Central European Highlands Research Articles

The vertical form of the common ivy Hedera helix L. is associated with diverse and semi-natural forests in Central European highlands

Understanding the role of epiphytic vegetation and other microhabitats created by plants (hereafter lianas) developing on the surrounding ones is crucial for understanding the functioning of forest communities. Despite the observed increase in the biomass of lianas, the factors connected with forest plant communities determining their occurrence have not been investigated in a temperate zone. This research concerns the determinants of vertical form of the common ivy Hedera helix L. occurrence in highland forests in Central Europe. We established 69 pairs of sites, which consisted of areas inhabited by the vertical form of ivy and control areas (hereafter non-ivy plots). The sites with ivy were characterized by a higher volume (488 m3 ha-1 ± 251 SD vs. 411 m3 ha-1 ± 186 SD), a higher amount of deadwood (34 m3 ha-1 ± 39 SD vs. 23 m3 ha-1 ± 29 SD), and a higher tree species richness (8.0 species/ha ± 2.2 SD vs. 6.8 species/ha ± 2.14 SD) than non-ivy plots. The presence of vertical form of ivy was mainly influenced by a large share of alder in the stand and a higher diversity of trees and shrubs. Moreover, the number of large ivy vines increased with the presence of veteran trees. The presence of gaps was not conducive to the occurrence of large vines. The northern exposure and the presence of deadwood had a positive effect on the number of vines per tree. Our results contribute to the knowledge about variables influencing the occurrence and development of ivy vertical form in forests. The obtained results indicate that ivy requires diverse forests with a mix of trees and numerous veteran ones, which makes this species a good candidate as an indicator of forest habitat quality. We suggest that the common ivy should be protected within its native range and forest patches containing dense ivy vines should be excluded from silviculture.

Detrital zircon U–Pb age analysis of last glacial loess sources and proglacial sediment dynamics in the Northern European Plain

Loess deposits along the northern fringe of the European loess belt potentially record past changes in dust emission from areas proximal to former ice sheets. Recent chronologies from loess deposits across this region generally agree on greatly enhanced dust deposition rates when the Fennoscandian Ice Sheet reached its maximum extent during the late last glacial. However, uncertainties over the material's source and origin limit understanding of the causes of this enhanced dust activity. In particular, loess in southwestern Poland has been attributed to multiple origins, mainly involving glaciofluvial outwash plains along the Fennoscandian Ice Sheet margin and/or local sources in the mountainous areas of the Sudetes and Western Carpathians. Here we apply detrital zircon U–Pb age analyses for a large number of grains recovered from four loess samples taken from different stratigraphic units exposed at Biały Kościół in southwestern Poland, previously luminescence dated to MIS 4–2, to assess loess provenance as well as its temporal evolution during last glacial Fennoscandian Ice Sheet fluctuations. Furthermore, we analysed the detrital zircon U–Pb age spectra of five samples from potential source sediments to constrain the history of sediment recycling and mixing within the Northern European Plain prior to deflation and loess deposition. The broad range of zircon age components detected in the four loess samples suggests both Fennoscandian and closer Peri-Gondwanan proto-sources while a narrow, dominant Carboniferous age peak is consistent with sourcing from the local Strzelin Hills in the Sudetic foreland. However, the presence of both Fennoscandian and Peri-Gondwanan derived grains in samples from potential source sediments reveals that this mixture of sediment sources is widespread across the Northern European Plain, as a result of long-term glacial and fluvial reworking of cover sediments in the proglacial area throughout the Quaternary. Local rivers draining the Sudetic foreland transported this Fennoscandian-Peri-Gondwanan sediment mixture along with particles denuded from the Strzelin Hills, resulting in a nearby, temporally stable dust source for the Biały Kościół loess during MIS 4–2, while dust emission rates were substantially increased during the last glacial maximum. Given that our model for loess formation at Biały Kościół essentially involves sediment distribution via rivers prior to short distance aeolian transport, we infer that the proportion of northern ice sheet derived particles in European loess deposits is mainly controlled by the drainage pattern of major rivers in relation to Pleistocene ice margins where glaciofluvial sediment is abundant. Based on the presence of Fennoscandian derived zircon grains in European loess deposits, we constrain a southern limit of the influence of northern ice sheet dust sources along the central European highlands that currently divide drainage between the Northern European Plain and the Danube Basins.

