Potential influence of global climate change on ungulates, predators and tourists in African national parks
Zusammenfassung der Projektergebnisse
The potential impact of global climate change on species diversity, trophic interactions, ecosystem functions and ecosystem services is poorly understood. African savannahs provide an interesting study system as they harbour a unique density and species richness of ungulates and large mammalian predators. They also provide valuable ecosystem services in terms of wildlife tourism, a major income for many African countries. Climatic factors, vegetation, ungulates, large mammalian predators and tourist numbers are intricately linked. Some of these links have been studied, especially at regional spatial scales. However, links among all components, especially including tourist numbers have not been tested quantitatively. We planned to analyse the quantitative relationships between climatic factors, vegetation, ungulates, large mammalian predators, and tourist numbers by analysing census data and visitor statistics across multiple African Protected Areas (PAs) (n = 64) using path analyses. We also analysed the same relationships at a regional spatial scale within one national park with a large rainfall gradient, Kruger National Park, by conducting own counts on mammals and tourists along 78 road transects of 5 km length. We found significant relationships between climatic factors, large mammal densities and tourist numbers across 64 African PAs that were also influenced by travel cost, park quality and park management. We found in particular a positive association between large predator densities and tourist numbers. Similarly, we found within Kruger National Park high visitor numbers at transects with high sighting probabilities of large predators, while other factors, e.g. ungulate densities or infrastructure, were only weakly associated with visitor numbers. Expanding this study to four PAs in southern Africa, Etosha, Chobe, Kruger National Parks, Hluhluwe-Imfolozi Park), covering a large environmental gradient, and increasing the sample size to 196 road transects allowed to test the effect of specific metrics of species diversity, e.g. species richness of rare ungulates or of large predators, on visitor numbers at transects. Mammal diversity metrics related positively to visitor numbers along transects. Specific subcomponents of mammal diversity, especially the richness of predators, but also of rare ungulate species, highly influenced the distribution of visitors in the PAs. Finally, we expanded our framework towards testing the relationship between supply and demand for large mammal species in wildlife tourism. To assess the demand for large mammals, we conducted a social survey with 651 questionnaires across the same four PAs. We tested whether the trophic level and body size of mammals influenced the mismatch between supply and demand. Results showed that a higher supply of large mammal species increased the expectation to see a species, whereas supply did not affect the hopes to see a specific species. Analyses of mismatches revealed that predator species were more demanded in relation to their supply than ungulates; patterns were consistent across the four PAs. Finally, we addressed relationships between mammal densities, vegetation and visitor satisfaction. We found mostly non-linear relationships between vegetation density, mammal densities and wildlife tourists’ responses. In particular, the easiness to spot animals dropped at thresholds of high vegetation density and at mammal densities lower than 46 individuals per road transect. Tourists’ satisfaction declined linearly with vegetation density and dropped at mammal densities smaller than 26 individuals per transect. To conclude, we found that multiple factors influenced wildlife tourism across a multitude of PAs; a particularly important factor was biodiversity, in particular the density of predators. Correspondingly, wildlife tourists within and across four PAs were primarily attracted by large predators. We propose that the quantification of supply-demand mismatches can be used to identify charismatic species and relevant species’ traits, and can be applied for wildlife tourism assessments across as well as within regions. Supply-demand analyses provide a useful framework and deliver indicators for better assessing cultural ecosystem services involving wildlife and nature-based tourism, and can be used for conservation management.
Projektbezogene Publikationen (Auswahl)
- (2016): Biodiversity, scenery and infrastructure: factors driving wildlife tourism in an African savannah national park. Biological Conservation 201: 60-68
Grünewald, C., M. Schleuning, and K. Böhning-Gaese
(Siehe online unter https://doi.org/10.1016/j.biocon.2016.05.036) - (2017): Mismatches between supply and demand in wildlife tourism: insights for assessing cultural ecosystem services. Ecological Indicators 78: 282-291
Arbieu, U., C. Grünewald, B. Martín-López, M. Schleuning, and K. Böhning-Gaese
(Siehe online unter https://doi.org/10.1016/j.ecolind.2017.03.035)
