Weingarth K.,Albert Ludwigs University of Freiburg |
Heibl C.,Bavarian Forest National Park |
Knauer F.,University of Veterinary Medicine Vienna |
Zimmermann F.,KORA Carnivore ecology and wildlife management |
And 2 more authors.
Animal Biodiversity and Conservation | Year: 2012
First estimation of Eurasian lynx (Lynx lynx) abundance and density using digital cameras and capture-recapture techniques in a German national park.- Eurasian lynx are individually identifiable by their unique coat markings, making them ideal candidates for capture-recapture (CMR) surveys. We evaluated the use of digital photography to estimate Eurasian lynx population abundance and density within the Bavarian Forest National Park. From November 2008 to January 2009 we placed 24 camera trap sites, each with two cameras facing each other (on well-used walking tracks). The units were placed based on a systematic grid of 2.7 km. We captured five independent and three juvenile lynx and calculated abundance estimates using Program Mark. We also compared density estimates based on the MMDM method (Mean Maximum Distance Moved) from telemetry data (1/2MMDMGPS) and from camera trapping data (1/2MMDMCAM). We estimated that in an effectively sampled area of 664 km2 the Eurasian lynx density was 0.9 individuals/100 km2 with 1/2MMDMCAM. The Eurasian lynx density calculated with 1/2MMDMGPS was 0.4 individuals/100 km2 in an effectively sampled area of 1,381 km2. Our results suggest that long-term photographic CMR sampling on a large scale may be a useful tool to monitor population trends of Eurasian lynx in accordance with the Fauna-Flora-Habitat Directive of the European Union. © 2012 Museu de Ciències Naturals de Barcelona.
Novak M.,Czech Geological Survey |
Jackova I.,Czech Geological Survey |
Curik J.,Czech Geological Survey |
Stepanova M.,Czech Geological Survey |
And 8 more authors.
Ecosystems | Year: 2016
Nitrogen (N) isotope systematics were investigated at two high-elevation ombrotrophic peat bogs polluted by farming and heavy industry. Our objective was to identify N sources and sinks for isotope mass balance considerations. For the first time, we present a time-series of δ15Ν values of atmospheric input at the same locations as δ15Ν values of living Sphagnum and peat. The mean δ15Ν values systematically increased in the order: input NH4 + (−10.0‰) < input NO3 − (−7.9‰) < peat porewater (−5.6‰) < Sphagnum (−5.0‰) < shallow peat (−4.2‰) < deep peat (−2.2‰) < runoff (−1.4‰) < porewater N2O (1.4‰). Surprisingly, N of Sphagnum was isotopically heavier than N of the atmospheric input (P < 0.001). If partial incorporation of reactive N from the atmosphere into Sphagnum was isotopically selective, the residual N would have to be isotopically extremely light. Such N, however, was not identified anywhere in the ecosystem. Alternatively, Sphagnum may have contained an admixture of isotopically heavier N. Ambient air contains such N in the form of N2 (δ15ΝN2 = 0‰). Because high energy is required to break the triple bond, microbial N fixation is likely to proceed only under limited availability of pollutant N. Also for the first time, a δ15Ν comparison is presented between anoxic deeper peat and porewater N2O. Isotopically light N is removed from anoxic substrate by denitrification, whose final product, N2, escapes into the atmosphere. Porewater N2O is an isotopically heavy residuum following partial N2O reduction to N2. © 2016 Springer Science+Business Media New York
Roder J.,University of Wurzburg |
Bassler C.,Bavarian Forest National Park |
Brandl R.,University of Marburg |
Dvorak L.,Municipal Museum Marianske Lazne |
And 7 more authors.