Effect of Soil Diversity on Forest Plant Species Abundance: A Case Study from Central-European Highlands

Plant distribution is most closely associated with the abiotic environment. The abiotic environment affects plant species’ abundancy unevenly. The asymmetry is further deviated by human interventions. Contrarily, soil properties preserve environmental influences from the anthropogenic perturbations. The study examined the supra-regional similarities of soil effects on plant species’ abundance in temperate forests to determine: (i) spatial relationships between soil property and forest-plant diversity among geographical regions; (ii) whether the spatial dependencies among compared forest-diversity components are influenced by natural forest representation. The spatial dependence was assessed using geographically weighted regression (GWR) of soil properties and plant species abundance from forest stands among 91 biogeographical regions in the Czech Republic (Central Europe). Regional soil properties and plant species abundance were acquired from 7550 national forest inventory plots positioned in a 4 × 4 km grid. The effect of natural forests was assessed using linear regression between the sums of squared GWR residues and protected forest distribution in the regions. Total diversity of forest plants is significantly dependent on soil-group representation. The soil-group effect is more significant than that of bedrock bodies, most of all in biogeographical regions with protected forest representation >50%. Effects of soil chemical properties were not affected by protected forest distribution. Spatial dependency analysis separated biogeographical regions of optimal forest plant diversity from those where inadequate forest-ecosystem diversity should be increased alongside soil diversity.

Sphagnum establishment in alkaline fens: Importance of weather and water chemistry.

Sphagnum expansion to alkaline fens has accelerated during the last decades in Europe, leading to changes in diversity, habitat distributions and carbon storage. The causes are still not clearly understood and involve an interplay between climate change, hydrology, nutrient supply and Sphagnum physiology. We conducted a 4-year field experiment in eight fens in Central European highlands and assessed survival and establishment of individual apical shoot fragments of S. flexuosum, S. warnstorfii and S. squarrosum transplanted along the microtopographical gradient. In a laboratory experiment, we tested combined effects of desiccation and high calcium bicarbonate concentration on Sphagnum survival. We found that in unflooded positions, living shoots of Sphagnum and brown mosses lowered [Ca2+] and pH in their capillary water, in contrast to dead fragments; yet without differences between species. Survival and expansion of Sphagnum fragments, which did not die of acute calcium toxicity during first weeks/months, was negatively affected by dry weather and alkaline water chemistry, reflecting Sphagnum intolerance to desiccation and to combined high [Ca2+] and pH. Shoot fragments expanded to patches only when precipitation was high. Interestingly, non-toxic concentration of calcium bicarbonate reduced desiccation damage in Sphagnum, probably through protection of membranes or other cell components. This mechanism would facilitate Sphagnum survival in elevated, frequently desiccated microhabitats of calcareous fens such as brown-moss hummocks. However, since water-retaining capacity of few Sphagnum shoots is insufficient to change water chemistry in its surroundings, surface acidification may occur only once the environment (e.g. sufficient humidity) enabled expansion to larger mats. Then, the retained rainwater together with hardly decomposable Sphagnum litter would separate mire surface from groundwater, speeding up successional shift towards poor fens. Sphagnum expansion to alkaline fens is therefore more likely in humid regions.

Fluctuations in the properties of forest soils in the Central European highlands (Czech Republic)

Fluctuations in forest soil properties were described using a time series analysis of the clay content, the chemical (CaO, MgO, C<sub>org</sub>, and N<sub>tot</sub>) and physicochemical (pH and base saturation (BS)) soil parameters from 1953 to 2008. The analysis involved the dominant acidic, nutrient-rich, and waterlogged forest ecosystems on the territory of the Bohemian Massif and the Outer Western Carpathians (Czech Republic). Trends in the development of the time series of soil properties were optimized by Gauss-Newton’s transformation of the exponential combination of the cyclometric function and Euler’s number. Identical functions of regression equations on the fluctuations of nutrients, pH, BS, and C<sub>org</sub> indicated parallel trends of soil development in different forest ecosystems. Equations representing identical, predictable patterns in C<sub>org</sub> fluctuation indicated the stability of the trend. Differences in temporal patterns of nutrients, pH, and BS in different forest ecosystems indicated the susceptibility of developmental trends to external factors. Different regression equations of fluctuations of soil clay and N<sub>tot</sub> indicated the occurrence of permanent differences during the soil development. During the period of 1953–2008, soil pH, BS, and CaO concentration decreased but the content of C<sub>org</sub> and N<sub>tot</sub> increased. Regression functions indicate that pH and BS of forest soils in the Czech Republic have temporarily increased and the content of C<sub>org</sub> and N<sub>tot</sub> have decreased during the period 2009–2014. Continuous increase in BS is only sustainable if concurrent with an increase in C<sub>org</sub>.

