Water availability, bedrock, disturbance by herbivores, and climate determine plant diversity in South‑African savanna

0562145 - BÚ 2023 RIV GB eng J - Journal Article
Hejda, Martin - Čuda, Jan - Pyšková, Klára - Zambatis, G. - Foxcroft, L. C. - MacFadyen, S. - Storch, D. - Tropek, Robert - Pyšek, Petr
Water availability, bedrock, disturbance by herbivores, and climate determine plant diversity in South‑African savanna.
Scientific Reports. Roč. 12, č. 1 (2022), č. článku 338. ISSN 2045-2322. E-ISSN 2045-2322
R&D Projects: GA ČR GA18-18495S
Institutional support: RVO:67985939 ; RVO:60077344
Keywords : plant species diversity * species richness * South-African savanna * Krüger National Park * woody vegetation cover * herbaceous vegetation * elephants * land use * fire * rainfall * responses
OECD category: Ecology; Plant sciences, botany (BC-A)
Impact factor: 4.6, year: 2022
Method of publishing: Open access
https://doi.org/10.1038/s41598-021-02870-3

To identify factors that drive plant species richness in South‑African savanna and explore their relativeimportance, we sampled plant communities across habitats differing in water availability, disturbance,and bedrock, using the Kruger National Park as a model system. We made plant inventories in 60plots of 50 × 50 m, located in three distinct habitats: (i) at perennial rivers, (ii) at seasonal rivers withwater available only during the rainy season, and (iii) on crests, at least ~ 5 km away from any watersource. We predicted that large herbivores would utilise seasonal rivers’ habitats less intensely thanthose along perennial rivers where water is available throughout the year, including dry periods.Plots on granite harboured more herbaceous and shrub species than plots on basalt. The dry crestswere poorer in herb species than both seasonal and perennial rivers. Seasonal rivers harboured thehighest numbers of shrub species, in accordance with the prediction of the highest species richnessat relatively low levels of disturbance and low stress from the lack of water. The crests, exposedto relatively low pressure from grazing but stressed by the lack of water, are important from theconservation perspective because they harbour typical, sometimes rare savanna species, and so areseasonal rivers whose shrub richness is stimulated and maintained by the combination of moderatedisturbance imposed by herbivores and position in the middle of the water availability gradient. Tocapture the complexity of determinants of species richness in KNP, we complemented the analysis ofthe above local factors by exploring large‑scale factors related to climate, vegetation productivity,the character of dominant vegetation, and landscape features. The strongest factor was temperature,areas with the highest temperatures reveal lower species richness. Our results also suggest thatColophospermum mopane, a dominant woody species in the north of KNP is not the ultimate cause ofthe lower plant diversity in this part of the park.
Permanent Link: https://hdl.handle.net/11104/0334561