Simulating the impacts of vegetation structure on the occurrence of a small mammalian carnivore in semi-arid savanna rangelands

Alexander Popp, Monika Schwager, Niels Blaum and Florian Jeltsch

Ecological Modelling, 2007, vol. 209, issue 2, 136-148

Abstract: In arid and semi-arid savannas, species diversity is strongly influenced by structural diversity, which in these systems is characteristically formed by woody vegetation. Shrub encroachment, associated with overgrazing by domestic livestock, changes the structural diversity and hence affects biodiversity. Many investigations have been carried out with focus on the structure building trees, but little is known about the importance of shrubs. Here, we present a spatially explicit and individual-based population model for analysing the influence of shrub encroachment on the occurrence of yellow mongooses (Cynictis penicillata) in the Southern Kalahari, South Africa. This analysis is based on field investigations in Southern Africa. The results of the modelling study are in line with the results of a field study, in which the same unimodal relationship between shrub cover and yellow mongoose abundance was found. The model could explain this relationship by the need of shrubs as protective structures on the one hand, and the need of foraging habitat in the grass matrix on the other hand. To evaluate the factors influencing the population dynamics at different levels of shrub encroachment we carried out an extensive sensitivity analysis. Finally, we determined a range of existence of the yellow mongoose for various shrub covers. Model results indicate a lower and an upper limit of critical shrub densities at 1% and 38%, respectively. These limits indicate the range in shrub cover allowing the persistence of the yellow mongoose in the Southern Kalahari.

Keywords: Yellow mongoose; Rangeland; Individual-based model; Shrub encroachment; Spatial explicit; Structural diversity (search for similar items in EconPapers)
Date: 2007
References: View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0304380007003250
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:ecomod:v:209:y:2007:i:2:p:136-148

DOI: 10.1016/j.ecolmodel.2007.06.017

Access Statistics for this article

Ecological Modelling is currently edited by Brian D. Fath

More articles in Ecological Modelling from Elsevier
Bibliographic data for series maintained by Catherine Liu ().