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Stav dřevinné vegetace na vybraných lavinových polích v Krkonoších
Strnádková, Simona
This thesis focuses on the current situation of woody plants on selected avalanche tracks in the Giant Mountains (Krkonoše), the Czech Republic, namely the avalanche tracks no. 2 (Žlab Úpičky), no. 3 (Úpská rokle) and no. 27 (Navorská jáma). Specific areas were delimited in these locations to measure biometric characteristics and potential damages of live trees, assess the occurrence and type of rejuvenation and evaluate the volume of dead wood. The measured data were summarised in graphical and tabular form, including maps with delimited areas. The processing of results also involved a comparison of both locations and evaluation of formulated hypotheses. We found out that 30-50 % specimens in the above locations are damaged. The most frequently damaged part included the trunk and the most frequent type of damage was trunk bending or breaking.
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Route belts as a organismus biotops
BABKA, Vladimír
Todays landscape is exposed to continually increasing human activities stress. The original biotopes are disturbed and fragmented from small to smaller segments. This fact can negatively influence the biodiversity. The railway line construction is a kind of such model, in this case its planed modernisation. This study deals with a railway embankment segment nr. 190 from Hluboká n. Vlt. to Zbudov. The aim of the work was to prove the railway line as an important and valuable biotope, which needs an enhanced attention. The vegetation biodiversity on four segments was studied. Totally 182 plant species were found with no rare species. The insect (beetles) species living in the wood of old trees were studied near the railway line. There were found 21 families with 52 beetle species where 3 species were rare. These important tree old stands were mapped too. The railway line history of this segment was processed too. The railway line creates a typical biotope with high vegetation biodiversity in this segment. The presence of the rare beetles living in the wood of old trees is more important.
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Communities of xylophagous insects in floodplain forest: distribution and host specificity
VODKA, Štěpán
During the last century the forests of Central Europe changed from open woodlands to even-aged stands with closed-canopy. This change resulted in severe decline of forest biodiversity. This study examines how, and why such change affected xylophagous insects. I have studied microhabitat preferences, i.e. distribution of xylophagous insects in canopy and understorey of closed forests, forest edges and wooded meadows. I used method of rearing insect from timber baits exposed to ovipositing females of xylophagous insects in different situations in the forest at the beginning if vegetation season. After one season of exposition,the baits were collected enclosed in fly-wire cages, where emerging insects were collected for two seasons. This thesis consists of two parts: The first part is an unpublished manuscript dealing with effect of habitat insolation, vertical stratification, forest structure and amount of dead wood on community of long-horned beetles (Cerambycidae) and jewell beetles (Buprestidae) feeding on wood of pedunculate oak (Quercus robur). Baits were exposed in the canopy and the understorey of forest interior, the canopy and the understorey of forest edge and on solitary trees on wooded meadows. Most insect species do prefer insoled wood for their development, and were more common in the understorey than in the canopy. Insolation of bait was thus the prime factor affecting composition of reared insects. No relation was found between dead wood volume and species composition or abundance of reared insects This shows that insolation of the dead wood is crucial to conservation of most xylophagous insects. The second part of the thesis studies effect of vertical stratification and insolation on distribution of xylophages feeding reared from wood of 8 tree species (Alnus glutinosa, Populus alba, P. x canadensis, Salix alba, Carpinus betulus, Quercus robur, Tilia cordata, Ulmus laevis) and host specificity of xylophages. Results show that: (i) community composition of xylophages reflects evolutionary history of their host plants; (ii) communities reared from different trees exhibit different preferences for forest strata and insolation of the habitat, probably in connection to preferred growth conditions of the host plant, (iii) many xylophagous insect species exhibit strong preferences to insoled habitats, and are thus confined to forest edges in extensively managed forests as well as in unmanaged forest reserves.
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