The larva of Oecetistripunctata (Fabricius, 1793) (Trichoptera, Leptoceridae).

Oecetis tripunctata is a widely distributed leptocerid in Europe, ranging from the Iberian and Apennine peninsulas and the Central and Western European highlands to the plains of Eastern Europe. The long, single-bladed mandibles are indicative for a predacious lifestyle. This paper describes the previously unknown larva of Oecetis tripunctata. Information on the morphology of the 5th larval instar is given, and the most important diagnostic features are illustrated. A synoptic key for the European species of Oecetis is also provided. In the context of existing identification keys the larva of Oecetis tripunctata keys together with Oecetis intima and Oecetis notata. Oecetis tripunctata is separated from the other two species by the fact that a double row of long setal fringes is lacking at the hind tibiae and that several long setae are present on the protrochantinus.

The larvae of Stenophylax mitis McLachlan 1875 and Allogamus hilaris (McLachlan 1876a) (Trichoptera: Limnephilidae), with notes on ecology and zoogeography

The paper gives a description of the hitherto unknown larvae of Stenophylax mitis McLachlan 1875 and Allogamus hilaris (McLachlan 1876a) (Trichoptera: Limnephilidae: Limnephilini; Vshivkova et al. 2007). Information on the morphology of the larvae is given and the most important diagnostic features are illustrated. In the context of published keys, the larva of Stenophylax mitis keys together with Stenophylax permistus McLachlan 1895, S. vibex (Curtis 1834), Stenophylax crossotus McLachlan 1884, Platyphylax frauenfeldi (Brauer, in Brauer & Löw 1857), Micropterna lateralis (Stephens 1837) and M. sequax McLachlan 1875. These species are easily separated by a combination of the following features: spatial extent of the head spinule areas, setation on femora and on the 9th abdominal dorsum, and on the number of posterior sclerites behind each lateral protuberance. Allogamus hilaris keys with Allogamus uncatus (Brauer, in Brauer & Löw 1857), A. mendax (McLachlan 1876a) and Alpopsyche ucenorum (McLachlan 1876b). These species are very similar except in head width which is < 1.50 mm in A. mendax and A. ucenorum and > 1.61 mm in A. hilaris and A. uncatus; the two species in each of the pairs are not separable. With respect to distribution, S. mitis ranges from the Iberian Peninsula to the Balkan Peninsula and from southern Italy and Greece to the Central European Highlands. Allogamus hilaris is restricted to the Western Alps and the northern half of the Apennine Peninsula. In addition, ecological characteristics are briefly discussed.

Glacial survival and post‐glacial recolonization of an arctic–alpine freshwater insect (Arcynopteryx dichroa, Plecoptera, Perlodidae) in Europe

AbstractAimGeneral models for understanding the climate‐driven processes of post‐glacial colonization in European arctic–alpine species are mainly derived from studies on temperate terrestrial taxa. However, cold‐adapted freshwater species may tolerate or even thrive under colder climatic conditions as flowing water habitats are thermally buffered against freezing and extremely cold temperatures. Here, we investigate the European Pleistocene and Holocene history of the arctic–alpine stonefly Arcynopteryx dichroa.LocationEurope.MethodsWe used two genetic data sets (mitochondrial sequence data and nuclear microsatellite data) to investigate the glacial survival and post‐glacial recolonization routes of A. dichroa. We used species distribution models to critically evaluate our genetic data and phylogeographical interpretations.ResultsAmong 344 sequenced individuals from eight European mountain ranges, 80 unique haplotypes were detected. Of these, 77 haplotypes were endemic to a single mountain range, indicating almost complete lineage sorting. Both sequence and microsatellite data suggested strong population differentiation between mountain ranges. The genetic hotspots were found in the Carpathians, the Balkans and the eastern Alps. The Black Forest and Fennoscandian populations exhibited shared and closely related haplotypes, indicating ancestral polymorphism in two populations that became disjunct due to vicariance or resulting from rare long‐distance dispersal among disjunct northern and southern periglacial populations.Main conclusionsArcynopteryx dichroa is a glacial relict that survived glacial cycles through elevation shifts in isolated periglacial populations in the Pyrenees, the central European highlands, the Carpathians, the Balkans and the eastern Alps. The species probably recolonized the formerly glaciated Fennoscandian range from a refugium in the central European highlands, following the retreat of the ice sheet. This study suggests that aquatic organisms may have reacted differently to Pleistocene climate change compared with terrestrial species.

