Palaeoecology as a Tool for the Future Management of Forest Ecosystems in Hesse (Central Germany): Beech (Fagus sylvatica L.) versus Lime (Tilia cordata Mill.)

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.

2. Ancient reefs and islands

Reefs in deep geological time have been built by a succession of different kinds of life: plant, bacterial, and animal. Stromatolites and bryozoans were major reef-builders that persist today in minor or non-reef-building forms, sponges built entire reefs and are still important reef components, while several groups of major reef-builders flourished for a while and then became extinct: archaeocyathids which were similar to sponges, and coral-like forms including rugose and tabulate corals. Today’s reef-builders, cnidarian corals, appeared well after the great Permian-Triassic extinction event. All of these groups deposited vast quantities of limestone rock on which they live, often visible today as low mountain ranges. Reefs grow to the surface but not beyond, but upon them sand and sediments may build up, forming an island that attracts plants, then birds and other terrestrial forms of life. The sediments become cemented with the aid of rainwater too, and ‘low islands’ develop. Many islands also show their old, central volcanoes, resulting in the vast array of different combinations of coral island type. Today, however, there is a coral reef crisis due to overexploitation of a reef’s rich resources, from pollution of several kinds, and climate change.

Radar-based assessment of hail frequency in Europe

In this study we present a unique 10 year climatology of severe convective storm tracks for a large European area covering Germany, France, Belgium and Luxembourg. For the period 2005–2014, a high-resolution hail potential composite of 1×1 km2 is produced from two-dimensional radar reflectivity and lightning data. Individual hailstorm tracks as well as their physical properties, such as radar reflectivity along the tracks, were reconstructed for the entire time period using the Convective Cell Tracking Algorithm (CCTA2D). A sea-to-continent gradient in the number of hail days per year is found to be present over the whole domain. In addition, the highest number of severe storms is found on the leeward side of low mountain ranges such as the Massif Central in France and the Swabian Jura in southwest Germany. A latitude shift in the hail peak month is observed between the northern part of Germany, where hail occurs most frequently in August, and southern France, where the maximum amount of hail is 2 months earlier. The longest footprints with high reflectivity values occurred on 9 June 2014 and on 28 July 2013 with lengths reaching up to 500 km. Both events were associated with hailstones measuring up to 10 cm diameter, which caused damage in excess of EUR 2 billion.

Radar-based assessment of hail frequency in Europe

In this study we present a unique 10-year climatology of severe convective storm tracks for a larger European area covering Germany, France, Belgium and Luxembourg. For the period 2005–2014, a high-resolution hail potential composite of 1 by 1 km2 is produced from two-dimensional reflectivity radar data and lightning data. Individual hailstorm tracks as well as their physical properties, such as radar reflectivity along the tracks were reconstructed for the entire time period using the Convective Cell Tracking Algorithm (CCTA2D). A sea-to-continent gradient in the number of hail days is present over the whole domain. In addition, the highest number of severe storms is found on the leeward side of low mountain ranges such as near the Massif Central in France and the Swabian Jura in southwest Germany. A latitude shift in the hail peak month is observed between the northern part of Germany where hail occurs most frequently in August, and southern France where the maximum of hail occurs two months earlier. The spatially most extended footprints with high reflectivity values occurred on 9 June 2014 and on 28 July 2013 with lengths reaching several hundreds of kilometers. Both events implied hailstones measuring up to 10 cm which caused damage in excess of 2 Billions Euros.

Evapotranspiration at four sites representing land-use and height gradient in the Eastern Ore Mountains (Germany)

