PlantLife Volume 58.3, December 2024. Flora of the Makuleke Concession, Northern Kruger National Park

 

Flora of the Makuleke Concession, Northern Kruger National Park

Text and images by Duncan McKenzie

 

In the far north-eastern corner of South Africa lies a botanical treasure that has until recently been relatively unexplored. The Makuleke wilderness area supports a diverse flora containing many taxa restricted to the Limpopo Valley (such as Barleria taitensis subsp. rogersii, Figure 1), and taxa from tropical East Africa as well as many Lowveld and Soutpansberg specials.

 

Figure 1 Barleria taitensis subsp. rogersii

 

INTRODUCTION

The Makuleke Concession, situated between the Luvuvhu and Limpopo Rivers in the far northern portion of the Kruger National Park (KNP) in the Limpopo Province of South Africa (Figure 2), is a culturally and historically significant corner of our country. With history dating back to the Middle Stone Age of 250 000 years ago through to San rock art sites from about 2000 years ago, the impressive iron-age civilisation at Thulamela in the mid-1400’s and to ivory traders at Crook’s Corner in the late 1800’s and early 1900’s, military occupation and then finally incorporation into the KNP.

Figure 2  Location map

The Concession, measuring approximately 24 000 ha in extent, belongs to the Makuleke Community, who were forcibly removed in 1968. After a lengthy process it was finally returned to the community in 1998 but is managed by the South African National Parks, falling under the Pafuri Section Ranger. The Concession is currently used for tourism and training purposes, with three concession holders that enjoy exclusive traversing rights.

BIOPHYSICAL ENVIRONMENT

Climate and Geology

The Makuleke borders on Zimbabwe and a small section of Mozambique, and the entire northern boundary along the Limpopo River is unfenced. It is situated in the lowest rainfall region of the KNP (250-300mm/ year), nearing semi-desert conditions. However, the two rivers bring life-sustaining moisture and the adjacent floodplain pans in the Concession have been awarded Ramsar Wetland status. Elevation varies from about 200 meters above mean sea level (mamsl) in the east at Crook’s Corner to 410 mamsl at Lanner Gorge, which is also the most famous landmark in the Concession (Figure 3). There are three major geological influences present, namely sandstone, basalt and broad alluvial floodplains.

 

Flora Overview

The Makuleke falls under the Mopane Bioregion of the Savanna Biome and contains no less than six nationally recognised vegetation types in eight broad but distinct vegetation communities (Figure 4). Of particular interest to botanists are the many species that either reach their southern-most distribution in Africa in the area or reach their western-most distribution limit here from coastal Mozambique or reach their eastern-most distribution limit from along the Soutpansberg. In addition, the Makuleke is home to many Limpopo Valley endemics, as well as species that are hard to find elsewhere in the country.

Figure 3 Lanner Gorge on the Luvuvhu River

Figure 4  Broad-scale vegetation communities represented in the Maluleke Concession

This diversity of geology, vegetation types as well as climate and geographical location has led to a fascinating diversity of flora. To date, over 640 plant species have been recorded from the Concession and no doubt many are still waiting to be discovered. That figure is an impressive one third of all the plant species recorded in the KNP, in only 1,2% of the surface area. The dominant plant family is Fabaceae with 77 species recorded to date, followed by Malvaceae and Poaceae with 56 each. Although only lying fourth with 39 taxa, the Acanthaceae family is particularly well represented, and this area is an acanth hotspot. The dominant families and genera recorded are presented in Table 1 below.

Table 1. Summary of dominant plant families and taxa in the Makuleke Concession

Botanising in the Makuleke is unfortunately not straightforward. Not only is the use of the Concession exclusive to the three concession holders and their guests or students (there is only one public road traversing it), as per SANParks rules general visitors may not leave their vehicles. Many large mammals are also resident, which further inhibits botanical exploration. Owing to this, as well as the previous military presence, the flora was mostly ‘hidden’ from the world except from a few early botanists who collected in the area in the mid-1900’s. Only relatively recently have a few botanical researchers begun to explore the area and, combined with several amateur botanists uploading images onto the online citizen science biodiversity database iNaturalist, we are truly beginning to understand the complexity and importance of the area from a botanical perspective. Most exploring is done on foot accompanied by qualified armed guides or instructors and is often combined with other activities such as birding and general tourism (Figure 5). 

