SPRUCE AND ALPINE FIR SEEDLINGS ON CUT-OVER AREAS IN THE CENTRAL INTERIOR OF BRITISH COLUMBIA
Germination of white spruce and alpine fir was similar on mineral soil at all forest sites studied and averaged 33 per cent for spruce and 6 per cent for alpine fir.Mortality of seedlings in mineral soil was confined to the period of summer droughts. During this period maximum air temperatures approached 100° F., mineral soil exceeded 120° F. and humus 135° F. Water content of the upper 20 to 40 mm. of mineral soil was reduced below the wilting point and approximately 45 per cent of the seedlings died. The average root length of seedlings which died was 18 mm.; of those which survived, 37 mm. Greatest mortality occurred on fully exposed plots of dry habitats.On undisturbed seedbeds, germination of both species was very low. Seeds remained suspended and had insufficient contact with humic particles. Radicles of seeds which did germinate failed to reach compacted moist horizons. At the depth of root penetration, raw humus was at wilting point a few days after rain. A negligible number of seedlings of either...