Bavarian Forests Research Articles

The Potential of Artificial Snags to Promote Endangered Saproxylic Beetle Species in Bavarian Forests

The creation of artificial snags, so-called high stumps, within forest management operations is a recently established tool to enrich standing deadwood as a habitat for saproxylic species. In this study, we analysed the impact of active high stump management on saproxylic beetle species. We selected 63 high stumps in six Bavarian forest districts (Germany), which were felled and subjected to close examination, focusing on beetle (Coleoptera) colonization. We identified 63 emerged coleopteran species belonging to 29 families; a further 10 taxa were identified only at the genus or family level, respectively. Moreover, 17% of the obtained taxa are listed in the German Red List of Coleoptera. Furthermore, 32% of the examined high stump trunks, predominantly broad-leaved tree species, harboured Red List beetle taxa. In particular, trembling aspen (Populus tremula) showed a disproportionately high number of Red List beetle species. The total species richness of beetles was independent of the height, diameter and decay stage of the snags. High stumps (snags) containing Red List beetle species tended to have higher amounts of deadwood in their surroundings, but the difference was not significant. According to the results of our study, actively creating high stumps proved to be a suitable method for creating habitats and serve as stepping-stones for endangered saproxylic species. Proactive high stump management during harvest can be a valuable component of deadwood management and biodiversity protection in forests.

Carabid beetles in a regional and a country-wide elevation gradient of Bavarian forests: differences and thoughts on the value of false time series approaches

We studied the effects of global warming and rising temperatures on the ground beetle fauna of Bavarian beech forests using the space for time approach (false time series), and did so in two projects, at two geographical scales: firstly, a Bavarian-wide gradient of 50 plots in beech forests, and second a regional gradient in the Bavarian Forest in the mountains in eastern Bavaria consisting of 48 plots, which was not restricted to beech forests but also included subalpine spruce forests. For purposes of validation, we used as a backdrop data from 413 additional plots all across Bavaria from a wide range of forest habitats. We found five species that would be favoured and six species that would be disadvantaged by rising temperatures in beech forests. For another five species the conditions within the gradient studied reach both their minimum and their maximum temperatures. As a consequence of increasing temperatures there will be winners and losers in these forests and the species composition of ground beetle communities will change. Approximately the same number of species is likely to profit as will be affected negatively. However, when considering the “global responsibility species” for Germany, the balance is negative. It is imporant to note that species may react differently in different habitats and at different regional scales. Some species migtht be more endangered in a local gradient than in a regional gradient, and vice versa, and examples are provided for this. Climate effects proven for a certain habitat must not be the same for other habitats even within the same region if these were not included in the study design. These limitations must be taken into consideration when applying the results of such studies and especially when generalizing them. The benefits of a true time series compared to the popular "false time serices" provided by an elevational gradient are also highlighted using some examples.

Transformation of organic phosphorus compounds during 1500 years of organic soil formation in Bavarian Alpine forests – A 31P NMR study

In Bavarian alpine forests, long-term input of organic matter from conifer species has built up thick organic surface layers, thus immobilized substantial soil organic phosphorus upon calcareous parent materials. The composition of these phosphorus stocks, however, remained unrevealed. Therefore, we analyzed organic phosphorus species in three so called Tangelhumus (Histosol according to World Reference Base) profiles with different radiocarbon ages using alkaline extraction followed by one-dimension and two-dimension 31P nuclear magnetic spectroscopy in order to understand changes in organic phosphorus composition with soil organic matter genesis. A diverse phosphorus pool composed of monoesters, diesters, and phosphonates was detected. However, in these Tangelhumus soils only monoesters accumulated overtime and eventually dominated the organic phosphorus pool after 1558 years. Diesters and phosphonates did not show any significant accumulation pattern. The origin of monoesters varied with soil depth and soil age: monoesters in young surface soils were actually hydrolysis products of diesters released by plant and microbial cells during alkaline extraction; whereas in older soils monoesters originated largely from Ca-bound precipitates formed after long-term in situ decomposition of organic matter and stabilization by Ca2+. Myo-inositol hexakisphosphate was below detection limit in all soils. The presence of its scyllo and other isomers likely pointed to direct synthesis by microorganisms instead of microbial epimerization from myo-inositol hexakisphosphate. In general, the overall picture of phosphorus speciation manifested as the continuous degradation of organic matter and accumulation of monoesters. Therefore, the current data indicated no involvement of humification process but favored the soil continuum model.

Phylogenetic analysis of Puumala virus strains from Central Europe highlights the need for a full-genome perspective on hantavirus evolution.