Figure 5  Exploring the fever tree forest on foot

The author has been visiting the Makuleke since 2012 under the education banner, presenting courses for a leading guide training organisation. This has allowed for unlimited access to the Concession’s fascinating flora.

Vegetation Communities

Eight broad vegetation communities can be recognised within the Makuleke Concession (Figure 4). Representative photographs of some of these are displayed in Figure 6. Each one of these is briefly described here with selected flora highlights included.

Figure 6  Representative photographs of major habitat types in Maluleke

Top left: Cliffs and outcrops, Mutale River. Top right: Floodplain pan, Banyini Pan. Bottom left: Fever Tree Forest. Middle right: Sandveld. Bottom right: Floodplain grassland and riparian forest.

Mopane Woodland

General

The dominant vegetation community within the central portions of Makuleke is Mopane Colophospermum mopane Woodland. These abundant trees are found mostly on the basalts, where they grow as stunted shrubs on the plains and tall ‘cathedral’ type in the highest ridges and drainage lines. Despite the apparent abundance of mopane, this community is probably second only to the Outcrop Woodland/Sandveld community with regard to species diversity.

Flora

Additional canopy dominants are Kirkia acuminata and Adansonia digitata, while smaller trees include Terminalia prunioides, Gardenia resiniflua and Gymnosporia putterlickioides. Members of the Acanthaceae are particularly well represented and include Barleria quadriloba, B. ventricosa, B. virgula, Megalochlamys revoluta, Anisotes rogersii and Elytraria acaulis. Succulents include Stapelia kwebensis and S. gettliffei while interesting additional herbs are Cephalocroton mollis, Euphorbia tettensis and Hibiscus rhabdotospermus (Figure 7).

 

Figure 7  Selected flora species found in Mopane Woodland

Top row (l to r): Gymnosporia putterlickioides & Stapelia kwebensis

Middle row (l to r): Adansonia digitata, Stapelia gettliffei & Barleria ventricosa

Bottom row (l to r): Barleria quadriloba & Megalochlamys revoluta

Outcrop Woodland and Sandveld

General

The western sections of Makuleke contain impressive sandstone gorges, hills and outcrops that support a wide variety of localised plants and many succulents, while flatter areas in between contain deep sand and support a flora reminiscent of coastal Mozambique. The Luvuvhu and Mutale Rivers have carved out impressive gorges that host many species that are restricted to the far eastern Soutpansberg and adjacent Zimbabwe.

Flora

The rockier areas are dominated by large groves of Androstachys johnsonii, with a diverse supporting cast containing Ficus tettensis, Entandrophragma caudatum, Commiphora marlothii and Mimusops obtusifolia. Succulents are well represented and include Euphorbia aeruginosa, E. rowlandii, an isolated population of Australluma ubomboensis, Aloe excelsa, A. lutescens, the unique Huernia procumbens and Sansevieria hallii. Acanths are again diverse with Barleria matopensis, B. albostellata and Crabbea velutina all common. The attractive localised Ceratotheca saxicola is always a treat to find, as is Xerophyta pauciramosa which grows in small colonies in areas with shallow soils.

Areas of deep sand are characterised by a high diversity of trees such as Xeroderris stuhlmannii, Afzelia quanzensis, Terminalia myrtifolia, Terminalia sericea, Monodora junodii, Combretum collinum, Albizia forbesii, Strychnos potatorum and the wonderfully named Pseudolachnostylis maprouneifolia. Smaller shrubs include Hippocratea crenata, Maerua decumbens, Tricalysia junodii, Coptosperma zygoon and Phyllanthus pinnatus. The ground layer contains some real gems such as Harpagophytum zeyheri, Polygala marensis, Listia bainesii and the gorgeous Ammocharis tinneana. Some of these are presented in Figure 8.

Figure 8  Selected flora species found in Outcrop Woodland and Sandveld

Top Row (l to r): Ammocharis tinneana & Euphorbia aeruginosa.

Middle Row (l to r): Huernia procumbens, Ceratotheca saxicola & Barleria matopensis.

