کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4378518 1617541 2007 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Simulating the impacts of vegetation structure on the occurrence of a small mammalian carnivore in semi-arid savanna rangelands
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک بوم شناسی، تکامل، رفتار و سامانه شناسی
پیش نمایش صفحه اول مقاله
Simulating the impacts of vegetation structure on the occurrence of a small mammalian carnivore in semi-arid savanna rangelands
چکیده انگلیسی

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.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ecological Modelling - Volume 209, Issues 2–4, 16 December 2007, Pages 136–148
نویسندگان
, , , ,