Sources of loess material for deposits in Poland and parts of Central Europe: The lost Big River

The classical research of Smalley and Leach, investigating the origin of silty material for loess, paid attention to its possible relationship with valleys of the major Central European rivers. In contrast to loess occurring adjacent to the rivers Rhine, Danube, or Dnieper, the origin of silty material in the Central European Highlands and to the Carpathians was not believed to be related to the river valleys, but rather to the extent of the Weichselian Glaciation. The sources of the silt were to be the periglacial deserts at the margins of ice sheets. However, the duration of the loess-forming processes significantly exceeded the time that the ice sheet resided on the Central European Lowlands. Investigations of Late Pleistocene localities in brown coal mines in Lusatia have shed new light on the locations from where the silty material was derived.Research in the Lusatian ice-marginal valley has documented the presence of a large river flowing through the area from Eemian to Late Pleniglacial times. As fluvial deposits now overlie fluvioglacial sediments of the Warthe Stage, a river flowed during post-glacial times through a depression constituted by the Wrocław–Magdeburg–Bremen ice-marginal valley. The deeply incised ice-marginal valley transformed into a fluvial tract. Analyses of sediments and landforms in Lusatia and western Silesia indicate that in Late Pleniglacial times, a radical change of the river network must have occurred in this area. The Odra River, which had earlier headed to the North Sea, was captured by a glacial river flowing in new-formed Baruth–Głogów ice-marginal valley during the Leszno/Brandenburg Phase of the Last Glaciation. At the end of the Last Glacial, the Odra diverted to the north and eventually flowed to the Baltic Sea. The change in the course of the major river caused its tributaries coming from the mountains to bury its former valley with sediments. Deposition of eroded and weathered material took place in the Great Odra Valley under highly changing climatic conditions. Under periglacial conditions, this dry fine-grained material was eroded, transported, and deposited on the areas in front of the mountains, forming the Northern Loess Belt. Its alimentation area was thus the valley of one of the longest European rivers, active from the Warthe Stage until the Late Pleniglacial times (MIS 2–6), and not only a periglacial desert at the foreland to the Last Glacial Maximum (LGM).

From the Western Alps across Central Europe: Postglacial recolonisation of the tufa stream specialist Rhyacophila pubescens (Insecta, Trichoptera)

BackgroundDispersal rates, i.e. the effective number of dispersing individuals per unit time, are the product of dispersal capacity, i.e. a species physiological potential for dispersal, dispersal behaviour, i.e. the decision to leave a habitat patch in favour of another, and connectivity of occupied habitat. Thus, dispersal of species that are highly specialised to a certain habitat is limited by habitat availability. Species inhabiting very stable environments may also adopt a sedentary life-style. Both factors should lead to strong genetic differentiation in highly specialised species inhabiting stable environments. These two factors apply to our model species Rhyacophila pubescens a highly specialised freshwater insect that occurs in tufa springs, a very stable habitat.ResultsWe examined the genetic population structure and phylogeography using range-wide mtCOI sequence and AFLP data from 333 individuals of R. pubescens. We inferred the location of Pleistocene refugia and postglacial colonisation routes of R. pubescens, and examined ongoing local differentiation. Our results indicate intraregional differentiation with a high number of locally endemic haplotypes, that we attributed to habitat specificity and low dispersal rates of R. pubescens. We observed high levels of genetic diversity south of the Alps and genetic impoverishment north of the Alps. Estimates of migrants placed the refugium and the source of the colonisation in the Dauphiné Alps (SW Alps).ConclusionsThis is the first example of an aquatic insect with a colonisation route along the western margin of the Alps to the Central European highlands. The study also shows that specialisation to a stable environment may have promoted a behavioural shift to decreased dispersal rates, leading to stronger local population differentiation than in less specialised aquatic insects. Alternatively, the occurrence of highly specialised tufa spring habitats may have been more widespread in the past, leading to range regression and fragmentation among present day R. pubescens populations.