Puumala virus (PUUV), carried by bank voles (Myodes glareolus), is the medically most important hantavirus in Central and Western Europe. In this study, a total of 523 bank voles (408 from Germany, 72 from Slovakia, and 43 from Czech Republic) collected between the years 2007-2012 were analyzed for the presence of hantavirus RNA. Partial PUUV genome segment sequences were obtained from 51 voles. Phylogenetic analyses of all three genome segments showed that the newfound strains cluster with other Central and Western European PUUV strains. The new sequences from Šumava (Bohemian Forest), Czech Republic, are most closely related to the strains from the neighboring Bavarian Forest, a known hantavirus disease outbreak region. Interestingly, the Slovak strains clustered with the sequences from Bohemian and Bavarian Forests only in the M but not S segment analyses. This well-supported topological incongruence suggests a segment reassortment event or, as we analyzed only partial sequences, homologous recombination. Our data highlight the necessity of sequencing all three hantavirus genome segments and of a broader bank vole screening not only in recognized endemic foci but also in regions with no reported human hantavirus disease cases.

A new way of carbon accounting emphasises the crucial role of sustainable timber use for successful carbon mitigation strategies

The roles of forest management and the use of timber for energy in the global carbon cycle are discussed. Recent studies assert that past forest management has been accelerating climate change, for example in Europe. In addition, the increasing tendency to burn timber is an international concern. Here, we show a new way of carbon accounting considering the use of timber as a carbon neutral transfer into a pool of products. This approach underlines the robust, positive carbon mitigation effects of sustainable timber harvesting. Applying this new perspective, sustainable timber use can be interpreted not as a removal but a prevention of carbon being converted within the cycle of growth and respiration. Identifying timber use as a prevention rather than a removal leads to the understanding of timber use as being no source of carbon emissions of forests but as a carbon neutral transfer to the product pool. Subsequently, used timber will then contribute to carbon emissions from the pool of forest products in the future. Therefore, timber use contributes to carbon mitigation by providing a substantial delay of emissions. In a second step, the carbon model is applied to results of a previous study in which different timber price scenarios were used to predict timber harvests in Bavarian forests (Germany). Thus, the influence of the economic dimension “timber price” on the ecological dimension carbon sequestration was derived. It also shows that these effects are stable, even if an increasing tendency of burning timber products for producing energy is simulated. Linking an economic optimization to a biophysical model for carbon mitigation shows how the impact of management decisions on the environment can be derived. Overall, a sustainably managed system of forests and forest products contributes to carbon mitigation in a positive, stable way, even if the prices for (energy) wood rise substantially.

Modelling the effects of global warming on the ground beetle (Coleoptera: Carabidae) fauna of beech forests in Bavaria, Germany

We studied the effects of warming and rising temperatures on the ground beetle fauna of Bavarian beech forests using the space for time approach at two geographical scales. The first was a Bavarian-wide gradient of 50 plots in beech forests and the second a regional gradient in the Bavarian Forest in the mountains in eastern Bavaria consisting of 48 plots, which also included subalpine spruce forests. For purposes of validation, we used backdrop data from 413 additional plots all across Bavaria from a wide range of forest habitats. We found five that would be favoured and six that would be disadvantaged by rising tem- peratures in beech forests. For another five the conditions within the gradient studied reach both their minimum and their maximum temperatures. As a consequence of increasing temperatures there will be winners and losers in these forests and the spe- cies composition of ground beetle communities will change. Approximately the same number of is likely to profit as will be affected negatively. However, when considering the global responsibility species for Germany, the balance is negative. Species may react differently in different habitats and at different regional scales, which must be taken into consideration when applying the results.

UN APERÇU DE LA FILIÈRE FORÊT-BOIS EN BAVIÈRE

Bavaria is the largest of the German landers and also the most heavily forested. A team from the French Ministry of Agriculture, Agri-food and Forestry went on a two-day assignment that allowed information about public and private management of French and Bavarian forests to be exchanged. There were also exchanges on the forestry and forest-based industry of both entities. A large number of subjects were broached (hunting, climate change, management of public and private forests, restructuring of the industry). It became apparent that the forestry and forest-based industry on both sides have similar or complementary structures and approaches. Furthermore, the benefits of working jointly on a European scale were emphasised, in particular in the area of standards for timber. Cooperation between the forest and forestry-based cluster in Bavaria and their counterparts in France would be beneficial to both parties

Three-dimensional partitioning of diversity informs state-wide strategies for the conservation of saproxylic beetles

