Bothalia - African Biodiversity & Conservation

Restoration of diversity and regeneration of woody species through area exclosure: the case of Maun International Airport in northern Botswana

BACKGROUND AND OBJECTIVES: Deforested and degraded areas can be cheaply and conveniently restored through establishment of exclosures. An area exclosure excludes animals and humans from accessing an area to promote natural regeneration of plants and rehabilitate ecological condition of the area. The study was aimed at: (1) determining the diversity (species richness, diversity and evenness); (2) assessing the stand structure (densities); and (3) assessing regeneration status of woody species inside and outside exclosed Maun International Airport, northern Botswana METHODS: Vegetation sampling was conducted from April to May 2018. A total of 48 and 37 quadrats of 20 x 20 m were laid down at 50 m intervals along transect lines inside and outside Maun International Airport, respectively. Identity, number of all live individuals and height of all woody species were recorded in all the quadrats. The diversity of all woody species was analysed by using the Shannon Diversity Index (H') and regeneration status of each woody species was assessed using frequency distribution of height class RESULTS: The diversity, evenness and species richness were significantly higher inside than outside Maun International Airport. Colophospermum mopane was the most abundant species both inside (75% of all woody species) and outside (96% of all woody species) Maun International Airport. More species showed more regeneration inside than outside Maun International Airport. The inside of Maun International Airport recorded more alien invasive woody species compared with the outside, owing to its original use as a residential area. The local communities might have introduced these species as ornamental trees CONCLUSION: This study, while limited in scale, contributes to understanding of the role of exclosures in enhancing woody species richness, diversity and evenness as well as facilitating regeneration of woody species. Degraded woodlands and other similar ecosystems could be cheaply and conveniently restored through establishment of exclosures, but more research and monitoring are required to fully understand the processes and impacts

**First record of Amaranthus crassipes subsp. warnockii (I.M.Johnst.) N.Bayón (Amaranthaceae) outside of the Americas, with nomenclatural notes**

BACKGROUND: The genus Amaranthus is taxonomically complex because of its high morphological variability, which led to nomenclatural confusion, misapplication of names and misidentifications. Unfortunately, floristic and taxonomic studies on this genus are still incomplete. A population of Amaranthus crassipes subsp. warnockii was discovered in Monastir Governorate, Tunisia, representing the first record for both the Tunisian and the African floras, as well as the first one outside of its American native distribution area OBJECTIVES: The main aim of the present study was to record Amaranthus crassipes subsp. warnockii (I.M.Johnst.) N.Bayón in Tunisia and Africa for the first time. Morphological characters and ecological data were provided. Clarification about the typification of the names Amaranthus crassipes, A. warnockii and Scleropus amaranthoides was also presented METHODS: The work was based on field surveys, analysis of relevant literature and examination of specimens preserved in the herbaria GH, HAL, P RO, NY, US and the Herbarium of the Faculty of Pharmacy of Monastir (Monastir University RESULTS: Nomenclatural notes were provided for Schlechtendal's A. crassipes (lec-totype at HAL, designated by Henrickson in 1999 but here corrected according to Art. 9.10 of the ICN); Schrader's Scleropus amaranthoides [a superfluous and illegitimate name (Arts. 52.1 and 52.2 of the ICN) and regarded as a homotypic synonym of A. crassipes s.str.]; and Moquin-Tandon's Scleropus amaranthoides [an invalid name (Art. 36.1a of the ICN CONCLUSION: Amaranthus crassipes subsp. warnockii is an alien species in Tunisia, growing in human-made habitat on clayey and sandy substrates within ruder-al vegetation where it can be considered a casual. We hope that in the future continuous monitoring of the population will take place, to verify the possible naturalisation and spread of this taxon in Tunisia. If the latter happens, actions for eradication of the plants are needed

**The new combination Coleus leemannii (N.H.Hahn) A.J.Paton for Rabdosiella leemannii N.Hahn (Lamiaceae: Nepetoideae: Ocimeae)**

The new combination Coleus leemannii (N.Hahn) A.J.Paton is provided for Rabdosiella leemannii N.Hahn (Lamiaceae: Ocimeae) from South Africa, a species that was overlooked in the recent synopsis of subtribe Plectranthinae.