Artificial ponds: a substitute for natural Beaver ponds in a Central European Highland (Eifel, Germany)?

The European Beaver, once widely distributed across Europe, was almost completely eradicated in the nineteenth century. In the meantime, it has recovered large parts of its distribution range and has increasingly resettled the valleys of the Central European Highlands. In the past, in these same valleys, countless artificial fish and fire-fighting weir ponds, with a water regime similar in size and location to those of the Beaver, were created. In order to assess how near-natural the newt communities of the artificial ponds are, we studied 21 artificial and 22 Beaver ponds in the Eifel, a typical Central European Highland in Germany, using funnel traps. In general, artificial and Beaver ponds supported the same eight amphibian species, whereby the Beaver ponds had on average a larger number of species (4.8 species as opposed to 3.6). The average population size of the two dominant Urodela species, determined by a mark-recapture method, was higher than is usually recorded in other pond types, whereby the influence of the factor “Beaver” pond proved to be either neutral (Triturus alpestris) or positive (Triturus helveticus). The decisive factor for the activity density of both species in the ponds studied was the presence of fish. Artificial ponds probably provide an important substitute for the once common Beaver ponds for at least the majority of woodland species in large areas of Central Europe. This leads to the following conclusions: (1) The destruction of artificial weir ponds in line with the EU Water Framework Directive needs to be critically called into question to prevent avoidable damage to biodiversity. (2) Beaver ponds open undreamt opportunities for amphibian conservation in Europe. The Beaver should therefore be given special consideration and considered a key species for the preservation of biodiversity when preparing relevant EU programmes.

Contrasting patterns of population structure in the montane caddisflies Hydropsyche tenuis and Drusus discolor in the Central European highlands

Summary1. In this study, we compared mitochondrial sequence data (cytochrome oxidase I) to infer the population structure of the two montane caddisflies Hydropsyche tenuis and Drusus discolor. The two species are contrasting examples of montane aquatic insects with insular distributions: D. discolor is restricted to altitudes above 600 m, H. tenuis is limited to the same mountain ranges in Central Europe but inhabits lower altitudes.2. In particular, we ask whether these two species with similar regional distributions show similar patterns of population structure and haplotype diversity, and whether any differences can be attributed to population history and/or autecology.3. To determine the population structure of both species, we applied conventional population genetics analyses to mitochondrial sequence data. We collected and sampled 121 specimens of H. tenuis from 29 sites in 10 different regions of the Central European highlands and 138 individuals of D. discolor from 40 sites in 11 different regions.4. Nine unique haplotypes were identified for H. tenuis and 34 for D. discolor. There were eight variable positions in H. tenuis and 41 in D. discolor. The maximum difference between haplotypes was 0.8% (4 bp) for H. tenuis and 4.2% (21 bp) for D. discolor. We observed haplotype overlap between geographic regions for both species. Analysis of molecular variance showed that two‐thirds of the total variance in H. tenuis was found among regions while in D. discolor, a larger portion of variance was found within regions and populations due to a higher number of haplotypes observed within regions. Mantel test showed a significant relationship between genetic and geographic distance in D. discolor, but no significant relationship in H. tenuis.5. Our analyses show that, despite their very similar overall distribution pattern in Europe, the two species exhibit distinct population structures, which may reflect differences in phylogeographic history, dispersal capabilities, habitat specifity or within‐region geographic occurrence.

Runoff formation in a tile-drained agricultural basin of the Harz Mountain Foreland, Northern Germany

By taking two different tile-drained agricultural basins with porous aquifers in the lowlands of northern Germany as examples, it is demonstrated with an integrated study approach that this type of basin responds similarly to an input as forested mountainous basins with dominant fractured rock aquifers in the central European highlands do. The control mechanism is local rise of pressure heads of aquifers starting with the infiltration process. It is shown that drain laterals in agricultural basins function like fractures and faults in those hard rock basins, i.e. as efficient drain pipe lines. This effect is amplified by hydraulic pressure transmission in the course of single input events, and additionally verified here with the help of artificial and environmental tracers. As a result stream flow is predominantly generated by exfiltrating groundwater. For this process drain laterals constitute fast hydraulic short cuts in the sense of preferential flow paths preferably in case that groundwater tables reach up to the level tile-drain networks.

