Saving Critically Endangered Peninsula Granite Fynbos from extinction at Tokai Park, Cape Town

ReStory narrators: Megan Smith, Dr Alanna Rebelo, Dr Tony Rebelo

Peninsula Granite Fynbos infested with wattle and pine on the slopes of Constantiaberg (Photo credit: Byron-Mahieu van der Linde)

Peninsula Granite Fynbos

Peninsula Granite Fynbos is wholly confined to the City of Cape Town and found only on the lower, more fertile slopes of Table Mountain on the Cape Peninsula. Peninsula Granite Fynbos is perhaps best symbolised on Table Mountain by the Silver Tree, but is also incredibly rich in plant species and contains nine endemic species, all threatened with extinction: Unistem Aristea (Critically Endangered), Granite Cape Flax (Critically Endangered), Crown-climbers Friend (Rare), Small-flowered doll-rose (Rare), Spreading Everfig (Vulnerable), and Bakoven Brightfig (Vulnerable). Peninsula Granite Fynbos was also the home of the Wynberg Conebush and Table Mountain Widow Reed, but these species have been wiped out as a result of housing and agricultural developments and are now extinct.

(Left) The icon of Table Mountain, the Silver Tree (photo credit: Nicola van Berkel), (Middle) the Granite Cape Flax (Critically Endangered) was thought to be extinct, but now resides only on the lower slopes of Lion’s Head (photo credit: Gigi Laidler); and (Right) the Crown-climbers Friend (Rare) is also another range restricted species with inconspicuous flowers only found in the Table Mountain National Park (photo credit: Magriet Brink)

Unfortunately, over half of the natural extent of this rare Fynbos type is already transformed by agriculture, urbanisation and silviculture. Owing to failure to meet the national conservation target of 30%, Peninsula Granite Fynbos has recently been re-classified from Endangered to Critically Endangered. Much of the remaining fragments of Peninsula Granite Fynbos are either covered in pine plantations and infestations of Australian wattles or under threat of being destroyed by new vineyards. This makes invasive alien trees the biggest threat to Peninsula Granite Fynbos and the destruction for new vineyards a close second. Fast growing, alien invasive plants outcompete native Fynbos plants in the race for nutrients and light, and can alter soil properties, such as nitrogen levels and pH, in their favour. Fire suppression encourages these invasions as well as the encroachment of comparatively species-poor Afromontane forest into the species-rich Peninsula Granite Fynbos.

The upper Tokai Park section of Table Mountain National Park represents the most extensive area where Peninsula Granite Fynbos can be restored. However, much of upper Tokai Park is still under dense stands of wattles and pines, despite the last of the plantations having been removed in 2016. If these invasive alien trees – and similar stands at Cecilia and Newlands – were removed, then Peninsula Granite Fynbos would have a fighting chance and could be upgraded from ‘Critically Endangered’ to an ‘Endangered’ status. Since invasive alien trees have very few benefits to society, it is in our interest remove them and restore these priority areas.

(Left) The remaining Peninsula Granite Fynbos with the location of the Tokai Park section of Table Mountain National Park demarcated by a yellow point (map created by City of Cape Town and South African National Parks); (Right) A close-up of Upper Tokai Park, where the Peninsula Granite Fynbos is found. The extent of Peninsula Granite Fynbos at Tokai Park is indicated in yellow (map created by Alanna Rebelo)
(Left) The galls of the Australian Wattle (Acacia longifolia) biocontrol wasp in the foreground and a dense infestation of Wattle in the background, with some alien tree hackers bent to their task in between.  Some native Fynbos bulbs fight to find spaces to emerge (Middle) Bourbon Watsonia and (Right) Giant Capeblue (photo credit: Alanna Rebelo)

Restoration Efforts

There is an optimum strategy in terms of how restoration, in this case initially clearing invasive alien trees, should be carried out. Areas with low densities of alien invader plants have higher restoration potential and should be priority targeted for immediate clearing. It is also critical to get in early, as the longer infestations are left, the denser they become, and the more expensive to clear. Also, the longer the infestations are left, the less chance the recovering Fynbos has to recruit before the next fire.