Global conventions on biological diversity force governments to develop region-wide conservation strategies. Such strategies are difficult to design for all taxa because little is known about the important spatial scales. Here we applied additive partitioning of the diversity of saproxylic beetles in Bavarian forests in Southern Germany using a nested hierarchical design of five increasingly broader spatial levels: trap, strata, forest stand, forest site, and ecoregion. We consistently found a significantly higher percentage than expected by chance of between ecoregion diversity and significantly lower α diversity within traps. A significant proportion of β diversity was also found between stands. Analysis of species represented by <0.005% of all specimens in our samples and of species classified as threatened revealed similar results. Critical spatial scales for threatened species encompassed the critical levels of common species. Within habitat substratum guilds, the proportion of β diversity increased from species associated with fresh wood to those associated with rotten wood to those associated with fungi. Our results suggest that the most effective way to ensure saproxylic beetle diversity in a state-wide strategy is to add new conservation sites within different ecoregions and to establish new conservation areas in additional forest stands, rather than to enlarge reserves. Our findings further suggest that monitoring of saproxylic beetle diversity on a broader scale in European temperate forests can be restricted to “monitoring species”, i.e. a subgroup of families easy to identify, and that canopy sampling can be neglected without a substantial loss of information.

Management of Chamois in Bavaria (Germany): The Importance of Game Activities in Scabies Control.

In Bavaria (Germany), scabies was registered for the first time in the year 1824 among the chamois population of the Berchtesgaden region, and disappeared 6 years later. For the next 119 years, the chamois populations in the Bavarian Alps seemed not to be infected by scabies. But in 1949 scabies occurred again in the Bavarian chamois populations east of the River Inn, with origin in the Berchtesgaden region. Scabies has been recorded repeatedly since then. Whereas between 1949 and the early 1990s scabies had a great impact on the development of the chamois populations in the Bavarian Alps east of the river Inn, the disease has had little significance since 1995. As it is assumed that there is a link between high population density and the occurrence of scabies among chamois, hunting bags (as indicators of population density) were compared with the recorded scabies cases (shot or deceased game) among chamois populations in the Bavarian state forests east of the river Inn. Data collected from the Berchtesgaden Forest Office were further analysed according to age and sex parameters. There is a highly significant, inverse, non-parametric correlation between recorded incidences of scabies and hunting bags in the whole study area and in the area of Berchtesgaden Forest Office. The results of the analysis show that bucks were slightly more likely to be registered with scabies than does (p=0.018). Young animals (yearlings and juveniles) played only a secondary role in terms of scabies prevalence. Both the historical background of scabies in the Alps and the present study support the above-mentioned hypothesis that the incidence of scabies in chamois is related to high chamois population densities. The spread of scabies can therefore be slowed down or prevented by increasing game bags over a large area.

Are Bavarian Forests (southern Germany) at risk from ground-level ozone? Assessment using exposure and flux based ozone indices

Exposure and flux-based indices of O 3 risk were compared, at 19 forest locations across Bavaria in southern Germany from 2002 to 2005; leaf symptoms on mature beech trees found at these locations were also examined for O 3 injury. O 3 flux modelling was performed using continuously recorded O 3 concentrations in combination with meteorological and soil moisture data collected from Level II forest sites. O 3 measurements at nearby rural open-field sites proved appropriate as surrogates in cases where O 3 data were lacking at forest sites (with altitude-dependent average differences of about 10% between O 3 concentrations). Operational thresholds of biomass loss for both O 3 indices were exceeded at the majority of the forest locations, suggesting similar risk under long-term average climate conditions. However, exposure-based indices estimated higher O 3 risk during dry years as compared to the flux-based approach. In comparison, minor O 3-like leaf injury symptoms were detected only at a few of the forest sites investigated. Relationships between flux-based risk thresholds and tree response need to be established for mature forest stands for validation of predicted growth reductions under the prevailing O 3 regimes.

Extraordinary snow accumulations over parts of central Europe during the winter of 2005/06 and weather‐related hazards