Beaver ponds as habitat of amphibian communities in a central European highland

Abstract The Eurasian beaver Castor fiber, formerly occurred across the Palaearctic, but was nearly eradicated in the 19th century. Due to reintroductions in the 20th century, beaver populations are increasing and now extend into highland areas. Natural still waters are scarce in highlands of Central Europe. Therefore the question arises, “Are beaver ponds essential habitats for amphibians?”, especially since fishes, predators of amphibian larval stages, also inhabit beaver ponds. We investigated the amphibian fauna of one typical valley in the Eifel, that was colonized by beavers in 1981, and compared areas with and without beaver ponds. All anuran species of the region occupied beaver ponds, including species that were absent (Alytes obstetricans, Bufo bufo and Rana kl. esculenta) or rare (Rana temporaria) in natural waters. Alytes obstetricans obviously benefited from pond construction and the removal of trees by beavers which leads to sunny plots along the slopes of the valley, crucial habitat for this species. The urodelans Salamandra salamandra, Triturus alpestris and Triturus helveticus were widely distributed in beaver ponds. Our results show clearly, that beaver altered landscapes offer high quality habitats for amphibians in our study area. Due to a considerable increase of habitat heterogeneity in impounded streams, the predator Salmo trutta was not able to extirpate the amphibian fauna. We conclude that the historic effects of beavers need to be considered for a proper understanding of patterns of amphibian distribution and habitat requirements in Central European Highlands. Furthermore, beaver-created landscapes will be of future relevance for conservation of endangered species, like Alytes obstetricans.

Spatial patterns of central European pointer years from 1901 to 1971

Three hundred and seventy-seven tree-ring width site chronologies including all eight principal forest tree species within Central Europe (5° to 15°E; 43° to 53°N) are expressed as Cropper-values and mapped using a Geographical Information System (here after referred to as GIS). Spatial classification of positive and negative growth anomalies and their occurrence within altitudinal zones, results in nine differing sub-groups of pointer years. In total, 39 years between 1901 and 1971AD are subdivided into these groups. The other 32 years show only growth anomalies in less than 40% of the research area, and therefore were excluded from further investigations. Climatological interpretation of the growth patterns of the nine groups documents mutual temperature and precipitation forcings. Extreme positive pointer years represent optimal growth conditions, i.e., moderate cool and wet conditions during the growing season. For the other years we summarize (i) warm and wet (warm and dry) springs result in positive (negative) anomalies in the Central European lowlands and (ii) warm (cold) summers result in positive (negative) anomalies in the Central European highlands. In some years, however, similar climatological conditions yield to divergent growth response patterns.

The role of recharge zones, discharge zones, springs and tile drainage systems in peneplains of Central European highlands with regard to water quality generation processes

The hydrogeology, runoff generation and water quality generation in old peneplains of Central Europe built by acid crystalline rocks (such as the Bohemo-Moravian Highland) are described and interpreted in terms of a three-zone concept. The recharge zones are located on flat tops of hills and their soils are mostly permeable. It is mainly through them that the shallow groundwater-bearing formations are loaded with nitrate. The groundwater exfiltrates on the lower parts of slopes (in the so-called transient zone) and in narrow valleys (in the discharge zone), creating dispersed springs and waterlogged areas. In addition, the rapid and shallow flow of perched groundwater down the slope, which takes place during wet periods in the recharge zone and, mainly, in the transient zone, leaches the nitrate from the soil directly to the stream, without necessarily being in contact with the permanent groundwater table of the recharge and the transient zones. Discharge and water quality measurements in the Kopaninský tok experimental catchment (6.7 km 2) were analysed, using a combination of two runoff separation techniques (a digital filter and a simple conceptual model GROUND). Three runoff components were distinguished (direct runoff, interflow and baseflow). There is a weak but significant positive correlation between the stream nitrate concentration on the one hand and either the interflow or the baseflow on the other hand. There is also a weak but significant negative correlation between the stream nitrate concentration on the one hand and either the ratio of direct runoff to total stream flow or the logarithm of this ratio on the other hand, provided that the cases of zero direct runoff are disregarded. A simple mixing model was used to estimate the characteristic nitrate concentrations of individual runoff components. The interflow has the highest characteristic nitrate concentration and is probably the main stream water polluter with nitrate. The baseflow is identified as the likely second main polluter. The differences in water quality between a drainage outlet and a forest spring indicate the importance of a proper nitrogen management in the recharge zones. It is also concluded that the tile drainage and tillage of formerly waterlogged sites, mainly located in transient zones, reduce the opportunity for denitrification of both baseflow and interflow. The ploughed lands in the recharge zones represent an established basis for local agriculture and cannot be easily set aside. Many such lands have been declared as vulnerable to nitrate pollution in order to protect waters against impacts of risky agricultural practices. It is proposed that some waterlogged and drained sites in the transient and discharge zones are set aside rather than the flat ploughed lands on the hill tops. To increase the denitrification, tile drainage runoff from the transient and the discharge zones should be retarded.

