Biodiversitätsmanagement mit Wasserbüffeln in renaturierten Feuchtgebieten

The use of water buffalos for landscape maintenance started ten years ago in Germany. Now, more than 2,100 buffalos are kept by about 90 breeders, and first results concerning their usefulness for landscape management are available. Buffalos are mainly used on particularly wet sites which cannot be grazed by cattle or other domestic animals. Although grazing of wetlands, river banks and water bodies is still controversial, early results from literature and our own research clearly indicate the beneficial impact of moderate grazing on such sites for birds, amphibians, vegetation and insects. This paper presents a short literature review and the first results of the BUBALUS project at Brandenburg University of Technology (BTU) and general experience from other projects.Seit etwa zehn Jahren gibt es in Deutschland den verstärkten Trend, Wasserbüffel zu halten. Inzwischen gibt es mehr als 2.100 Wasserbüffel bei mehr als 90 Haltern. Erste Ergebnisse ihrer Eignung als Landschaftspfleger in Feuchtgebieten sind nun verfügbar. Die Büffel werden überwiegend auf besonders nassen Standorten eingesetzt, die für die Haltung von Rindern oder anderen Haustieren nicht geeignet sind. Obwohl die Beweidung von Nassstandorten, Ufern und Gewässern noch immer umstritten ist, zeigen die verfügbaren Ergebnisse den Nutzen für Vögel, Amphibien, Insekten und Vegetation. Dieser Artikel gibt eine kurze Übersicht zu relevanter Literatur sowie erste Ergebnisse des BUBALUS Projektes der Brandenburgischen Technischen Universität Cottbus (BTU) sowie generelle Erfahrungen aus anderen Projekten

Ground beetles of disturbed landscapes in Lower Lusatia–post mining landscapes

Die Niederlausitz befindet sich im Osten Deutschlands und ist überwiegend im Süden Brandenburgs gelegen. Sie ist in der Vergangenheit durch großflächigen Braunkohlebergbau und durch militärischen Übungsbetrieb stark anthropogen überprägt worden. Seit 1945 wurden durch den Tagebau in der Niederlausitz knapp 80.000 ha Fläche in insgesamt 42 Tagebauen in Anspruch genommen (DEBRIV 1997, DREBENSTEDT 1998) und liegen heute überwiegend als Bergbaufolgelandschaften (BFL) vor. Bezogen auf die Niederlausitz können etwa 1/5 der Fläche der Niederlausitz als gestörte Landschaften bezeichnet werden. Bergbaufolgelandschaften heben sich durch die ehemalige Nutzung deutlich von der Kulturlandschaft ab und werden hier beispielhaft für gestörte Landschaften betrachtet. Bergbaufolgelandschaften stellen großflächige Inseln in der Kulturlandschaft dar, die sich nach der Verkippung durch sterile Substrate auszeichnen, mit z. T. extremem bodenkundlichen und kleinklimatischen Verhältnissen. Nach Rekultivierung der Substrate oder nach natürlicher Sukzession sind von großen offenen Sandflächen, verschiedenen frühen Sukzessionstadien bis hin zu Forsten verschiedenste Vegetationsstadien zu finden. Eine Gemeinsamkeit aller Bergbaufolgelandschaften liegt in der Neubesiedlung durch Laufkäfer und primären Sukzession der Zönosen.Lower Lusatia, situated in south of Brandenburg / Germany is a highly disturbed landscape. Fifth part of area was disturbed or devastated by military trainig or brown coal mining in the past. Leftovers of mining activities are large dumps with highly acidic soils under primary succession. Many sites were recultivated and afforrested. But also many recultivated landscapes have extreme site conditions (low pH, early vegetation stages). 199 Ground beetle species are yet known from post mining landscapes in Lower Lusatia. Actually a high amount of endangered species can be found. All ground beetle species of open sandy soils and psammophytic grasslands and most species of rural vegetation and forests in Brandenburg can be found in post mining landscapes. Species inventory of Calluna-heathland, wetlands and riparian banks is incomplete and consist of only 40 – 60 % of possible species. Missing species belong to very rare and extinct species in Brandenburg or to species with highly specialised habitat requirements (moor, saline habitats, etc.) which cannot be found yet in post mining landscape

The willingness to pay (WTP) for the conservation of wild animals: Case of the Derby Eland (Taurotragus derbianus gigas) and the African wild dog (Lycaon pictus) in North Cameroon