Friends of Tokai Park and other hacking groups such as the Friends of Vlakkenberg and Silvermine, have mobilised volunteers to clear the alien invaders in upper Tokai Park from the high priority Fynbos areas. Working for Water teams have also cleared a large area of aliens, however the density and growth rates of the alien regeneration has been too large, and Fynbos is still being lost despite these efforts.

In addition to this mechanical restoration, which should allow species which still have seeds stored in the soils to recover, some additional restoration is needed. This includes addressing the recovery of plant species which do not have seeds in the soils. These are mostly the Sugarbushes (Protea sp.) and Conebushes (Leucadendron sp.), which keep their seeds in fire-proof cones in the canopy. Many cycles of plantation forestry result in the Protea overstory completely disappearing from Fynbos, and without plants there are no seed banks. We can bring these seeds back by sowing local Protea seeds after fires. Great care has to be taken not to mix populations. Table Mountain National Park Honorary Rangers have rescued Protea seeds from appropriate locations and sown them in the old plantation areas, with excellent recovery.

The only botanical assessments for Upper Tokai Park to date are those captured by citizen scientists on iNaturalist: over 410 indigenous plant species have already been recorded in upper Tokai Park, making the area remarkably species rich. Because there is no pristine Peninsula Granite Fynbos that has not been under plantations, the areas cleared by Friends of Tokai Park are the closest we have to knowing what this Fynbos may have looked like in its pristine state. Scientists need these references for setting restoration targets for the more heavily invaded areas.

(Left) The upper reaches of Tokai Park section of Table Mountain National Park invaded by Monterey Pine threating the indigenous vegetation; (Right) A group of volunteers from the Friends of Tokai Park clear alien wattles in a priority site of regenerating Peninsula Granite Fynbos (Photo credits: Friends of Tokai Park, Byron-Mahieu van der Linde)

The Friends of Tokai need volunteers (of all ages) to help remove alien species from the upper slopes of Tokai Park, and to upload observations onto iNaturalist of both indigenous and alien plants and animals. This will help in developing a comprehensive species list and distribution map for the area, and inform management plans and threatened species recovery plans. To either volunteer with or donate to this cause, contact the narrators.

During 2020, the Friends of Tokai Park will be launching an “Adopt-A-Plot” Project at Tokai Park, where community groups, families, clubs or companies can adopt a plot of Peninsula Granite Fynbos (difficulty depending on their level of fitness, experience etc.). If you live in or near the southern suburbs, please consider adopting a plot and supporting local conservation. Please check the website (launching soon) or Facebook page for more information, or e-mail tokaifynbosfriends@gmail.com to join our mailing list.

Volunteers (members of Friends of Tokai Park) clearing alien invader species in Upper Tokai Park (Photo credit: Friends of Tokai Park)

Further reading

Cape Town’s Unique Biodiversity and Endemic Ecosystems. Peninsula Granite Fynbos.

Cousins, S., Singels, E., Kraaij, T., 2018. Invasive alien plants in South Africa pose huge threats, but they can be stopped. The Conversation.

Rebelo, A.G., Holmes, P.M., Dorse, C., Wood, J. 2011. Impacts of urbanization in a biodiversity hotspot: Conservation challenges in Metropolitan Cape Town. South African Journal of Botany 77(1): 20-35.

Skowno, A.L., Poole, C.J., Raimondo, D.C., Sink, K.J., Van Deventer, H., Van Niekerk, L., Harris, L.R., Smith-Adao, L.B., Tolley, K.A., Zengeya, T.A., Foden, W.B., Midgley, G.F., Driver, A. 2019. National Biodiversity Assessment 2018: The status of South Africa’s ecosystems and biodiversity. Synthesis Report. South African National Biodiversity Institute, an entity of the Department of Environment, Forestry and Fisheries, Pretoria. pp. 1–214

Partners

  • Friends of Tokai Park
  • SANParks
  • SANParks Honorary Rangers
  • iNaturalist
  • Kirstenbosch Gardens
  • Millennium Seed Bank
  • Friends of Silvermine & Vlakkenberg

Funders

Donations and time from the public through Friends of Tokai Park and SANParks Honorary Rangers.

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