During the winter of 2005/06, record-breaking snow accumulations were observed in many locations in south-east Germany, large parts of Austria and in the low mountain ranges along the Czech/German as well as Czech/Austrian borders. In the lowlands, low mountain ranges and eastern Alpine valleys of the above-mentioned study area, the snow mantle reached its maximum depth in early to mid-March, with many stations reporting snow depths between 40 and 60 cm in the morning hours of 7 March 2006 (Figure 1), with a few readings of more than 100 cm, e.g. Lunz am See 139 cm (Eastern Alps, Austria, altitude of 615 m above sea-level (a.s.l.)) and Zinnwald-Georgenfeld 150 cm (Erz Mountains, Germany, 882 m a.s.l.). Shortly after this date, widespread snow depths of more than 100 cm were also observed in the Bavarian and Bohemian Forests and the Austrian Forest Quarter. The picture taken at Neureichenau (Bohemian Forest, Germany) on 12 March 2006 gives a good impression of the landscape buried under the deep snow (Figure 2). As seen in the picture, local residents had to remove the snow from the roofs of their houses to avoid collapse. The winter of 2005/06 was not only notable in terms of the snow depth at the end of the winter season, but also in terms of snow-cover duration and intermittent heavy snowfall events in the low-lying areas of the study region. Among the most momentous weather-related hazards were the collapse of several roofs under the heavy weight of the snow. For example, the breakdown of the dome of an ice skating hall at Bad Reichenhall (Germany) on 2 January killed 15 people and injured over 50. As many winters in the last two decades were unusually mild and, consequently, marked by a poor snow cover, the winter of 2005/06 was perceived by the local residents as being extremely snowy, cold and long. People will commemorate the winter of 2005/06 as being the severest in decades; at some locations the severest within living memory. In the present contribution, we will highlight that from the climatological standpoint the winter was neither unusually wet nor cold, but characterised by the absence of significant thawing episodes. We will relate this to the anomalous frequency and persistence of two particular circulation weather types. This article will also give a more detailed account of the weatherrelated hazards and will briefly discuss if this type of extreme weather is likely to be expected more frequently in the future. For these aspects, the winter period is defined as the time from the beginning of October to the end of March. The winter of 2005/06

Foraging activity of central European Myotis myotis in a landscape dominated by spruce monocultures

In Bavarian forests dominated by spruce monocultures, radio-tracked Myotis myotis did not select stands of deciduous forests but used them according to their availability. The bats preferred tall single strata forests with little undergrowth. Twenty-six per cent of the foraging time was spent outside forests in meadows and fields. An explanation for the existing relationship in Bavaria between population density of the ground-gleaning M. myotis and the extent of deciduous forests appears to be the higher percentage of open floor suitable for foraging in old beech forests and beech-mixed forests compared to old stands of spruce. A major recommendation from our study is that in order to preserve the density of M. myotis in Bavaria, habitat management (use of beech in forestry, reintroduction of cattle grazing in forests) is necessary to compensate for an expected decrease in foraging area quality in spruce-dominated forests.

Comparative studies on the fine root status of healthy and declining spruce and beech trees in the Bavarian Alps and occurrence of Phytophthora and Pythium species

Investigations on root and crown status of spruce and beech were carried out on selected trees in the ‘Werdenfelser Land’ area (Bavarian Alps, Southern Germany). In addition, the association of fine root pathogens of the genera Phytophthora and Pythium with the trees’ rhizosphere was studied. In a variety of stands representing various site conditions, soil and root samples were taken from 12 spruce (Picea abies) pairs and eight beech (Fagus sylvatica) pairs. Each pair consisted of a healthy and a declining tree as indicated by crown transparency. The root status was characterized using a set of parameters, and correlations between crown and fine root status were observed. In spruce, most parameters decreased significantly with increasing crown transparency, whereas in beech, correlations were less pronounced. The total number of lateral roots per cm small root (diameter 2–5 mm) was significantly lower in both species for declining trees compared to healthy trees. Pythium spp. were isolated from 15 of 24 soil samples taken from under spruce, and from eight of 16 samples from under beech. Phytophthora citricola was found in two beech stands only. Among the isolated species, Pythium anandrum, Pythium inflatum and Pythium acrogynum were identified according to morphological features. After polymerase chain reaction‐restriction fragment length polymorphism analysis, residual Pythium isolates were assigned to four different groups. No crown transparency‐dependent differences in isolation frequency were found. In soil infestation tests, all species tested caused root damage on both young spruce and beech plants, with P. citricola being the most aggressive pathogen. Additionally, Pythium‐infected beeches showed severe leaf chloroses and necroses. Due to their low isolation frequency, Phytophthora spp. are not considered to play a major role in the decline of spruce and beech in the investigated area. Pythium spp., however, were isolated frequently, showed pathogenicity towards the fine roots of spruce and beech, and are therefore considered to be at least contributing factors in the decline of Bavarian mountain forests.