Data on the perception of and willingness to pay (WTP) for the conservation of the Derby Eland and the African Wild Dog in North Cameroon were collected from August to October 2004 using administered questionnaires. The results show a positive attitude of respondents towards wildlife conservation. They indicated willingness to support actions geared towards the conservation of endangered species in National Parks. WTP often leads to a social dilemma of a choice between one’s self interests and community or group interest. This choice often affects attitudes, motivations, perceptions, and values leading to different outcomes at the individual and group levels. The level of awareness of the need for wildlife conservation of endangered species in Cameroon National Parks is high and thus leads to a high approval of conservation plans. As a result respondents expressed the view that individuals have a moral obligation to cooperate in wildlife conservation effort. Where private operators and governments manage hunting zones (ZIC) and National Parks respectively, the results are not always excellent as they should be. Funds generated from taxes and individual contributions for specific conservation measures are neither used by officials for wildlife conservation as hoped nor to compensate farmers for damages caused by wildlife. Even though a positive environmental attitude influences the WTP for environmental goods, the WTP for environmental goods is certainly out of surplus and personal unique dispositions, perception, organization, understanding and appreciation of the environment. However, under the present management scheme, local communities around Faro and Benoué National Parks benefit from tax quotas. Primarily because of the attractiveness and beauty of the Derby Eland and the African Wild Dog, respondents expressed favourable attitude towards their conservation despite their attractive tendencies and notorious labels as animals of prey.Key words: Conservation, gender, perception, willingness to pay, ecotourism

Impact of hydraulic forces on the passage of round goby (Neogobius melanostomus), gudgeon (Gobio gobio) and bullhead (Cottus gobio) in a vertical slot fish pass

Every fish migrating upstream through vertical slot fish passes must swim through slots, where the resistance force of flowing water could affect the passage success. We measured the hydraulic force acting on the body of preserved benthic fish in a vertical slot at different water discharge rates (80 and 130 L/s) to compare the hydraulic burden individual fish species (round goby Neogobius melanostomus Pallas, 1814, gudgeon Gobio gobio L. and bullhead Cottus gobio L.) must overcome. The forces measured in three spatial axes were then compared to acoustic Doppler velocity measurements and the passage probability of 39–45 live fish per species. Passage probability reduction of 28.26% for round goby and 39.29% for bullhead was observed at the higher water discharge. Gudgeon showed increased numbers of passages and approaches when larger hydraulic forces were experienced at 130 L/s compared to the lower water discharge. Gudgeon experienced significantly lower hydraulic forces (mean 0.27 N ± 0.12 standard deviation) compared to round goby (mean 0.32 N ± 0.12 SD) and bullhead (0.35 N ± 0.14 SD). Potentially, the increased hydraulic forces at the higher water discharge contributed to the reduction in passages in round goby and bullhead. That gudgeon behaved differently from the other species illustrates how fish species deal differently with flowing water and the hydraulic forces experienced. Our approach provides a species-oriented assessment of the flow field in ecologically relevant fish passes. These findings represent an important step towards the development of purposeful fish pass designs, which is essential for ecosystem-oriented river connectivity

Elemental Content of Anagen Hairs in a Normal Caucasian Population Studies with Proton Induced X-Ray Emission (PIXE)

The elemental content of anagen hair fibers in a Caucasian population of healthy females and males in the age range 10-69 years was performed to constitute a baseline for further studies of pathological conditions. Proton induced X-ray emission (PIXE) analyses were performed on single hair fibers in triplicates from 103 individuals in order to determine sulfur, zinc, calcium, and chlorine content. The hair fibers were all anagen hairs collected from a site little influenced by genetic and hormonal influences 1.5 cm above the right ear of the probands. An area 5-8 mm from the follicle bottom was chosen for minimize effect the of analysis in all cases hair-do contamination. The average sulfur content was 0.049 g/g and the average zinc content 170 μg/g. These results were not significantly influenced by chloroform/ethanol rinsing before analysis. The calcium and chlorine contents were 330 μg/g and 0.0033 g/g respectively. The latter data are expected to be more seriously influenced by external factors (e.g., contamination) than sulfur and zinc. No correlation between elemental concentration and sex was found for sulfur and zinc in the present material. PIXE analysis of single hair fibers yields valuable information on the elemental composition of hair fibers and can be rapidly and efficiently performed after simple mounting procedures

