Emil Cienciala, Martin Černý (pp. 149 - 151)

The paper “Scenario analysis of wood production potential in the Czech Republic until 2050” discusses the key outputs of the project dealing with the model assessment of the country’s wood production under different management scenarios. The project was funded by the Ministry of Agriculture and run in accordance with the EU-funded project “SCEFORMA”.

At the EU level, the project involved the partner institutions from Hungary, Poland, Ukraine, the Netherlands (ALTERRA, project coordinator) and Finland (EFI, current EFISCEN model administrator and developer), while the Institute of Forest Ecosystem Research (IFER) acted as a scientific coordinator. The article shows the key results of the model runs for the Czech Republic. The project used the EFISCEN modeling tool that was adapted for the Czech-specific runs. The adaptation included a) a detailed set-up of a calibration dataset based on the Czech system of forest management units, b) the parameterization of growth rates using the Czech growth model SILVISIM (IFER) and c) the implementation of the management rules as recommended by the Czech Forestry Law. The model runs were prepared for three basic management scenarios, which were also combined with the expected effects of climate change on growth. The paper demonstrates that the modeling set-up permits defining and testing various management scenarios. Under current levels of harvesting the model predicts a further increase of growing stock, which would rise by approximately 30 % in 2050 as compared to that of 2000. Alternatively, more than 18 mill. mģ of timber could be harvested provided that the current growing stock (245 mģ) does not decrease. Even larger felling levels, about 20 mill. mģ, could be expected under the conditions of climate change. However, model projections also point to the problem of aging stands, a clear danger to stability of the Czech forests. It is concluded that the scenario modeling represents a unique predictive tool for providing vital information for strategic forestry planning.

František Soukup, Vítězslava Pešková, Jan Liška, Petr Kapitola (pp. 159 - 161)

Young larch trees drying-up and dieback in Czech forests occurs repeatedly at irregular overyear intervals and manifests by similar symptoms of damage. The article deals with possible causes of the phenomenon investigated by the research team during the last larch dieback period since 2001. The observation results are compared to knowledge gathered during the dieback in the nineties and also the results published by other authors during the 20th century. In case of the 2001s dieback, the decisive role is set down to biotic harmful factors, namely pathogenic fungi in connection with tree weakening by weather impact and insect sucking. Almost in all investigated samples from 13 localities pathogenic fungi potentially capable to participate in larch dieback were proved . Nectria sp. (anamorfa Fusarium subglutinans) was dominant, in some cases fungi of genus Valsa (anamorfa Cytospora), Phomopsis, Phoma and Lachnellula willkommii occurred. These fungi as casual parasites could manifest harmfully in connection with larch weakening by adverse course of weather in 2000 and partially in spring 2001. Other significant factor was represented by obviously strong attack of aphids of the family Adelgidae (- Sacchiphantes viridis, less Adelges laricis), as shown in the orientation observations of authors and forestry practices. The last year damage is estimated at several hundreds of hectares of reduced areas, stands affected the most were located in highland, submontane, and mountainous regions. Major protection possibilities that would mitigate larch dieback consist in silvicultural measures, in sanitation of strongly damaged individuals and in certain cases also in chemical control of aphids.