Untersuchungen zur spät- und postglazialen Vegetationsgeschichte im nordöstlichen Bayern (Bayerisches Vogtland, Fichtelgebirge, Steinwald)

Palynological investigations in northeastern Bavaria (Bavarian Vogtland, Fichtelgebirge, Steinwald) reveal the Late Glacial and Postglacial history of the regional vegetation. Radiocarbon data in comparison with those from the neighbouring regions (Rhön, Oberpfälzer Wald, Bavarian Forests) show a time lag in the development of the arboreal vegetation due to migration processes. The Fichtelgebirge is the southernmost part of northeastern Bavaria where the early Alleröd period (pollen zone IIa) is characterised by a dominance of birch forests. Hazel reached maximal values around 8000 BP in the area from the Fichtelgebirge to the Bavarian Forests, e.g. about 600 years earlier than in the more northern Rhön mountains. For spruce there is a considerable time lag between the Bavarian Forests and the Fichtelgebirge. Spruce spreading started in the Fichtelgebirge during the older part of the Atlantic period (pollen zone VI). At the same time, spruce already was the dominant tree in the Bavarian Forests. During the younger part of the Atlantic period (pollen zone VII) spruce and mixed oak forest tree species frequently occurred in the Fichtelgebirge. At the end of pollen zone VI, spruce came to dominance. At the same time, the immigration of beech started. During the Subboreal period (pollen zone VIII), spruce remained being a dominant member in the forests and at the end of pollen zone VIII, fir began to spread rapidly. During the first part of the Subatlantic period (pollen zone IX) spruce, beech, fir and pine formed the mountainous forests in the Fichtelgebirge. In the area of the Bavarian Vogtland, however, fir was a dominant forest tree during pollen zone IX, while spruce and beech played a less important role. During the 12th century, human colonisation started in the area of the Fichtelgebirge. This is 400 years later as in the area of the Rhön mountains. Indicators for earlier forest clearances are rare or absent.

Mycophagy and spore dispersal by small mammals in bavarian forests

Spores of hypogeous fungi found in stomach contents of mice and voles trapped in high and low-elevation forests were identified and recorded with estimates of frequency of fungal genera. The data show differences between sites in the number of fungal taxa consumed. A similar taxa frequency was noted on plots with regenerations adjacent to mature stands. Spores of Endogonaceae were found to occur more often within reforestation sites linked with qualitative changes in ground vegetation.

Zur Verwendung von Tabakpflanzen als Bioindikatoren waldschädlicher, photochemischer Immissionen

In two Bavarian forests close to oil industries certain tobacco cultivars were exposed between May and October 1973 in order to test and proof photochemical air pollution. Especially in one of the both areas distinct damage markings on the leaves were visible, in agreement to those described by literature as typical symptoms of smog damage. The intensity of damages was not only different between the cultivars, but also especially significant higher on the plants exposed in the neighbourhood of industry than on those exposed in a more distant area. On the other hand it cannot be excluded, that the pattern of damage was a symptom of virus infection supported by the influence of air pollution. It is referred to the problematic use of tobacco plants as biologic indicators of air pollution, and in this connection it is further mentioned the great importance of our indigenous conifersPicea abies andPinus silvestris. For completion and better interpretation the experiment shall be repeated in summer 1974.

Über die Verbreitung und Dichte einiger Bodenmilben (Acari, Acapiformes) in zwei bayerischen Nadelholzwäldern

Studies on distribution and abundance of some Acariformes mites in two coniferous Bavarian forests

A Comparative Ecological Analysis of the Soil Mesostigmata (Acarina) Associated with some Coniferous Bavarian Forests

AbstractThe present study describes an 12‐month census made from 2 Bavarian coniferous forest environments. The seasonal population fluctuations of the mesostigmatid fauna were found at various intervals. Comparisons were made throughout of the ecology of species in both sites of study, together with the relationship between densities and soil ecological factors, viz. temperature and rainfall.The 2 sampling sites generally had a similar species spectrum for Mesostigmata. Fourteen species were identified and grouped into 12 families.The total number of Mesostigmata was rather high in Grafrath compared with Siegenburg. The populations fluctuated with time and marked differences occurred in the patterns of variation shown by different species. There was significant evidence that the changes as a whole bore strong relationships to the fluctuations of soil temperature and precipitation. Possible explanations for summer and winter peak mite populations were discussed.ZusammenfassungUntersuchungen über die Mesostigmata‐(Acarina‐) Faunen einiger bayerischer Nadelwaldböden12monatige vergleichende Studien zeigten, daß die Fluktuation der Populationen von Mesostigmata‐Arten und ‐Gruppen in unterschiedlichen Intervallen verlief. Die zwei miteinander verglichenen Hauptstandorte, Grafrath und Siegenburg, wiesen ähnliche Artenspektren auf. Insgesamt wurden 14 Arten festgestellt, die 12 Familien angehörten. Es zeigte sich eine signifikante Beziehung zwischen Dichteveränderungen der Milben sowie Temperatur und Niederschlagshöhe. Mögliche Erklärungen für die Entstehung sommerlicher und winterlicher Dichte‐Maxima werden erörtert.