RESUME

On the Causes of Excessive European Black Pine Dieback
Jaroslav Urban (pp. 502-503)

European black pine (Pinus nigra Arn.) belongs among one of the introduced species most often grown in forest and park cultures. Sudden worsening of their health, namely in young and medium aged plantings cultivated for decorative purposes, has been observed at many localities in the year 2000. The causes of decay and withering were investigated at 5 sites in Brno (230 m above sea level), Bystřička in Vsetín region (450 m a.s.l), and Deštné in Orlické Mts. (600 m a.s.l.). The primary cause of threat to plantings was an acute deficit in precipitation (a short-term drought) at the beginning of the vegetation season supported by high temperatures and drying winds. 

Also traditional way of growing hypersensitive plantings in nurseries in deep soils rich in nutrients fosters the increased sensitivity of pine to lack of humidity. Biotic harmful agents participated in the observed pine damage only little. Among pathogenic fungi observed in weakened trees species like Armillaria ostoyae (Romagn.) Herink, Lophodermium pinastri (Schrad.) Chev. and Mycosphaerella pini E. Rostr. were present, among bark insect pests species like Pityophthorus glabratus Eichh., Pityogenes bidentatus Hbst., P. quadridens Hart., P. bistridentatus Eichh., P. trepanatus Nördl., Cryphalus abietis Ratz., Magdalis rufa Germ., and Pissodes castaneus Deg.

Field performance of forest trees propagated in vitro by organ cultures and by somatic embryogenesis
Vladimír Chalupa (pp. 498-501)

Trees with desirable genetic traits can be rapidly produced by in vitro multiplication of superior genotypes that were obtained by selection, or by sexual crossing, or by recombinant DNA technology. In our experiments, fast in vitro propagation of many forest tree species was achieved using organ cultures and somatic embryogenesis (Chalupa 1974, 1983, 1985, 1987). Produced micropropagated trees were planted in the field and their field performance was observed 10-20 years. High field survival of micropropagated trees was achieved. After 12-18 years of growth in the field, the heigt and diameter dimensions of micropropagated trees were comparable to those of trees produced from seeds (graph 1, 2). Micropropagated trees regenerated from the same mother tree appeared to be identical to the mother plant. Obtained results indicate that in vitro regenerated trees were genetically uniform in comparison with the original genotypes. Growth of trees regenerated from somatic embryos was orthotropic and morphological abnormalities in the shape and form of needles, branches and stem were not observed. Trees of Picea abies and Larix decidua produced from somatic embryos reached considerable dimension at the age of 12 years that were comparable with the dimension of trees produced from seeds.

National parks from another point of view
Karel Kaňák (pp. 506-508)

The contemporary era is marked by extraordinary natural events such as volcanic or seismologic catastrophes etc. These disasters like many times in the geologic history of our planet, result in massive extinction of flora and fauna. In the past total extinctions used to be prevented by the existence of refuges, where small clusters of endangered species survived, oftentimes close to glacier edge. Humans, whose activities contribute substantially to the current ecological catastrophe, have a strong moral obligation to take part in the protective process. This idea has already been here. More than 7 thousands years ago, Noe’s Ark became the grandmother off all man-established refuges of all threatened animal and plant species. They are national parks which try to protect a purely natural regime without man’s intervention. General public both of our country and Bavaria has little understanding for this approach, because protectionistic solutions are generally regarded as extravagant whims of a certain social group. Unluckily, awkward naturalist’s propaganda contributes to society’s contempt. They are frequent public attacks at the size of the very existence of national parks and their large size. An excellent example is the area near Havířov in northern Moravia, where the undermined terrain interwoven by hundreds of shafts gradually caves in. Big craters have turn to lakes, little ones to pools and swamps. This large territory is inaccessible to public due to its rough character. The large size of the area and absence of man have triggered an accelerated of a new ecosystem. The bigger water bodies have attracted an unprecedently large heron community , whereas the pools and swamps have been settled by a variety of amphibians as yet unseen in these parts. The richness of birds, insect etc. life illustrates the way a refuge originates and functions in dependence on the sides of a Protected area. The ideal living conditions these species enjoy enhance their potential resistance to stress shock.