GPR images of periglacial slope deposits beneath peat bogs in the Central European Highlands, Germany

Abstract This research investigates the use of ground penetrating radar (GPR) to determine the continuity of periglacial slope deposits under peat bogs. In the Central European Highlands, periglacial slope deposits are a common parent material for soils and play a critical role in determining the nature of chemical and physical processes in soil development. There is a common agreement on the general distribution of these slope deposits, but there is an ongoing debate in German literature concerning the actual age of these deposits. In particular, the youngest head can usually be found under peat bogs of Late Glacial age ( 14 C and pollen stratigraphy) and has lead to a minimum age determination of pre-Alleröd. Stratigraphic investigations were made using drill cores, and GPR was used to define the continuity of the head under the bog. Several examples from southeastern Bavaria are given.

Vegetationsökologische Untersuchungen im Moorkomplex der Meloner Au (niederösterreichisches Waldviertel) als Grundlage für die Entwicklung von Naturschutzstrategien )

Summary Peatlands are at present one of the most important objects for nature conservancy. To guarantee the survival of all the different types of these wetlands, which are characteristic for the large landscape units of Europe, an international strategy has to be worked out, based on knowledge of the condition and distribution of mires all over the continent. In addition, special investigations on the most valuable sites must be carried out to yield detailed information about their development, history, ecology, vegetation and wildlife. To do this as an example for a good conservation strategy, the arguments and facts mentioned above were collected and worked out in one of the most outstandig peatland regions of Austria, the Granit- and Gneis Plateau, which is the southernmost part of the Central European Highlands.

Beiträge zur Ökologie der benthischen Algen des Hochgebirges in den Pyrenäen II. Cyanophyceen und übrige Algengruppen

AbstractLittle research has been made on the litoral algal flora of unpolluted high mountain lakes and streams. Since the algal flora is often used to estimate the water quality, it is of great value to know more about the ecology of benthic forms living under extreme oligotrophic conditions.An investigation was made of the benthic and littoral microphytic vegetation of Esteragne torrent, and Lac de Port‐Bielh in the High Pyrenees. Both waters combine a low calcium content with a consistently basic pH. A comparison of their flora with that of other lakes may help to deal with the problem of whether the algal flora is determined more by the calcium content or the pH.The algal flora of Esteragne torrent differs little from that of low‐calcium streams of the central European highlands. In Lac de Porth‐Bielh there is a distinct depth‐zonation among the dominant algae. The dominant taxa at a depth of 0–0,5 metres are: Schizothrix lacustris f. lutescens, Sch. calcicola, Gloeocapsa tornensis, Pleurocapsa minor with Cyanostylon microcystoides and Hydrococcus cesatii particularly on the undersides of the stones; from 0,5 to 1,5 m: a massive growth of Nostoc zetterstedtii; from 2,5 to 4,5 m: Schizothrix funalis; from 7 m: Nitella flexilis. In addition the lake includes a number of rare and little known forms such as? Onkonema sp., of. Desmosiphon maculans, Lyngbya lachneri, Homeothrix sinensis, Chantransia chalybea v. profunda, Siphononema polonicum status chamaesiphonoides. Green algae were almost completely absent from the upper zones, in contrast to the usual findings. The littoral flora has a very distinctive character, and is not directly comparable with that usually found in lakes with either high or low calcium content. A certain resemblance to lakes with a high calcium content can be found only if all the forms present particularly with lower abundances are considered. The very strong development of lithophytes should be emphasized in contrast to their usually low density in lakes with low calcium content.The systematic section deals with systematic and taxonomic problems in a number of difficult forms.