Description
Heterogeneity or resource patchiness is a global theme in modern ecology. A patchy resource environment often leads to areas of high faunal and floral diversity and therefore high conservation value. On a large scale abiotic factors regularly drive resource patchiness but on a small scale the causes of heterogeneity are more varied and complex. At this scale biotic drivers often interact with abiotic drivers. In this study White rhino (Ceratotherium simum) middens and three genera of termite mounds are examined as key drivers of small-scale resource heterogeneity in savannah grasslands. We investigated how the impact of both biotic drivers interacted with one of the main abiotic drivers in the system, rainfall.Rhino and termites can both act as ecosystem engineers, creating nutrient ‘hotspots’ on similar spatial and temporal scales. We compared and contrasted the effects of these agents in creating and maintaining heterogeneity in the savannah grass landscape under low and high rainfall conditions.We selected ten sites (five wet and five dry) in Hluhluwe iMfolozi Park, South Africa. At each site transects were laid out around rhino middens (dung heaps) and termitaria (termite mounds). On these transects we recorded the species present, ground cover and biomass of all plants within 1x1m quadrats. Additionally, we took paired grass samples adjacent to, and away from, the mounds and middens. These samples were then analysed for various nutrients including C, N and P.Plant diversity was higher around both middens and termitaria for distances of greater than 5 meters away from these features. Plants adjacent to mounds and middens were of higher quality in terms of C:N ratios than those in the plots further away. Both the impact on plant diversity and plant quality was stronger in areas of relatively high rainfall.These results indicate that both rhino and termites play a significant and varied role in creating and maintaining heterogeneity and should be considered important in the functioning of savannah ecosystems.| Periode | 11-feb.-2009 |
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| Evenementstitel | Netherlands Annual Ecology Meeting 2009 |
| Evenementstype | Conference |
| Conferentienummer | 2 |
| Organisator | Netherlands Ecological Research Network (NERN) |
| Locatie | Lunteren, NetherlandsToon op kaart |
| Mate van erkenning | International |