Less is known about evapotranspiration (ET) along elevation gradients of low mountain ranges, especially with regard to different land uses and concerning long-term studies. We investigate ET of four sites of different land-uses along an elevation gradient of a low mountain range over eleven years (2008–2018) based on daily values. Three different ET estimates are inspected, which can give a reasonable range of ET. These estimates are ET based on the energy balance residual (ET_residual), ET corrected for the energy balance closure gap (ET_corr) and ET not corrected for the energy balance closure gap (ET_uncorr). In general, ET_residual showed largest values and ET_uncorr showed lowest values with ET_corr in between. Average annual differences between ET_residual and ET_corr ranged between 111 mm a−1 and 196 mm a−1. Average annual differences between ET_uncorr and ET_corr ranged between 70 mm a−1 and 167 mm a−1. For two site years ET_corr was lower than ET_uncorr. This could be related to gap-filling. Differences between different estimates were site-specific and related to the respective energy balance closure gap. Principal component analysis revealed similar dependency on driving variables for all three estimates and all sites. Given the influence of the energy balance closure gap on ET_uncorr and ET_residual, we recommend using ET_corr, but ET_residual can be still useful especially for sites with low vegetation, which rarely experience water stress. Comparison of two coniferous sites situated at different altitudes showed frequently larger values for the site located at a higher altitude. This might be a result of rainfall interception, which however must be investigated at sub-daily timescale.

Der Rinderhandel im Hochstift Bamberg in der zweiten Hälfte des 18. Jahrhunderts

For the first time the study analyses comprehensively early modern cattle trade and points out the connection between economy and rule. The transfers provoked by environmental differences and seasonal cycles of usage were transacted particularly by jewish traders. Periodically lean oxes from the low mountain ranges were trated to the fertile valleys, where they were fattened and afterwards delivered into the cities with their growing consumption of meat. Farmers, butchers, traders and authorities struggled intensively for the organization of the trade. Demands for export restrictions got through only during price rise crisises. A discourse analysis proofs that authorities became more capable and willing of acting and how the discourse about trade policy began to be liberalized.

Neolithic settlement dynamics derived from archaeological data and colluvial deposits between the Baar region and the adjacent low mountain ranges, southwest Germany

The present study combines archaeological data with archaeopedological data from colluvial deposits to infer Neolithic settlement dynamics between the Baar region, the Black Forest and the Swabian Jura. A review of the state of archaeological research and an analysis of the processes leading to the discovery of the Neolithic sites and thereby the formation of the current archaeological site distribution in these landscapes is presented. The intensity of land use in the study area is compared with other landscapes in southern Germany using site frequencies. Phases of colluvial deposition are dated using AMS 14C ages of charcoals and luminescence ages of sediments and interpreted as local proxies for a human presence. Archaeological source criticism indicates that the distribution of the Neolithic sites is probably distorted by factors such as superimposition due to erosion and weathering effects limiting the preservation conditions for Neolithic pottery. A reconstruction of Neolithic settlement dynamics is achieved by complementing the archaeological data with phases of colluviation. Evidence for a continuous land use in the Baar region throughout the Neolithic is provided and sporadic phases of land use on the Swabian Jura and in the Black Forest are identified. In the late and final Neolithic, an intensification of colluvial formation can be noticed in the low mountain ranges.

Different forest cover and its impact on eco-hydrological traits, invertebrate fauna and biodiversity of spring habitats

Headwater springs in the German Low Mountain Ranges are local ecotone habitats and biogeographical islands embedded in and interlinked with their adjacent landscape. The structure of forests reflects the eco-hydrological conditions in substrate type occurrence, microhabitat richness and biodiversity in forest springs. This study considers effects from different forest land cover by comparing spring habitats in deciduous beech forests and coniferous spruce forests on eco-hydrological structures and biodiversity. Study areas include six different forest landscapes in the Low Mountain Ranges in Central Germany in Hesse and Thuringia. Hydro-morphological structure mapping and invertebrate sampling was executed within a multi-habitat sampling regime, which involves sampling plots being allocated according to the cover ratio of the occurring substrata. Aquatic and terrestrial spring zones are considered with respect to an ecotone approach. Some in situ measurements were implemented, such as pH values, to assess the acidity of the spring water. Results show obvious differences in acidity, substrate type cover ratios and biodiversity in deciduous and coniferous forest springs. Conifer forest springs were found tending to acidification while deciduous forest springs were slightly alkaline. Deciduous forest springs had higher cover ratios of organic microhabitats as well as a higher biodiversity in species richness and total number of individuals. Although it was not possible to clearly distinguish one direct key factor of fauna assemblages, negative effects from forest management practices (e.g. monoculture plantations of conifer forest) on spring habitats can be concluded.