The alpine flora on inselberg summits in the Maloti–Drakensberg Park, KwaZulu-Natal, South Africa

Abstract

Background: Inselberg summits adjacent to the Maloti–Drakensberg escarpment occupy an alpine zone within the Drakensberg Alpine Centre (DAC). Inselbergs, the escarpment and surrounding mountains such as Platberg experience a severe climate; inselberg summits are distinct by being protected from human disturbance.Objectives: The aim of this article was to describe for the first time the flora of inselberg summits and to assess their potential contribution to conservation of DAC plant diversity.Method: We investigated whether the flora of inselberg summits formed a representative subset of the DAC flora in terms of shared, especially endemic or near endemic, species and representation of families. All species were listed for six inselbergs between Giant’s Castle and Sentinel, located in the Royal Natal National Park (RNNP) during November 2005. Comparisons, using literature, were made with floras of the DAC, as well as Platberg, an inselberg approximately 60 km north from Sentinel in the RNNP.Results: We recorded 200 species of pteridophytes and angiosperms on inselbergs, 114 DAC endemics or near endemics, one possible new species, and several range and altitudinal extensions. Asteraceae, Poaceae and Ericaceae comprised 42.1% of endemic and near endemic species, with Scrophulariaceae and Hyacinthaceae contributing 8.8%. Inselberg and DAC floras differed in respective rankings of Crassulaceae (8th vs. 15th), Polygalaceae, Apiaceae and Rosaceae (10th, 11th, 12th vs. 15th), Poaceae (2nd vs. 5th), Cyperaceae (3rd vs. 4th) and Scrophulariaceae (6th vs. 2nd). Growth forms on inselbergs were consistent with DAC flora. Inselbergs shared 40% of species with Platberg.Conclusion: Inselbergs, which supported 7.9% of species occurring in the DAC flora, are well protected from human impact, lack alien plants, but, despite this, are highly vulnerable to climate change. Conservation importance of inselbergs will increase as escarpment vegetation becomes increasingly degraded as a consequence of intensifying land use.

Assessment of alpine summit flora in Kashmir Himalaya and its implications for long-term monitoring of climate change impacts

“…The present study observed a monotonic increase of narrow-endemic species with elevation, while as broad and non-endemic species decreased. A similar trend was observed by other researchers as well (Trigas et al 2013;Mráz et al 2016;Steinbauer et al 2016;Brand et al 2019). This pattern could be explained by two processes.…”

“…The present study observed a relatively disproportional dominance of species belonging to few families in the summit flora, rather than having a fair share of representation by many families. In this study, Asteraceae, Lamiaceae, and Ranunculaceae were the most dominant families, which go in line with the results of floristic studies in the same region (Dhar and Kachroo 1983;Dvorský et al 2011) or elsewhere (Rundel 2011;Shaheen et al 2015;Brand et al 2019). Since alpine regions possess extreme environmental conditions and high habitat heterogeneity (Körner 2016), it is likely that the plant species belonging to these families as adapted to a wide range of environmental conditions.…”

“…The proportion of geophytes and therophytes showed a gradual increase with elevation, while phanerophytes declined with elevation, and chamaephytes keep a low but constant share up to the highest summit. Similar trend and dominance of hemicryptophytes in alpine regions have been reported from the neighbouring mountains in Central Asia, such as Hindukush (Agakhanyantz and Breckle 1995), North-West Himalaya (Dickoré and Nüsser 2000;Dvorský et al 2011;Vashistha et al 2011), or elsewhere in the world, such as Inselberg summits in South Africa (Brand et al, 2019) and Swiss Alps (Matteodo et al 2013). The plant growth form of alpine regions is commonly ascribed to the temperature regime of the coldest period (Körner 2003;Körner 2011).…”

“…We observed a high proportion of perennials compared to annuals and biennials. The relative dominance of perennials in the summit flora of Kashmir Himalaya is typical of other alpine floras worldwide (Billings 1974;Dvorský et al 2011;Rundel 2011;Brand et al 2019). Perennial plant species have the characteristic of maintaining large proportions of total biomass belowground where they play an important role in carbohydrate storage over the prolonged severe winter months in alpines (Billings 1974;Körner 2003).…”

Festuca drakensbergensis (Poaceae): A common new species in the F. caprina complex from the Drakensberg Mountain Centre of Floristic Endemism, southern Africa, with key and notes on taxa in the complex including the overlooked F. exaristata

“… Carbutt’s (2019) Drakensberg Mountain Centre of Floristic Diversity and Endemism ( DMC ) includes the only alpine region in mainland Africa south of Mount Kilimanjaro ( Killick 1978 ), with a 2900 km disjunction. The DMC , covering some 40,000 km 2 , comprises a montane sub-centre, dominated by C 4 grass species and an alpine sub-centre [the former Drakensberg Alpine Centre of van Wyk and Smith (2001) and Carbutt and Edwards (2004 , 2006 )] dominated by C 3 grass species ( Brand et al 2019 ). The DMC is renowned for its high levels of plant diversity and endemism, hosting 227 endemic angiosperm species that account for ca.…”