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Long-term growth patterns of Welwitschia mirabilis, a long-lived plant of the Namib Desert (including a bibliography)

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Abstract

Over the past 14 years, long-term ecological research (LTER) was conducted on the desert perennial, Welwitschia mirabilis (Gnetales: Welwitschiaceae), located in the Welwitschia Wash near Gobabeb in the Central Namib Desert. We measured leaf growth of 21 plants on a monthly basis and compared this with climatic data. The population structure as well as its spatial distribution was determined for 110 individuals. Growth rate was 0.37 mm day−1, but varied 22-fold within individuals, fluctuating seasonally and varying between years. Seasonal patterns were correlated with air humidity, while annual differences were affected by rainfall. During three years, growth rate quadrupled following episodic rainfall events >11 mm during mid-summer. One natural recruitment event followed a 13-mm rainfall at the end of summer. Fog did not appear to influence growth patterns and germination. Plant location affected growth rate; plants growing on the low banks, or ledges, of the main drainage channel grew at a higher rate, responded better and longer to rainfall and had relatively larger leaves than plants in the main channel or its tributaries. This could be due to better water and nutrient conditions on the ledges than elsewhere. The population appears to be growing outwards, with the smallest (youngest?) plants highest. Sex ratio was male-biased and males grew larger than females. Our study, in conjunction with the extensive literature base on Welwitschia, published here in a bibliography comprising 297 papers, indicates the knowledge gaps and needs for further ecological studies, including the continuation of our LTER programme. This should elucidate the reproductive output, seed dispersal, recruitment, water availability, age structure, and ecological differences between the sexes, and long-term life history strategies. Such knowledge would contribute to desert ecology and improve the management strategies of this unique Namib Desert perennial.

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References

  • Abrams, M. M., Jacobson, P. J., Jacobson, K. M. & Seely, M. K. 1997. Survey of soil chemical properties across a landscape in the Namib Desert. J. Arid Environ. 35: 29–38.

    Google Scholar 

  • Bornman, C. H. 1972. Welwitschia mirabilis: paradox of the Namib Desert. Endeavour 31(113): 95–99.

    Google Scholar 

  • Bornman, C. H. 1977. Welwitschia mirabilis: structural and functional anomalies. Madoqua (II) 10: 21–31.

    Google Scholar 

  • Bornman, C. H. 1978. Welwitschia: paradox of a parched paradise. C. Struik Publishers, Cape Town.

    Google Scholar 

  • Bornman, C. H., Botha, C. E. J. & Nash, L. J. 1973. Welwitschia mirabilis: observations on movement of water and assimilates under Föhn and fog conditions. Madoqua (II) 2: 25–31.

    Google Scholar 

  • Bornman, C. H., Elsworthy, J. A., Butler, V. & Botha, C. E. J. 1972. Welwitschia mirabilis: observations on general habit, seed, seedling and leaf characteristics. Madoqua (II) 1: 53–66.

    Google Scholar 

  • Brinckmann, E. & von Willert, D. J. 1987. Injury and recovery of Welwitschia mirabilis. Dinteria 19: 69–76.

    Google Scholar 

  • Bustard, L. 1990. The ugliest plant of the world: the story of Welwitschia mirabilis. Kew Magazine 7: 85–90.

    Google Scholar 

  • Butler, V. 1975. Ultrastructure of the germinating Welwitschia mirabilis seed. Ph.D. Thesis, University of Natal, Pietermaritzburg, South Africa.

    Google Scholar 

  • Butler, V., Bornman, C. H. & Evert, R. F. 1973. Welwitschia mirabilis: Vascularization of a one-year-old seedling. Bot. Gazette 134: 63–73.

    Google Scholar 

  • Carafa, A. M., Napolitano, G. & D'Acunzo, A. 1989. Welwitschia mirabilis Hook.: una strana pianta del deserto della Namibia. Natura e Montagna 36: 17–20.

    Google Scholar 

  • Charnov, E. L. & Bull, J. 1977. When is sex environmentally determined? Nature, London 266: 828–830.

    Google Scholar 

  • Cooper-Driver, G. A. 1994. Welwitschia mirabilis-a dream come true. Arnoldia 54(2): 2–10.

    Google Scholar 

  • Eller, B. M., von Willert, D. J., Brinckmann, E. & Baasch, R. 1983. Ecophysiological studies on Welwitschia mirabilis in the Namib desert. South Afr. J. Bot. 2: 209–223.