Bottom Row (l to r): Monodora junodii & Sansevieria hallii 

Palmveld and Floodplain Grassland

General

The wide grassy floodplains of the Limpopo River, and to a lesser degree the Luvuvhu River, support an interesting wetland vegetation assemblage. Although none of the more than 30 pans in the floodplain permanently holds water, they still support an interesting, if seasonal, flora. The drier parts of the floodplain support a very low diversity of plants, dominated by palms and tall grasses. 

Flora

When full for several consecutive months, the pans support an interesting blend of mostly tropical herbs such as Nymphaea lotus, Limnophyton obtusifolium and Neptunia oleracea. Pan edges contain some interesting herbs such as Jacquemontia ovalifolia, Cullen tomentosum and Rorippa micrantha. The drier parts of the floodplain are dominated by the robust grass Sporobolus consimilis as well as the two palms Phoenix reclinata, and in particular, tall specimens of Hyphaene petersiana (Figure 9).

Figure 9  Selected flora species found in Palmveld and Floodplain Grasslands

Top Row (l to r): Phoenix reclinata & Nymphaea lotus

Middle Row (l to r): Hyphaene petersiana, Limnophyton obtusifolium & Sporobolus consimilis

Bottom Row (l to r): Cullen tomentosum & Jacquemontia ovalifolia

Arid Thornveld

General

Growing in belts adjacent to the two major drainages and floodplains is the arid woodland community. This is a botanically depauperate area dominated by trees formally lumped in the Acacia genus, but nonetheless it still supports a few interesting taxa. Due to the fertile soils, this area is heavily utilised by herbivores and often contains bare soil.

Flora

The canopy is represented by a low diversity of species that include Vachellia tortilis, Senegalia senegal var. rostrata, Salvadora australis, S. persica, Boscia albitrunca, Balanites pedicellaris and Albizia anthelmintica. Shrubs include the spectacular and localised sunbird magnet Anisotes formosissimus and the plant with the sharpest thorns in the bush: Azima tetracantha. Smaller taxa include a host of Acanths such as Petalidium aromaticum, Barleria virgula and B. senensis as well as the showy duo of Indigofera holubii and Tribulus zeyheri (Figure 10).

Figure 10  Selected flora species found in Arid Thornveld

Top Row (l to r): Anisotes formosissimus & Salvadora persica

Middle Row (l to r): Senegalia senegal var. rostrata, Barleria senensis & Salvadora australis

Bottom Row (l to r): Petalidium aromaticum & Barleria virgula

Fever Tree Forest

General

This is a strikingly beautiful vegetation community but wholly dominated by a single species, namely Vachellia xanthophloea. It occurs in small to large groves adjacent to the two major drainages and probably acts as a pioneer community of sorts for the more diverse riparian forest community.

Flora

Tall specimens of Faidherbia albida are scattered throughout the Fever Tree Forest. Shrubs located in the understory include Thilachium africanum and Azima tetracantha, while the robust climber Capparis tomentosa occurs throughout. In places, particularly along the Luvuvhu River, the beautiful dwarf shrub Anisotes formosissimus grows in impressive numbers (Figure 11).

 

Figure 11  Selected flora species found in the Fever Tree Forest

Top row (l to r): Vachellia xanthophloea

Middle row (l to r): Vachellia xanthophloea, Vachellia xanthophloea and Capparis tomentosa

Bottom row (lto r): Thilachium africanum & Azima tetracantha

                 

 

Riparian Forest

General

Tall, evergreen forest occurs along both the Limpopo and Luvuvhu Rivers, lying between the riverbeds and the Fever Tree Forest or floodplain grasslands. The canopy is diverse and contains large specimens of familiar and widespread Lowveld trees. The dense understory is particularly spikey, and climbers of varying sizes are abundant.