A Critically Endangered Proteaceae in the Cape Florisitic Region threatened by an invasive pathogen

BACKGROUND: Sorocephalus imbricatus (Thunb.) R.Br. is a range-restricted species endemic to the Cape Floristic Region (CFR), South Africa. It is currently classified as Critically Endangered in accordance with the IUCN criteria. Like many other species endemic to the CFR, S. imbricatus is subjected to several major threats including habitat loss, habitat degradation and the impacts of invasive alien species. Sorocephalus imbricatus was recently identified as a species requiring improved representation in ex-situ collections. During field work undertaken to collect germplasm for this purpose, a concerning number of dead and dying plants were observed. OBJECTIVES: To determine the cause of rapid death of individuals in a remnant subpopulation of S. imbricatus. METHOD: A field visit to a subpopulation of the only extant population, Elands-kloof, was conducted to examine the symptoms associated with S. imbricatus mortality, and to collect samples for isolation and identification of putative pathogens. RESULTS: Dead and dying plants showed clear symptoms of root and collar rot, with Phytophthora cinnamomi Rands recovered from all samples. The collections highlighted the severe impact of P. cinnamomi on S. imbricatus, with the size of the subpopulation being reduced from 62 to 37 individuals (a 40% reduction) between October 2021 and May 2022. CONCLUSION: This study describes, for the first time, rapid mortality of the Critically Endangered Proteaceae species, S. imbricatus, likely caused by the invasive pathogen P. cinnamomi. This concerning discovery highlights the urgent need for greater recognition of the threat P. cinnamomi poses not only to S. imbricatus, but to the broader floristic diversity of the CFR. Importantly, it illustrates a need for a substantial body of work to be undertaken to address a significant lack of knowledge regarding the relative threat that P. cinnamomi poses to species of the CFR.

**A nomenclatural correction in Colchicum L. (Colchicaceae: Colchiceae) in southern Africa: two new combinations for C. coloratum J.C.Manning & Vinn., nom. superfl.**

The new combinations Colchicum burchellii (Baker) J.C.Manning & Vinn. and C. burchellii subsp. pulchrum (Schltr. & K.Krause) J.C.Manning & Vinn. are provided for the taxa currently known respectively under the names C. coloratum subsp. burchellii (Baker) J.C.Manning & Vinn. and C. coloratum J.C.Manning & Vinn., nom superfl.

**First record of the North African Launaea arborescens in southern Africa**

The first record of the non-native, naturalised Launaea arborescens (Batt.) Murb. in the Namib Desert raised questions of its origin and whether or not it could pose a threat to the indigenous vegetation. The North African plant was introduced in a forestry nursery in the Kuiseb Delta, and some individuals were also planted outside the nursery in the early 1970s. They have maintained a likely viable population for nearly 50 years but have so far not been observed elsewhere and thus appear not to be spreading.

**Evolutionary patterns in South African brambles (Rubus L.) - new insights from molecular markers**

BACKGROUND: South African brambles (Rubus L., Rosaceae) represent a complex group of six native species and at least 12 introduced taxa with different ploidy levels and varying tendencies to hybridisation. The role of hybridisation, intro-gression and apomixis in the ongoing evolution has been hypothesised based on morphological observations, but it has not been rigorously studied to date, and nor has the phylogeny of the group. OBJECTIVES AND METHODS: This paper aims to reveal the evolutionary patterns and mechanisms in South African brambles by employing three types of molecular markers: plastid and nuclear ribosomal DNA sequences, and nuclear micro-satellites. RESULTS: The data confirmed the tetraploid R. thaumasius A.Beek and diploid R. ludwigii Eckl. & Zeyh. as distinct native species, while the other four native species are shown to be closely related and likely derived from three ancestors. CONCLUSION: Ancient hybridisation and limited gene flow between regions (particularly between winter- and summer-rainfall zones) appear to be the main drivers of current patterns in the tetraploid R. pinnatus Willd. and hexaploid R. rigi-dus Sm. Current hybridisation is also likely, although rare. The mechanism of 'octoploid bridge' is proposed, which overcomes the ploidy reproduction barrier between R. pinnatus (or other tetraploids) and R. rigidus. No gene flow was detected between native and alien taxa, but clonal duplications were discovered in the R. bergii x pinnatus hybrid, which implies the possibility of apomictic spread of homoploid hybrids formed between native and introduced brambles and the potential for a new invasion. On the other hand, heteroploid hybrids (R. bergii x rigidus) are formed recurrently and spread only vegetatively.

