University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Markus Immitzer
(2011):
Modellierung der Habitateignung für das Birkhuhn (Tetrao tetrix) im Südosten des Kasberges (Oberösterreich) unter besonderer Berücksichtigung anthropogener Störungen .
Master / Diploma Thesis - Institut für Wildbiologie und Jagdwirtschaft (IWJ),
BOKU-Universität für Bodenkultur,
pp 82.
UB BOKU
obvsg
- Abstract:
- This study was initiated by a forest enterprise, aiming at a better knowledge of local occurrences of black grouse (Tetrao tetrix) and of the habitat suitability. In study plots, located on a 100x100m grid, the main habitat parameters and indirect signs of black grouse were recorded. From a total of 251 study plots indirect signs were found in 86 cases. Based on these data, two different methods of habitat suitability modeling were applied: First, a knowledge-based, mechanistic approach was used to describe habitat suitability, the so-called HSI (Habitat Suitability Index) model. Here, two HSI-models with different numbers of input parameters were tested. Model 1 was based on the study of Erber & Reimoser (2000).The less complicated model 2 was developed by Zohmann & Nopp-Mayr (2009). Both models classified the investigation area as black grouse habitat of medium quality. The results from model 1 had a very small range of HSI-values, not permitting a detailed differentiation between the sample plots; model 2, on the other hand, provided results with a broader range of HSI-values and indicated a significant statistical relationship between HSI-value and indirect signs of black grouse presence. The second method involved a logistic regression (LR) model to identify main parameters of the spatial distribution of black grouse, taking black grouse presence/absence as response variable. The final model included three explanatory variables (elevation, canopy cover of trees <5m, hiking trail) and one interaction term (canopy cover of trees >5m x cover of grasses and/or herbs). This LR model correctly classified 76% of the study plots in terms of black grouse presence or absence. A suitable black grouse habitat is characterized by an intermediate elevation, high canopy cover of wooded plants with a height <5m and absence of hiking trails. These results confirm the negative impact of human disturbance on the spatial distribution of black grouse by a non-invasive method.
- Beurteilende(r): Hackländer Klaus
- 1.Mitwirkender: Zohmann-Neuberger Margit
- 2.Mitwirkender: Nopp-Mayr Ursula