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In 1990 the Federal State of Hesse (Germany) started a long-term faunistic research programme in selected Strict Forest Reserves. Here we report the results of the inventory of pseudoscorpions from seven reserves: Goldbachs- und Ziebachsrück, Hasenblick, Hohestein, Kinzigaue, Niddahänge east of Rudingshain, Schönbuche and Stirnberg. A total of 4567 specimens (315-1314 per site) belonging to 13 species (4-9 per site) were recorded using a broad spectrum of methods. The bulk of material comes from pitfall traps (83 %), followed by various types of stem eclectors (16 %). The structure and quality of the species assemblage in the oak-dominated flood plain forest of the Kinzigaue differs strongly from those of the remaining reserves, which are all dominated by beech. In the Kinzigaue a species-rich community (9 species) with balanced dominance structure (Shannon-Index 1.67) has been recorded. At this site, rare or moderately common species reach abundance proportions of more than 50 %. Most importantly, two species with strong affinities to pristine forests, Dendrochernes cyrneus and Chernes cimicoides, were exclusively recorded from this reserve. In contrast, the beech-dominated reserves were strongly dominated by a single species, Neobisium carcinoides (59-91 % of the specimens, Shannon-Index < 1), and the abundance proportion of the very common species exceeded 90 % in each of these areas. Temperature and altitude determine the composition of the species communities significantly. Of the recorded species, two will be categorized in the forthcoming Red Lists of pseudoscorpions of Germany and Hesse. Dendrochernes cyrneus (cat. 3 "vulnerable") reached an abundance proportion of 20 % in the reserve Kinzigaue. Dinocheirus panzeri (cat. G "indeterminate risk") has been recorded in single specimens from the reserves Hasenblick, Stirnberg and Niddahänge. The preferred habitat for most of the species is the forest. Species with strong affinities to forests make up more than 95 % of the specimens in all reserves except for Kinzigaue, where this proportion was 89 %. Species richness and abundances were not different between the Strict Forest Reserves (management was stopped at the end of the 1980’s) and the reference areas with continued forestry. However, the proportions of rare and moderately common species were higher in the Strict Reserves as compared to the reference areas.
In the Central German Uplands, Fagus sylvatica and Picea abies have been particularly affected by climate change. With the establishment of beech forests about 3000 years ago and pure spruce stands 500 years ago, they might be regarded as ‘neophytes’ in the Hessian forests. Palaeoecological investigations at wetland sites in the low mountain ranges and intramontane basins point to an asynchronous vegetation evolution in a comparatively small but heterogenous region. On the other hand, palynological data prove that sustainably managed woodlands with high proportions of Tilia have been persisting for several millennia, before the spread of beech took place as a result of a cooler and wetter climate and changes in land management. In view of increasingly warmer and drier conditions, Tilia cordata appears especially qualified to be an important silvicultural constituent of the future, not only due to its tolerance towards drought, but also its resistance to browsing, and the ability to reproduce vegetatively. Forest managers should be encouraged to actively promote the return to more stress-tolerant lime-dominated woodlands, similar to those that existed in the Subboreal chronozone.
Beginning in Belgium 1999, low mountain ranges of middle Europe were afflicted with the “European beech bark disease” (EBBD). It was first described by Hartig in 1878 as a complex disease where infestation of beech scale (Cryptococcus fagisuga; Hemiptera, Eriococcidae) is followed by fungal affection with Nectria coccinea and several white rot fungi. This often causes die back of mature beech trees, they tumble down and are colonised by woodbreeding beetles. Beside Belgium with 1 million cubic meter solid of beech wood (Fagus sylvatica); Luxembourg, France, and Southern Germany were affected in the last 6 years. In addition to known symptoms of EBBD, in all regions beech trees of an healthy appearance were surprisingly infested by the wood-breeding beetle Trypodendron domesticum. To understand mechanisms of this disease a chemo-ecological study was carried out, comparing the new phenomenon with the classical situation. A number of investigations of the involved beetles of the family of Scolytidae and Lymexylidae (BYERS 1992; KERCK 1976; KLIMETZEK 1984) suggest that the mechanisms of host-selection consist in the chemosensory differentiation of states of wood decay. The presence at the “border” between living and dying trees, T. domesticum turns out to be an interesting research object on xylobiont insects and physiological dying- and decaying-processes in trees. The underlying hypotheses of this work are: 1) Volatile organic compounds change successively during aging and decay of wood and characterise the most susceptible phase and breeding site for T. domesticum. 2) Volatiles released by trees afflicted by the new disease phenomenon are similar to volatiles of felled, susceptible deadwood
The map of “Regional natural forest composition by main tree species” (WALENTOWSKI et al. 2001) depicts Bavaria as a region largely predominated by the European beech (Fagus sylvatica). Analyses of climatope, hygrotope and trophotope of fir-dominated regional natural units make evident that the reasons for the preponderance of the European silver fir (Abies alba) are edaphic. In terms of regeneration vigour, growth and yield the fir particularly dominates in habitats with a combination of humus cover, acid-oligotrophic topsoils and clayey or waterlogged subsoils, where the beech usually exhibits stunted and malformed growth forms. This ecological preference has the effect that Bavarian Abies alba-forests are restricted to small patches within a matrix of potential natural vegetation formed by mixed deciduous-coniferous mountain forests. Within European Natura 2000 areas Abies- forests should be recorded carefully as special habitats. Their transitional character between temperate beech forests (habitat type 9130) and boreal spruce forests (habitat type 9410), the ecological preference of Abies alba as an endangered tree species and their sensitivity against environmental stressors, including changes in forest structure, air quality, and climate, make them important objects for nature conservation.