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
Study of External Parasites Infesting Carcharhinus Melanopterus Fish From The Red Sea In Jeddah, Saudi Arabia
Parasitic diseases are harmful and limiting factors in breeding and rearing ornamental fish industry, such as the Monogenea ( Dactylogyrus sp and Erpocotyletiburonis ) and copepod ( Pandarus sinuatus  and Anchistrotostangi ). The copepod and the monogenean are gill parasites found on the shark; CarcharhinusMelanopterus . The primary purpose of this study was to determine the parasitic infections of sharks in red sea in Jeddah. For this purpose, 19 female C. Melanopterus and 14 male C. Melanopterus were first examined for ectoparasites using wet mount under a light microscope. All male sharks had Monogenea and/or copepod in their gill and only 3 females haven’t infections. Then, we aimed to find a combination of copepod and monogenea infection in C. Melanopterus gills. 50% of male and 42% of female were infected by copepod and monogenea. Our findings revealed that the protozoan infections are very common among sharks. Although, no gross pathology was observed among infected shark, but it is likely that in case of any changes in the environment, then parasitic infections could be harmful.