    Google Scholar 

  • Freeman, D. C., Klikoff, L. G. & Harper, K. T. 1976. Differential resource utilization by the sexes of dioecious plants. Science 193: 597–599.

    Google Scholar 

  • Giess, W. 1969. Welwitschia mirabilis Hook. fil. Dinteria 3: 3–55.

    Google Scholar 

  • Gut, S. 1988. Untersuchungen zum Feuchtehaushalt in den Dünen der zentralen Namib (Namibia/Südwestafrika). M.Sc. Thesis, University of Zürich, Switzerland.

    Google Scholar 

  • Henschel, J. R. 1998. International research cooperation with the Desert Research Foundation of Namibia (DRFN) benefits the natural environment in Namibia. Pp. 401–406. In: Alexander von Humboldt Foundation (ed.), Wissenschaftleraustausch und Entwicklungszusammenarbeit vor der Jahrtausendwende: Bestandaufnahme, Probleme und Perspektiven. Nomos, Baden-Baden, Germany.

    Google Scholar 

  • Henschel, J. R., Mtuleni, V., Gruntkowski, N., Seely, M. K. & Shanyengana, S. E. 1998. Namfog: Namibian Application of Fog-Collecting Systems, Phase I: Evaluation of Fog-Water Harvesting. Occasional Paper No.8, Desert Research Foundation of Namibia, Gobabeb, 62 pp.

    Google Scholar 

  • Herppich, W. B., Flach, B. M.-T., von Willert, D. J. & Herppich, M. 1996. Field investigations of photosynthetic activity, gas exchange and water potential at different leaf ages in Welwitschia mirabilis during a severe drought. Flora 191: 59–66.

    Google Scholar 

  • Herre, H. 1961. The age of Welwitschia bainesii (Hook. f) Carr.: C14 research. J. South Afr. Bot. 27: 139–140.

    Google Scholar 

  • Jacobson, K. M. 1997. Moisture and substrate stability determine VA-mycorrhizal fungal community distribution and structure in an arid grassland. J. Arid Environ. 35: 59–75.

    Google Scholar 

  • Jacobson, K. M., Jacobson, P. J. & Miller, O. K. 1993. The mycorrhizal status of Welwitschia mirabilis. Mycorrhiza 3: 13–17.

    Google Scholar 

  • Jürgens, N. 1993. Namib -die afrikanische Wüste der lebenden Wasserspeicher. Uni Hamburg Forschung 27: 68–76.

    Google Scholar 

  • Jürgens, N., Burke, A., Seely, M. K., & Jacobson, K. M. 1997. Desert. Pp. 189–214. In: Cowling, R. M., Richardson, D. M. & Pierce, S. M. (eds), Vegetation of Southern Africa. Cambridge University Press, Cambridge.

    Google Scholar 

  • Kers, L. E. 1967. The distribution of Welwitschia mirabilis Hook.f. Svensk Botanisk Tidskrift 61: 97–125.

    Google Scholar 

  • Kutschera, L., Lichtenegger, E., Sobotik, M. & Haas, D. 1997a. Die Wurzel, das neue Organ, ihre Bedeutung für das Leben von Welwitschia mirabilis und anderer Arten der Namib sowie von Arten angrenzender Gebiete, mit Erklärungen des geotropen Wachstums der Pflanzen. Pflanzensoziologisches Institut, Klagenfurt, Austria, 94 pp.

    Google Scholar 

  • Kutschera Mitter, L., Lichtenegger, E., Sobotik, M. & Haas, D. 1997b. Die Wurzel -Hilfe für das Ñberleben von Welwitschia mirabilis und anderer Arten der Namib. Palmengarten Frankfurt/Main 61(1): 31–40.

    Google Scholar 

  • Lancaster, J., Lancaster, N. & Seely, M. K. 1984. Climate of the central Namib Desert. Madoqua 14: 5–61.

    Google Scholar 

  • Loutit, B. D., Louw, G. N. & Seely, M. K. 1987. First approximation of food preference and the chemical composition of the diet of the desert-dwelling black rhinoceros, Diceros bicornis L. Madoqua 15: 35–41.

    Google Scholar 

  • Marsh, B. 1982. An ecological study of Welwitschia mirabilis and its satellite fauna. Namib Bull. 4: 3–4.

    Google Scholar 

  • Marsh, B. A. 1987. Micro-arthropods associated with Welwitschia mirabilis in the Namib Desert. South Afr. J. Zoology 22: 89–96.

