SAAB Webinar Recordings – 2022

Webinar 1: Prof. Brian Huntley (SAAB Gold medalist 2022)

Strategic Opportunism for Success in Biodiversity Programmes: Lessons Learned from Pragmatic Approaches in Southern Africa.

Abstract:

Conventional studies and training offered by universities provide very limited preparation for the real world of a professional career in botany and conservation biology. This talk will draw on over fifty years of experience as a botanist, project developer and institutional transformer in several southern African countries, and in ecosystems ranging from the Subantarctic tundra to the Congo rain forests. The period covered spans the years of Portuguese colonial administration of Angola, South Africa’s isolation during the era of grand Apartheid, to the great leap forward of the Mandela years. The emergence and growth of South Africa’s leadership in botany, terrestrial ecology and biodiversity conservation that occurred during challenging and ever-changing socio-political conditions demonstrates the ever-present opportunities available to young biologists, even during difficult times.

Webinar: Prof Brian Huntley
Webinar: Prof Brian Huntley, Question and Answer session

Webinar 2: Prof Ed Witkowski (SAAB Silver medalist 2022)

Studies of threatened plants species in “northern South Africa”

Abstract:

Since 1994, I (we) have undertaken studies, mainly with post-graduate students, on numerous threatened plant species in South Africa. This follows good experiences undertaking such studies on Banksia spp. in Western Australia. It started with a road trip looking at numerous threatened species in the old Transvaal. The endangered (EN) Euphorbia barnardii (1994), Haworthia koelmaniorum (1995/6), and the Critically Endangered (CR) Euphorbia clivicola (1996/7) were the initial studies. A more challenging study started in 1997, which continues to this day, on the CR Protea roupelliae ssp. hamiltonii (“a Protea story”). A theme with some of these studies is previously monitored declines in numbers, but a general lack of, or ineffective, action to stem the declines. The way fire is managed has also been shown to be critical for many of them. These studies were followed by Kniphofia umbrina (CR) in Swaziland (Eswatini), Ceropegia decidua subsp. pretoriensis (CR), Adenium swazicum (CR), six Delosperma spp. (mesems, two EN, 4 CR). Aloe spp., particularly A. peglerae (focus on pollination), and Kumara (Aloe) plicatilis (Western Cape), became a new focus beyond 2000, with a particular interest in pollination.  These were followed by KZN and Eastern Cape succulent Euphorbia species, E. umfoloziensis (Extinct in the wild?), and E. bupleurifolia, a “common species” becoming uncommon at a rapid rate.  Illegal harvesting of small succulent plants from the wild and trade have been problematic for many years. Indigenous medicinal plant species have also been a focus throughout. Finally, studies on protected tree species, such as marula, baobab and the pepperbark tree have been undertaken and continue. 

SAAB Webinar: Prof Ed Witkowski

Webinar 3: Dr Daniel Zhigila (SAAB Bronze Medalist 2022)

Systematics and extinction risk patterns in Thesium (Santalaceae)

Abstract:

Recent phylogenetic studies circumscribed the genus Thesium as monophyletic by including four segregate genera: Austroamericium, Chrysothesium, Kunkeliella and Thesidium. Additionally, the Greater Cape Floristic Region (GCFR) Thesium, having both ecological specialists and generalists, typifies an appropriate system for evaluating both the correlates of range extent and specialization, and the relative extinction risks associated with both. For my PhD, we tested the monophyly of the genus Thesium and its infrageneric taxa using expanded taxon sampling and phylogenetic analyses. One of the key objectives is to develop a well-resolved phylogeny that will allow a piece-wise revision of complex clades. Further, we tested the hypothesis that range size, ecological specialization and extinction risks are phylogenetically structured and then asked whether these will impact Thesium phylogenetic diversity. For the later, we quantified and modelled the niche breadth for each species based on the contemporary geographic range extents and ecological specializations. Key novelties include: i) establishment of an infrageneric classification scheme based on an integrative approach for the genus. This classification recognized five monophyletic subgenera, reflecting evolutionary relatedness and each supported by unambiguous morphological characters; ii) a detailed taxonomic revision for the T. subgenus Hagnothesium, comprising eight species which are all endemic to the Cape Region; iii)  discovery and description of eight species new to science, the majority of which are restricted to the highly fragmented agricultural landscape in the Agulhas Plain; iv) our data suggest a strong positive correlation between environmental variables and species range extents. However, the range extent, ecological specializations and extinction risk are phylogenetically random; and iv) the conservation status of the Cape Thesium was provided to aid in developing conservation strategies in the face of accelerated climate change.