Abstract
Although South African cycads are known to be declining in the wild, there is at present no broad-scale, quantitative analysis to support this view. In this study the fate of 626 individual cycads was assessed from 107 repeat photographs taken at 53 locations over three time-steps (broadly 1940s, mid-1990s and 2014). Of the cycads photographed in the 1940s, 78 % survived to the mid-1990s. By 2014, however, only 16 % of the original cycads remained. The Limpopo Province had the highest rate of cycad loss over the recorded period, followed by the Eastern Cape and KwaZulu-Natal. Gauteng and Mpumalanga had the lowest rate of cycad loss. In general, cycad losses were greatest on land under private ownership when compared to communal land and conservation areas. However, cycad loss as a result of damage sustained due to traditional medicine collection was highest on communal lands. Continued declines in most of the studied cycad populations are a concern due to the potential Allee effects this may introduce. While legislation to protect cycads is in place, enforcement is difficult given the spatially extensive and often remote and patchy distribution of cycad populations. Conservation approaches that work actively with farmers to protect cycads on their property, as well as education about sustainable traditional medicine collection practices in communal areas have the best chance of ensuring the viability of wild cycad populations.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Allee WC, Bowen E (1932) Studies in animal aggregations: mass protection against colloidal silver among goldfishes. J Exp Zool 61:185–207
Artabe A, Stevenson DW (1999) Fossil Cycadales in Argentina. Bot Rev 65:219–238
Bank H, Wink M, Vorster P, Treutlein J, Brand L, Bank M, Hurter J (2001) Allozyme and DNA sequence comparisons of nine species of Encephalartos (Zamiaceae). Biochem Syst Ecol 29:241–266
BGIS (2012) Vegetation map of South Africa, Lesotho and Swaziland (2012 beta and 2009). http://bgis.sanbi.org/vegmap/map2009_2012.asp. Accessed 19 Apr 2016
Butler JR, Barrett PM, Kenrick P, Penn MG (2009) Testing co-evolutionary hypotheses over geological timescale: interactions between Mesozoic non-avain dinosaurs and cycads. Biol Rev 84:73–89
Calonje M, Stevenson DW, Stanberg L (2016) The World List of Cycads, online edition [Internet]. 2013–2016. Accessed 19 July 2016
CITES (2015) Appendices. http://www.cites.org/eng/app/appendices.php. Accessed 19 Apr 2016
Courchamp F, Angulo E, Rivalan P, Hall RJ, Signoret L, Bull L, Meinard Y (2006) Rarity value and species extinction: the anthropogenic allee effect. PLoS Biol 4:e415. doi:10.1371/journal.pbio.0040415
Cousins SR (2012) The trade in South African Encephalartos species for traditional medicine: added pressure to the cycad extinction crisis. Encephalartos 107:39–43
Cousins SR, Williams VL, Witkowski ETF (2011) Quantifying the trade in cycads (Encephalartos species) in the traditional medicine markets of Johannesburg and Durban, South Africa. Econ Bot 65:356–370
Cousins SR, Williams VL, Witkowski ETF (2012) Uncovering the cycad taxa (Encephalartos species) traded for traditional medicine in Johannesburg and Durban, South Africa. S Afr J Bot 78:129–138
Cousins SR, Williams VL, Witkowski ETF (2013) Sifting through cycads: a guide to identifying the stem fragments of six South African medicinal Encephalartos species. S Afr J Bot 84:115–123
Crouch N (2006) Some esteemed muthi plants of the Zulu. Palmnut Post 9:16–17
Crouch NR, Smith GF, Lötter M, Symmonds R (2003) Encephalartos woodii - the first historically documented ethnomedicinal plant casualty in southern Africa. Encephalartos 73:25–28
Donaldson JS (2003) Cycads: status survey and conservation plan. IUCN/SSC Cycad Specialist Group, IUCN, Gland, Cambridge
Donaldson JS (2008) South African Encephalartos species. NDF Workshop Case Studies, WG 3—Succulents and Cycads, Case Study 4: Encephalartos, Mexico