**The relationship between mammalian burrow abundance and bankrupt bush (Seriphium plumosum) encroachment**

BACKGROUND: Much of the Grassland Biome in South Africa is prone to shrub encroachment, leading to loss of ecosystem services, habitat heterogeneity and species diversity. Burrowing mammals are an important component of grasslands as these animals create microhabitats for other taxa, including smaller mammal species, birds, reptiles and invertebrates. However, our understanding of how shrub encroachment affects burrowing mammals is poor OBJECTIVES: Here we assessed the relationship between burrow abundance and bankrupt bush, Seriphium plumosum, encroachment as well as burrowing mammal diversity in bankrupt bush encroached and non-encroached grasslands METHOD: Shrub density, medium and large mammal burrow abundance and density were measured in 24 encroached and 24 non-encroached areas randomly selected in the Telperion Nature Reserve, Mpumalanga, South Africa. In addition, burrowing mammal diversity was assessed using camera traps in a subset of six encroached and six non-encroached areas RESULTS: Our results show that the abundance and density of medium and large burrows were significantly lower in encroached areas than in non-encroached areas (p = 0.011 and p < 0.001, respectively). The relationship between burrow abundance and bankrupt bush encroachment was negative (rho = -0.456, p = 0.001). However, burrowing mammal diversity had no significant difference between encroached and non-encroached areas CONCLUSION: Our data, therefore, suggest that with increasing bankrupt bush encroachment and a decreased abundance in burrowing mammal ecosystem services, a negative effect will occur on burrowing mammal communities, leading to the reduction in species-specific habitat heterogeneity and possibly animal biodiversity

Urban intensity and flower community structure drive monkey beetle assemblage in Cape Town

BACKGROUND: Urban landscapes present an important opportunity for pollinator conservation, but little is known about the status and distribution of pollinator populations in urban habitats in Africa. This represents a major gap in the development of a global understanding of urban pollinators - particularly from the rapidly urbanising context. This study uses a speciose clade of flower-visiting beetles (Coleoptera: Scarabaeidae: Hopliini) to explore patterns of pollinator distribution in a major metropolitan area in South Africa OBJECTIVES: We investigated community composition across gradients of urban intensity (defined according to the percentage of soil-sealing within 1 km² of each sampling location) and socio-economic status to determine pollinator responses to these urban landscape effects METHODS: A selection of 142 sites were surveyed twice in the austral spring seasons of 2018 and 2019. Data were collected on habitat structure, flower diversity, and pollinator diversity RESULTS: The study found that different feeding guilds of monkey beetles favoured different levels of urban intensity and that beetle richness significantly correlated with flower richness. It did not, however, correlate with diversity indicating that abundance is less impacted than the number of species present. Monkey beetles with moderate sensitivity to urban intensity benefitted from the presence of preferred species of flowers CONCLUSION: Overall, the findings demonstrate the importance of plant community assemblage in supporting urban monkey beetles. We recommend landscaping with preferred flower species in urban parks to support urban pollinators

**A new species of Thilachium (Capparaceae) from the Analanjirofo Region, Madagascar**

Madagascar is a centre of speciation for the genus Thilachium Lour., which includes several species of small trees and shrubs occurring in a wide range of habitats. A new species of Thilachium, T. latifolium Fici, from the Analanjirofo Region of northeastern Madagascar is here described and illustrated. It is characterised by 1-foliolate leaves, leaf blades widely ovate or elliptic with shortly acuminate or acute apices, flowers in terminal, dense subumbels or corymbs, short pedicels and ellipsoid, ribbed fruit. The new species is related to T. madagascariense Fici, a species recently described from eastern Madagascar, differing in the wider, coriaceous leaves with shorter, mucronulate tip, flowers in terminal, 7-16-flowered subumbels or corymbs, shorter pedicels and longer anthers. The distribution, autecology and affinities of the new species are discussed, its conservation status is assessed, and an updated key is provided for the species of the genus Thilachium known from Madagascar.

An online survey on user perceptions of natural science collections in South Africa

BACKGROUND: In South Africa, and globally, the value of natural science collections for scientific research is not widely recognised and has led to its marginalisa-tion, which in turn has resulted in low funding, staffing and use of the collections AIM AND OBJECTIVES: To this end, as part of the effort to increase understanding and appreciation of the collections, a cross-sectional web-based survey was administered to users of natural science collections (NSCs) in South Africa. The objectives of the study were to identify the perceived value of NSCs to the research community; perceived or experienced barriers in accessing NSCs and associated data for use in research; perceptions of NSCs' current performance in serving the needs of stakeholders; and how performance is judged and what the expectations are to improve future performance of NSCs to better serve the needs of stakeholders METHODS: The survey consisted of 26 questions, distributed by email to relevant researcher community mailing lists, and posted on relevant social media groups. The survey was completed by 131 respondents RESULTS AND CONCLUSION: The study indicated the overall perception of the importance of NSCs and their accessibility to the student and researcher community in South Africa and internationally to be extremely important to their research. Lack of funding for operations and staff impedes the ability of researchers and other users alike in using NSCs to optimise their research and contribute to issues of societal concern. A sustained commitment is required from NSC institutions to work together to solve various challenges, including improvement in serving stakeholder needs, which will in turn assist with demonstrating the value of NSCs to policymakers, in order to lobby for support and funding. Improved recognition of the importance of NSCs for research by the scientific community will assist NSCs in demonstrating their impact. Political priority should also be given to the long-term upkeep and ongoing assistance of institutional infrastructures