Increasingly frequent and severe droughts under climate change are expected to have major impacts on vegetation worldwide. However, research date has focused tree vulnerability drought in forests. Less is known about trees savannas, where a sparse layer coexists with grass. These tree-grass interactions (often mediated by fire herbivory) shape savanna ecology, confound predictions of how strongly might affect trees. On the one hand, physiologically stressful, which could harm be exacerbated...

ABSTRACT Intraspecific variation in adaptation to herbivory has been studied juvenile (sapling) and adult (reproductive) stages of woody species African savannas, but not at the early seedling stage. We hypothesized that, among Vachellia commonly occurring spinescence increases growth rate decreases after herbivory, these responses would be expressed most strongly populations with slower growing seedlings. Seedlings V. nilotica , tortilis karroo were grown from seeds different within...

Abstract It is assumed that the phytochemistry of browse species protects their biomass and nutrients against herbivory. In this study we were primarily interested in (i) seasonal phenology‐related variations leaf chemistry, (ii) chemistry‐related feeding behaviour domestic goats. Such knowledge would guide management‐orientated modelling browse–browser interactions seasonal, subtropical zones where goats are abundant. The studied typical semiarid savannas southern Africa: Grewia...

Herbivory and fire are known to shape plant community structure function in savanna ecosystems worldwide, yet these drivers increasingly being altered their behaviour, or completely excluded. Furthermore, herbaceous responses rainfall semi-arid arid savannas may outweigh the effects of herbivory fire, especially nutrient-rich ecosystems. Despite considerable recognition systems, few studies consider grasses forbs as distinct functional entities. To address this shortcoming, we used long-term...

Abstract The Nkuhlu large‐scale long‐term exclusion experiment in Kruger National Park was designed to study the effects of large herbivores on vegetation. One treatment excludes elephants, another all larger than hares and one comprises an open, control area. Vegetation monitoring implemented 2002 when a baseline survey conducted prior exclusion. Monitoring repeated 5 years after Data from surveys were analysed establish how structure composition woody vegetation had changed herbivore...

Ecological models to explain savanna heterogeneity and functioning weakly represent herbaceous forbs, which inevitably created knowledge gaps regarding the diversity ecology of forbs. Forbs constitute over 70% semi-arid species richness. The aim this study was therefore (i) identify forb that potentially form part herbivore diet, (ii) determine browsing intensity across a granitic catenal sequence. Localized contrasts between nutrient-poor dystrophic uplands nutrient-rich eutrophic...

"Miombo Woodlands in a Changing Environment: Securing the Resilience and Sustainability of People Woodlands." African Journal Range & Forage Science, 38(2), pp. 188–189

We investigated the indirect influence of mammalian herbivores on invertebrates, by utilising long-term herbivore exclosures in Kruger National Park. The span three distinct habitat types (crest, footslope and riparian) a catena. By performing invertebrate collections control area we were able to assess effect herbivory community if this varied across types. Our results indicate that large (notably elephants) had significant negative effects total abundance, while medium-sized affected...

Acacia karroo Hayne is the dominant invading species in semi-arid savannas of South Africa and an ecological threat our modern era. This study investigated preference intake rates by goats when fed A. coppice sprouts different basal diameter sizes, viz. 3 mm, 4 mm 5 mm. A was also conducted to determine digestibility performance coppices commercial feed pellets. Nitrogen content varied among sprout sizes. The larger had highest nitrogen content, but acid detergent fibre, neutral fibre...

Abstract Impacts of large herbivores (>5 kg) on woody plants in A frican savannas are potentially most severe among shorter than 1.6 m. It is well established that browsing leads to longer shoots, yet prevents saplings from recruiting into adult size‐classes savannas. Increased shoot length, indicating faster growth, often associated with reduced concentrations tannins and increased nutrient concentrations, suggesting carbon limitation. We hypothesized that, average, suppress stem height...

This paper reports on diet selection of goats offered six browse species (i.e. Acacia natalitia [Vachellia natalitia], nilotica nilotica], Dichrostachys cinerea, Grewia occidentalis, Gymnosporia maranguensis and Scutia myrtina) commonly found in moist Zululand thornveld. The hypotheses tested were: (1) plant season affect selection, (2) physical traits such as leaf phenology, spinescence, shoot morphology size (3) is related to tannins, fibre protein ways that indicate nutrient maximisation....