National Park Bavarian Forest

Grafenau, Germany

National Park Bavarian Forest

Grafenau, Germany
Time filter
Source Type

Tidiere M.,University of Lyon | Gaillard J.-M.,University of Lyon | Gaillard J.-M.,University of Zürich | Muller D.W.H.,University Claude Bernard Lyon 1 | And 5 more authors.
Experimental Gerontology | Year: 2014

Patterns of actuarial senescence vary among long-lived species. A proposed explanation of the evolution of species-specific senescence patterns is that increased levels of energy allocation to intra-male competition decrease the amount of energy available for somatic maintenance, leading to earlier or faster actuarial senescence. Previous studies did not provide support for such relationships, but did not focus on the intensity of allocation likely to shape inter-specific variation in actuarial senescence in males. Here, by analyzing data from 56 species of captive large herbivores, we tested whether actuarial senescence is more pronounced in species displaying a well-defined 'rut' period than in species with year-round reproduction. Using an original quantitative metric of the annual duration of reproductive activity, we demonstrated that the length of the mating season has no detectable effect on actuarial senescence. On the other hand, both diet and body mass are important factors shaping actuarial senescence patterns in male captive herbivores. © 2014 Elsevier Inc.

Muller J.,National Park Bavarian Forest | Butler R.,Swiss Federal Institute of forest | Butler R.,Ecole Polytechnique Federale de Lausanne
European Journal of Forest Research | Year: 2010

In contemporary forest management, also of commercial forests, threshold values are widely used for consideration of biodiversity conservation. Here, we present various aspects of dead-wood threshold values. We review published and unpublished dead-wood threshold data from European lowland beech-oak, mixed-montane, and boreo-alpine spruce-pine forests separately to provide managers of European forests with a baseline for management decisions for their specific forest type. Our review of dead-wood threshold data from European forests revealed 36 critical values with ranges of 10-80 m3 ha-1 for boreal and lowland forests and 10-150 m3 ha-1 for mixed-montane forests, with peak values at 20-30 m3 ha-1 for boreal coniferous forests, 30-40 m3 ha-1 for mixed-montane forests, and 30-50 m3 ha-1 for lowland oak-beech forests. We then expand the focus of dead-wood threshold analyses to community composition. We exemplify the two major statistical methods applied in ecological threshold analysis to stimulate forest researchers to analyze more of their own data with a focus on thresholds. Finally, we discuss further directions of dead-wood threshold analysis. We anticipate that further investigations of threshold values will provide a more comprehensive picture of critical ranges for dead wood, which is urgently needed for an ecological and sustainable forestry. © 2010 Springer-Verlag.

Aparicio A.,University of Marburg | Berens D.G.,University of Marburg | Muller J.,National Park Bavarian Forest | Farwig N.,University of Marburg
Acta Oecologica | Year: 2013

Geographic variation in the diversity, abundance or composition of plant and frugivore assemblages may have consequences for seed dispersal processes. Such variations may be related to climatic conditions as well as habitat characteristics such as fruit availability and forest complexity. Studying frugivore assemblages and seed dispersal processes along an elevational gradient can help to elucidate the interplay between the extent of dispersal services provided by frugivores and the geographic variability of the food resources. We studied frugivore assemblages on and fruit removal from 28 rowan trees (Sorbus aucuparia) along an elevational gradient in the Bavarian Forest, Germany. Both, the number of frugivore species and the number of frugivore individuals were significantly enhanced by high fruit availability. In both cases we found a slight interaction between elevation and fruit availability indicating a higher attractiveness of fruits for frugivores at lower than at higher elevations. A high number of frugivore individuals in turn significantly increased fruit removal from rowan trees. Here, we found a significant interaction between elevation and the number of frugivore individuals suggesting that the number of frugivores is of major importance for fruit removal particularly at lower elevations. Path analysis corroborated that the number of frugivore individuals indirectly mediated the effect of fruit availability on fruit removal. These findings suggest that fruit removal is rather influenced by changes in habitat characteristics than in climatic conditions across space. © 2013 Elsevier Masson SAS.

Lehnert L.W.,University of Marburg | Bassler C.,National Park Bavarian Forest | Brandl R.,University of Marburg | Burton P.J.,University of Northern British Columbia | And 2 more authors.
Journal for Nature Conservation | Year: 2013

Heavy natural disturbance in large protected areas of former commercial forests increasingly evokes European parliaments to call for management intervention because a loss of habitats and species is feared. In contrast, natural early successional habitats have recently been recognised as important for conservation. Current knowledge in this field mostly results from studies dealing only with selected taxa. Here we analyse the success of species across 24 lineages of three kingdoms in the Bavarian Forest National Park (Germany) after 15 years of a European spruce bark beetle (Ips typographus L.) outbreak that led to rapid canopy opening. Using indicator species analysis, we found 257 species with a significant preference for open forests and 149 species with a preference for closed forests, but only 82 species with a preference for the stand conditions transitional between open and closed forests. The large number of species with a preference for open forests across lineages supports the role of this bark beetle as a keystone species for a broad array of species. The slowdown of the outbreak after 15 years in the core zone of the national park resulted in less than half of the area being affected, due to variability in stand ages and tree species mixtures. Our case study is representative of the tree species composition and size of many large protected montane areas in Central European countries and illustrates that (1) natural disturbances increase biodiversity in formerly managed forests and (2) a montane protected area spanning 10,000. ha of low range mountains is likely sufficient to allow natural disturbances without a biased loss of closed-forest species. © 2012 Elsevier GmbH.