Donaldson JS, Bösenberg JD (1999) Changes in the abundance of South African cycads during the 20th century: preliminary data from the study of matched photographs. In: Biology and Conservation of Cycads. In: Chen CJ (ed) Biology and conservation of cycads—proceedings of the fourth international conference on cycad biology (Panzhihua, China). International Academic Publishers, Beijing
Government Gazette (2013) 1 February 2013, Pretoria, vol. 572, No. 36117
Grobbelaar N (1999) Coning frequency, gender ratio and pollination of Encephalartos transvenosus (Zamiaceae) at the Modjadji Nature Reserve, and the germination of this cycad’s seed. In: Chen CJ (ed) Biology and conservation of cycads—proceedings of the fourth international conference on cycad biology (Panzhihua, China). International Academic Publishers, Beijing
Hoffman MT, Rohde RF (2011) Rivers through time: historical changes in the riparian vegetation of the semi-arid, winter rainfall region of South Africa in response to climate and land use. J Hist Biol 44:59–80
IUCN (2010) The IUCN red list of threatened species: plants. http://www.iucnredlist.org. Accessed 25 July 2016
IUCN (2012) The IUCN red list of threatened species: Encephalartos species. http://www.iucnredlist.org. Accessed 19 Apr 2016
Nagalingum NS, Marshall CR, Quental TB, Rai HS, Little DP, Mathews S (2011) Recent synchronous radiation of a living fossil. Science 334:796–799
Norstog KJ, Nicholls TJ (1997) The biology of the cycads. Cornell University Press, Ithaca
Pillay D (2015) Leading Jansenville farmer held after cycad bust. Herald. 24 Feb 2015
Raimondo DC, Donaldson JS (2003) Responses of cycads with different life histories to the impact of plant collecting: simulation models to determine important life history stages and population recovery times. Biol Conserv 111:345–358
Raimondo DC, von Staden L, Foden W, Victor JE, Helme NA, Turner RC, Kamundi DA, Manyama PA (2009). (Eds). Red List of South African Plants. Strelitzia 25, South African National Biodiversity Institute, Pretoria
Ravele AM, Makhado RA (2009) Exploitation of Encephalartos transvenosus outside and inside Mphaphuli Cycads Nature Reserve, Limpopo Province, South Africa. Afr J Ecol 48:105–110
Retief K, West AG, Pfab MF (2014) Can stable isotopes and radiacarbon dating provide a forensic solution for curbing illegal harvesting of threatened cycads? J Forensic Sci 59:1541–1551
Rousseau P (2012) A molecular systematic study of the African endemic cycads. Dissertation, University of Johannesburg
Yeld J (2014) Cycad thieves strike again. IOL: SCITECH/SCINCE/ENVIRONMENT/07. Aug 2014
Yessoufou K, Bamigboye SO, Daru BH, van der Bank M (2014) Evidence of constant diversification punctuated by a mass extinction in the African cycads. Ecol Evol 4:50–58
Acknowledgments
We are indebted to all provincial and local environmental officers for facilitating many landowners’ contacts details and required permits. Thank you to all landowners for allowing us to take the repeat photo in their property, and assisting us in locating the photo locality. The Mazda Wildlife Fund is acknowledged for the use of a courtesy vehicle. Thank you to the South African National Biodiversity Institute for funding the project.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by Daniel Sanchez Mata.
Appendix
Appendix
Typical examples of cycads used to establish 7 size classes. Seedlings fell into size classes 1 and 2, and were based on the number of compound leaves. Adult size classes 3–7 where based on stem height.
Rights and permissions
About this article
Cite this article
Okubamichael, D.Y., Jack, S., De Wet Bösenberg, J. et al. Repeat photography confirms alarming decline in South African cycads. Biodivers Conserv 25, 2153–2170 (2016). https://doi.org/10.1007/s10531-016-1183-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10531-016-1183-x