The distribution and utilisation of Sclerocarya birrea (A Rich.) Hochst., subspecies caffra (Sond) in Vhembe District, Limpopo Province, South Africa

Abstract

Ruminants are major emitters of methane gas into the atmosphere thereby contributing to global warming. In an effort to find agents that can reduce ruminant gas emission and increase fodder digestion, plant material is being investigated. In a bioassay using ruminant faecal inoculum, the crude methanolic leaf extract of Helinus integrifolius was found to reduce gas emission at a concentration of 8.0 mg/ml. However, at this concentration fodder digestion is also reduced by 19% over a twenty four hour period and by 36% over a ninety six hour period. The sugar content of the digestate increased seven-fold and five-fold over 24 and 96 h respectively. Total phenolic content of the digestate increased 2.1 times and 1.3 times over 24 and 96 h respectively. At lower extract concentration gas emission is induced suggesting activation of microbiota. Hence, at higher concentrations gas emission is substantially decreased. The results suggest that while gas emission is reduced by addition of the extract the breakdown of cell wall material resulting in the release of sugars and phenolics is not. On the other hand, utilisation of the sugars by the ruminant flora might be substantially inhibited, since the overall digestion is reduced at this concentration of the extract.The distribution and utilisation of Sclerocarya birrea (A Rich.) Hochst., subspecies caffra (Sond) in Vhembe District, Limpopo Province, South Africa

Marula (Sclerocarya birrea subsp. caffra, Anacardiaceae) thrives under climate change in sub‐Saharan Africa

“…Modelling in this study estimates the actual suitable habitat of the subspecies. Results show that the predicted suitable habitat includes almost all locations where the species has been observed, sampled or known to occur (Maroyi, 2013, 2014; Mocheki et al, 2018; Muok et al, 2007). The suitable habitat of marula shows a predominant distribution in mopane and drier Zambezian miombo woodlands, predominantly in the low‐lying areas of southern Africa.…”

“…Marula grows successfully in relatively hot and dry environments (19–35°C, 200–1600 mm) (Mocheki et al, 2018; Orwa et al, 2009). In southern Africa, from 2080 to 2099, temperatures are expected to increase by an average of 3.4°C while rainfall is forecasted to decrease by a median of −4% (Carter & Parker, 2009).…”

“…Marula thrives in relatively high temperatures of 19–35°C and dry environments which receive about 200–1600 mm of rainfall per year (Mocheki et al, 2018; Orwa et al, 2009). The subspecies occurs at low altitude with sporadic individuals located as high as 1 800 m (Shackleton et al, 2002).…”

“…Marula plays important ecological and economic roles in its natural range. The wood is used for woodcarving, medicinal extracts are obtained from the bark, and leaves are browsed by several wild animals (Maroyi, 2013; Mocheki et al, 2018; Mojeremane & Tshwenyane, 2004; Shackleton et al, 2002). The subspecies is heavily logged in unprotected forests for firewood.…”

“…Probably, the most important organ is the fruit, whose pulp is commercially used to produce an internationally acclaimed alcoholic wine, the Amarula cream (Mojeremane & Tshwenyane, 2004). Honeybees are the major marula pollinators and seeds are dispersed by humans, elephants, kudu, wild pigs, zebra, baboons and other animals (Hall et al, 2002; Midgley et al, 2012; Mocheki et al, 2018; Setlalekgomo & Setlalekgomo, 2013). Because seeds are dispersed by animals, establishment of the subspecies is linked to suitability of the new habitat to the animals.…”