Forest Ecology and Management | Year: 2010
Norway Spruce is the economically most important tree species in Europe and has been cultivated in plantations on a large-scale at low elevations, far outside its natural range. In the Bohemian Forest, it naturally occurs in pure stands above 1150 m a.s.l. and as a mixed tree species from 650 to 1150 m a.s.l. An understanding of natural distributions and the diversity along temperature gradients at various elevations is important for conservation, pest management, and predictions of future species assemblages by global warming. Here we investigated the species richness of canopy arthropods in spruce trees along a gradient from 300 to 1300 m a.s.l. using flight-interception traps. We analyzed species richness by combining diversity partitioning with a moving window approach after standardizing sample size per plot. Total richness decreased linearly as the elevation increased, which reflected declining temperatures and a declining regional species pool. Phytophages (herbivores excluding xylophages) were the most influenced. Richness did not peak at the transition zones of the three ecological elevation zones, neither for all species, nor for any of the separate functional groups. However, the proportion of both beetle and true bug spruce specialists significantly increased with elevation and actually doubled in richness above 1000 m a.s.l., where spruce is naturally dominating. Our results indicate that even planted spruce trees at lower elevations maintain high levels of species richness. Further climate warming will promote overall species richness, especially of phytophages, at all elevations. However, spruce specialists may be seriously threatened by global warming. © 2010 Elsevier B.V. All rights reserved.
Weingarth K.,Bavarian Forest National Park |
Weingarth K.,TU Munich |
Zeppenfeld T.,Bavarian Forest National Park |
Zeppenfeld T.,University of Gottingen |
And 8 more authors.
Biodiversity and Conservation | Year: 2015
A tool commonly used in wildlife biology is density estimation via camera-trap monitoring coupled with capture–recapture analysis. Reliable regional density estimations of animal populations are required as a basis for management decisions. However, these estimations are affected by the session design, such as the length of the monitoring session, season, and number of trap sites. This method is regularly used to monitor Eurasian lynx (Lynx lynx) which mostly occupy the forested mountain ranges in Central Europe. Here we used intensive field sampling data of a major Central European lynx population to investigate (1) the optimal monitoring session length considering the trade-off between population closure and number of recaptures for density estimates, (2) the optimal time window within the year considering the stability of density estimates, detection probability, recapture number, and reproduction, and (3) the number of trap sites and trap spacing required to achieve robust density estimates. Using two closure tests, we found that 80 days are the minimum to ensure adequate data quality. A spatially explicit capture–recapture model revealed the best monitoring period to be late summer to early winter. Based on our results, we recommend for similar management units of comparable size (~300 km2) and similar recapture numbers to sample for at least 80 days in autumn with traps spaced about every 2.5–3 km. Our results also indicated that stable density estimates could still be maintained when the sampling area is enlarged to 760 km2 with trap spacing every 5–6 km if session lengths are increased. © 2015, Springer Science+Business Media Dordrecht.
Belotti E.,Czech University of Life Sciences |
Cerveny J.,Czech University of Life Sciences |
Sustr P.,Sumava National Park Administration |
Sustr P.,Academy of Sciences of the Czech Republic |
And 4 more authors.
Wildlife Biology | Year: 2013
The choice of foraging areas by large carnivores can be driven both by prey abundance and landscape attributes and it is likely that the relative importance of these two components changes on different spatial scales. In the Bohemian Forest (southwestern Bohemia, Czech Republic), we focused on the effect of microhabitat. We tested if Eurasian lynx Lynx lynx hunted merely in areas where its main prey, roe deer Capreolus capreolus and red deer Cervus elaphus, occurred ('prey-occurrence hypothesis') or if there were fine-scale habitat features that increased prey catchability ('landscape hypothesis'). Fine-scale habitat features were recorded at sites where an ungulate had been killed and located using telemetry or by chance (in winter: N = 29 roe deer, N = 18 red deer; in summer: N = 33 roe deer, N = 5 red deer). We compared these features with those recorded at locations where live red or roe deer were recorded using telemetry (N = 100 per species per six-month period). In winter, lynx killed both roe and red deer at sites where there was a greater heterogeneity in terms of visibility than at sites where live ungulates were recorded, i.e. at kill sites there were both good stalking cover and good visibility. In addition, the risk of predation for red deer was negatively correlated with tree density. In summer, the risk of predation for roe deer was not associated with any of the habitat variables measured. Thus, the presence of a kill was associated with particular fine-scale habitat features in winter, while in summer it was simply associated with where prey occurred. A deeper understanding of the type of habitat favoured by lynx is fundamental to the management and conservation of this species. Based on our results, forest management should ensure that the level of habitat heterogeneity is favourable for lynx. © Wildlife Biology, NKV.