Angelstam P.,Swedish University of Agricultural Sciences | Roberge J.-M.,Swedish University of Agricultural Sciences | Axelsson R.,Swedish University of Agricultural Sciences | Elbakidze M.,Swedish University of Agricultural Sciences | And 12 more authors.
Ambio | Year: 2013

Assessing ecological sustainability involves monitoring of indicators and comparison of their states with performance targets that are deemed sustainable. First, a normative model was developed centered on evidence-based knowledge about (a) forest composition, structure, and function at multiple scales, and (b) performance targets derived by quantifying the habitat amount in naturally dynamic forests, and as required for presence of populations of specialized focal species. Second, we compared the Forest Stewardship Council (FSC) certification standards' ecological indicators from 1998 and 2010 in Sweden to the normative model using a Specific, Measurable, Accurate, Realistic, and Timebound (SMART) indicator approach. Indicator variables and targets for riparian and aquatic ecosystems were clearly under-represented compared to terrestrial ones. FSC's ecological indicators expanded over time from composition and structure towards function, and from finer to coarser spatial scales. However, SMART indicators were few. Moreover, they poorly reflected quantitative evidence-based knowledge, a consequence of the fact that forest certification mirrors the outcome of a complex social negotiation process. © 2013 The Author(s).

Muller J.,National Park Bavarian Forest | Muller J.,TU Munich | Bassler C.,National Park Bavarian Forest | Essbauer S.,University of Federal Defense Munich | And 5 more authors.
Journal of Biogeography | Year: 2014

Aim: We assessed the phenotypic responses of body size and organ weights of two small rodent species (Myodes glareolus and Apodemus flavicollis) to elevation, a surrogate for temperature and other environmental conditions. We expected not only an increase in body size (Bergmann's rule), but also an increase in relative heart weight with increasing elevation (Hesse's rule). Location: The Bohemian Forest, south-eastern Germany. Methods: We measured body length, body mass, and mass of the heart, lung, liver, kidneys and spleen of 386 adult specimens (188 of A flavicollis and 198 of M. glareolus) from 28 localities at 300-1450 m a.s.l., and also recorded the number of ectoparasites. We analysed body length using linear mixed models, with site as a random factor and species, sex, population density and elevation as fixed factors, and included all two-way interactions between species and the remaining fixed variables. For the organ masses, we included body length and body mass in the calculations to account for allometric variation of organ mass with body size. For a subset of individuals, we sequenced the mitochondrial D-loop to analyse genetic variation along the elevational gradient. Results: For both species, we found no support for Bergmann's rule. The body size of A. flavicollis even decreased with elevation. In contrast, the relative heart weight of both species significantly increased with elevation, thereby supporting Hesse's rule. Lung mass also increased with elevation. The mass of other internal organs showed no such consistent relationship with elevation. Neither species showed genetic differentiation across the elevational gradient. Main conclusions: Our results suggest that both rodent species respond to increasing elevation by decreasing overall energy expenditure and by increasing overall aerobic capacity. In the context of climate change, our results indicate that biogeographers should pay more attention to the potential significance of genetic and/or phenotypic plasticity of relative organ mass to environmental heterogeneity. © 2014 John Wiley & Sons Ltd.

Clauss M.,University of Zürich | Steuer P.,University of Bonn | Muller D.W.H.,National Park Bavarian Forest | Codron D.,University of Zürich | And 3 more authors.
PLoS ONE | Year: 2013

Digestive physiology has played a prominent role in explanations for terrestrial herbivore body size evolution and size-driven diversification and niche differentiation. This is based on the association of increasing body mass (BM) with diets of lower quality, and with putative mechanisms by which a higher BM could translate into a higher digestive efficiency. Such concepts, however, often do not match empirical data. Here, we review concepts and data on terrestrial herbivore BM, diet quality, digestive physiology and metabolism, and in doing so give examples for problems in using allometric analyses and extrapolations. A digestive advantage of larger BM is not corroborated by conceptual or empirical approaches. We suggest that explanatory models should shift from physiological to ecological scenarios based on the association of forage quality and biomass availability, and the association between BM and feeding selectivity. These associations mostly (but not exclusively) allow large herbivores to use low quality forage only, whereas they allow small herbivores the use of any forage they can physically manage. Examples of small herbivores able to subsist on lower quality diets are rare but exist. We speculate that this could be explained by evolutionary adaptations to the ecological opportunity of selective feeding in smaller animals, rather than by a physiologic or metabolic necessity linked to BM. For gigantic herbivores such as sauropod dinosaurs, other factors than digestive physiology appear more promising candidates to explain evolutionary drives towards extreme BM. © 2013 Clauss et al.

Loading National Park Bavarian Forest collaborators
Loading National Park Bavarian Forest collaborators