Flora

The most frequently encountered canopy trees include Kigelia africana, Diospyros mespiliformis, Philenoptera violacea, Xanthocercis zambesiaca, Albizia versicolor, Faidherbia albida, Vachellia robusta subsp. clavigera, V. xanthophloea, Garcinia livingstonei, Trichilia emetica, Ficus sansibarica and F. sycomorus. The dense understory contains the shrubs Gymnosporia senegalensis, Azima tetracantha, Maclura africana, Senegalia schweinfurthii, Tabernaemontana elegans and Deinbollia xanthocarpa. Climbers range from delicate, such as Asystasia intrusa, Cynanchum mossambicense and Strophanthus kombe, to extremely robust, like Combretum miocrophyllum, Capparis tomentosa and Cocculus hirsutus. Acanths are again well represented on the ground layer, and include Justicia matammensis, Barleria elegans, Dicliptera verticillata and Hypoestes forskaolii. The delicate herb Jamesbrittenia micrantha occurs on the riverbanks (Figure 12).

Figure 12  Selected flora species found in Riparian forest

Top Row (l to r): Cynanchum mossambicense & Kigelia africana

Middle Row (l to r): Jamesbrittenia micrantha, Faidherbia albida & Albizia versicolor

Bottom Row (l to r): Combretum microphyllum & Ficus sansibarica

 

Riverbeds

General

The wide, sandy riverbed of the Limpopo River provides a vegetation community that is unique in several aspects. Not only is this area submerged for several months in the rain season, but it also becomes hyper arid in the dry. It is also the most northerly vegetation community in South Africa and one that has probably been overlooked as the plants are not always that obvious. Several species we have located here have been new records for South Africa (from tropical areas further north) or new for the Kruger National Park (from the arid western parts of southern Africa) or have not been recorded from within the Republic for decades. The lack of outright dominant species makes it difficult to formally classify but can probably best be described as sparse grassland. This is the easiest vegetation community to botanise in Makuleke as it can be done barefoot and in relative safety from large mammals!

Flora

Various graminoids dominate the elevated sandbars within the riverbed. These include Phragmites mauritianus, Echinochloa pyramidalis, Cyperus laevigatus and Fuirena ciliaris. Interesting and localised herbs include Lotus arabicus, Indigofera macrocarpa, Diclis petiolaris, Hermannia modesta, Sphaeranthus peduncularis, Vahlia capensis, Jamesbrittenia micrantha and Lepidium englerianum. Pluchea dioscoridis (or bojeri? Who knows?) occurs especially in the driest edges of this community (Figure 13).

Figure 13  Selected flora species found in Riverbeds

Top Row (l to r): Vahlia capensis & Indigofera macrocarpa

Middle Row (l to r): Diclis petiolaris, Hermannia modesta & Sphaeranthus peduncularis

Bottom Row (l to r): Lotus arabicus & Pluchea dioscoridis (or bojeri)

Conclusion

Unfortunately, more and more alien species are being recorded within the Concession, particularly along the Limpopo River where seeds enter from upstream areas (Pretoria and most of Johannesburg are even in the Limpopo catchment!). These include Calotropis procera, Nicotiana glauca and several Datura spp. These remain a threat especially to the riparian habitats.

Ongoing botanical exploration of Makuleke is likely to reveal additional species to the overall list, as well as new species for South Africa. Additionally, there are several undescribed or unresolved taxa that are awaiting formal description or resolution. As this area is managed by SANParks and collecting of plants is illegal, we do rely heavily on good quality photographs that are uploaded onto iNaturalist, and this practice is encouraged for all visitors and staff alike.

 

About the author:   Duncan is based in Nelspruit and is co-director of a consultancy called Digital Earth. He has performed biodiversity assessments throughout Africa, including in countries such as Mali, Morocco, Mozambique, Guinea, Sierra Leone, Tanzania and the Democratic Republic of the Congo. Duncan is currently the Mpumalanga Regional Co-ordinator and member of the Steering Committee for the Southern African Bird Atlas Project (2), a Trustee of the John Voelcker Bird Book Fund (Robert’s bird books), is the and lead author on the newly released Roberts Bird Guide Greater Kruger National Park and a member of the Mpumalanga-based Plant Specialist Group. Duncan has also presented more than 80 bird courses within the Kruger National Park, mostly up in the Makuleke Concession in the far north. He was awarded the Birdlife South Africa Owl Award in 2017 for his contribution to bird conservation. Duncan is a registered Ecologist with the South African Council for Natural Scientific Professions.