Flow, force, behaviour: assessment of a prototype hydraulic barrier for invasive fish

Migration barriers being selective for invasive species could protect pristine upstream areas. We designed and tested a prototype protective barrier in a vertical slot fish pass. Based on the individuals’ swimming responses to the barrier flow field, we assumed this barrier would block the ascension of the invasive round goby, but allow comparable native species (gudgeon and bullhead) to ascend. The barrier was tested in three steps: flow description, quantification of forces experienced by preserved fish in the flow field, and tracking the swimming trajectories of ca. 43 live fish per trial and species. The flow and the forces were homogenous over the barrier, though gudgeon experienced significantly smaller forces than round goby or bullhead. The swimming trajectories were distinct enough to predict the fish species with a random forest machine learning approach (92.16% accuracy for gudgeon and 85.24% for round goby). The trajectories revealed round goby and gudgeon exhibited increased, but varied, swimming speeds and straighter paths at higher water discharge. These results suggest that passage of round goby was prevented at 130 L/s water discharge, whereas gudgeon and bullhead could pass the barrier. Our findings open a new avenue of research on hydraulic constructions for species conservation

Comparative swimming performance and behaviour of three benthic fish species: The invasive round goby (Neogobius melanostomus), the native bullhead (Cottus gobio), and the native gudgeon (Gobio gobio)

Efforts to restore river ecosystem connectivity focus predominantly on diadromous, economically important fish species, and less attention is given to nonmigratory, small‐bodied, benthic fish species. Data on benthic fish swimming performance and behaviour in comparison with ecologically similar native species are especially relevant for the study of one of the most successful invaders in the last decades: the Ponto‐Caspian gobiid species Neogobius melanostomus. To evaluate future measures against its further upstream dispersal, we conducted comparative swimming performance and behaviour experiments with round goby and two native species: the European bullhead (Cottus gobio) and the gudgeon (Gobio gobio). Experiments in a swim tunnel revealed a high variation in the swimming performance and behaviour within and among the three species. Gudgeon performed best in both U$_{crit}$ and U$_{sprint}$ experiments and displayed a rather continuous, subcarangiform swimming mode, whereas bullhead and round goby displayed a burst‐and‐hold swimming mode. Experiments in a vertical slot pass model, which contained a hydraulic barrier as a challenge to upstream movement, confirmed the high swimming performance of gudgeon. Gudgeon dispersed upstream even across the hydraulic barrier at the highest flow velocities. Round goby showed a higher capability to disperse upstream than bullhead, but failed to pass the hydraulic barrier. Our results on comparative swimming performance and behaviour can inform predictive distribution modelling and range expansion models, and also inform the design of selective barriers to prevent the round goby from dispersing farther upstream

Flow field-induced drag forces and swimming behavior of three benthic fish species

Modern ethohydraulics is the study of the behavioral responses of swimming fish to flow fields. However, the exact drag forces experienced by fish remain poorly studied; this information is required to obtain a better understanding of the behavioral responses of fish and their current resistance strategies. We measured near-ground frontal drag forces on preserved individuals of three benthic fish species, round goby ( Neogobius melanstomus ), gudgeon ( Gobio gobio ) and bullhead ( Cottus gobio ), in a flow channel. The forces were compared to acoustic Doppler velocity (ADV) measurements and fish tracking data based on video observations of live fish in the flow channel. Overall, we observed drag coefficients (C D ) of ∼10 −3 at Reynolds numbers ∼10 5 . The frontal drag forces acting on preserved fish with non-spread fins ranged from -1.96 mN*g -1 (force per fish wet weight, velocity 0.55 m*s -1 ) to 11.01 mN*g -1 (velocity 0.85 m*s -1 ). Spreading the fins strongly increased the drag forces for bullhead and round goby. In contrast, the drag forces were similar for gudgeon with spread fins and all fish with non-spread fins. Video tracking revealed no clear relationship between the position of the fish in the flow field and the forces experienced by the preserved fish at these positions. Collectively, these results suggest that i) the differences in frontal drag forces between species are small in homogenous flow, ii) individuals chose their position in the flow field based on factors other than the drag forces experienced, and iii) whether fins are spread or non-spread is an essential quality that modulates species-specific differences. The methodology and results of this study will enable integration of flow measurements, fish behavior and force measurements and inform ethohydraulics research. More advanced force measurements will lead to a detailed understanding of the current resistance strategies of benthic fish and improve the design of fish passes