    Google Scholar 

  • Marsh, B. A. 1990. The microenvironment associated with Welwitschia mirabilis in the Namib desert. Pp. 149–153. In: Seely, M.K. (ed.), Namib ecology: 25 years of Namib research. Transvaal Museum 7, Pretoria.

  • Massmann, U. 1976.Welwitschia: nach 90 Jahren. Namib und Meer 7: 45–46.

    Google Scholar 

  • Moisel, A. & Moll, E. J. 1981. A Braun-Blanquet survey of the vegetation of the Welwitschia Plain. Dinteria 15: 3–11.

    Google Scholar 

  • Muhammad, A. F. & Sattler, R. 1982. Vessel structure of Gnetum and the origin of angiosperms. Am. J. Bot. 69: 1004–1021.

    Google Scholar 

  • Olivier, J. 1995. Spatial distribution of fog in the Namib. J. Arid Environ. 29: 129–138.

    Google Scholar 

  • Rodin, R. 1958a. Leaf anatomy of Welwitschia. I. Early development of the leaf. Am. J. Bot. 45: 91–95.

    Google Scholar 

  • Rodin, R. J. 1958b. Leaf anatomy of Welwitschia. II. A study of mature leaves. Am. J. Bot. 45: 96–103.

    Google Scholar 

  • Schulze, E.-D., Eller, B. M., Thomas, D. A., von Willert, D. J. & Brinckmann, E. 1980. Leaf temperatures and energy balance of Welwitschia mirabilis in its natural habitat. Oecologia 44: 258–262.

    Google Scholar 

  • van Jaarsveld, E. 1990. The cultivation and care of Welwitschia mirabilis, the extraordinary caudiciform from the Namib desert. Aloe 27(3): 69–82.

    Google Scholar 

  • van Jaarsveld, E. 1992. Welwitschia mirabilis in cultivation at Kirstenbosch. Veld & Flora 12: 119–121.

    Google Scholar 

  • von Willert, D. J. 1993. Can Welwitschia mirabilis have more than only two foliage leaves? South Afr. J. Bot. 59: 639–640.

    Google Scholar 

  • von Willert, D. J. 1994. Welwitschia mirabilis Hook. fil. -das Ñberlebenswunder der Namibwüste. Naturwissenschaften 81: 430–442.

    Google Scholar 

  • von Willert, D. J., Eller, B. M., Brinckmann, E. & Baasch, R. 1982. CO2 gas exchange and transpiration of Welwitschia mirabilis Hook. fil. in the central Namib desert. Oecologia 55: 21–29.

    Google Scholar 

  • von Willert, D. J., Eller, B. M., Werger, M. J. A., Brinckmann, E. & Ihlenfeldt, H. H. 1992. Life strategies of succulents in deserts with special reference to the Namib Desert. Cambridge University Press, Cambridge.

    Google Scholar 

  • von Willert, D. J. & Wagner-Douglas, U. 1994. Water relations, CO2 exchange, water use efficiency and growth of Welwitschia mirabilis Hook. fil. in three contrasting habitats of the Namib Desert. Botanica Acta 107: 291–299.

    Google Scholar 

  • Wallace, C. S. & Rundel, P. W. 1979. Sexual dimorphism and resource allocation in male and female shrubs of Simmondsia chinensis. Oecologia 44: 34–39.

    Google Scholar 

  • Walter, H. 1936. Die ökologischen Verhältnisse in der Namib-Nebelwüste (Südwestafrika) unter Auswertung der Aufzeichnungen des Dr. G. Boss (Swakopmund). Jahrbuch Wissenschaftlichen Botanik 84: 58–221.

    Google Scholar 

  • Walter, H. 1971. The ecology of Welwitschia mirabilis. Pp. 369–374. In: Ecology of tropical and subtropical vegetation. Oliver & Boyd, Edinburgh, 539 pp.

    Google Scholar 

  • Walter, H. & Breckle, S.-W. 1984. Die Ñberganszone mit Welwitschia. Pp. 290–298. In: Spezielle Ökologie der tropischen und subtropischen Zonen Vol. 2. G. Fischer Verlag, Stuttgart.

    Google Scholar 

  • Waser, N. M. 1984. Sex ratio variation in populations of a dioecious desert perennial, Simmondsia chinensis. Oikos 42: 343–348.

    Google Scholar 

  • Zar, J. H. 1996. Biostatistical analysis. 3rd edition, Prentice-Hall, Upper Saddle River, New Jersey.

    Google Scholar 

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Henschel, J.R., Seely, M.K. Long-term growth patterns of Welwitschia mirabilis, a long-lived plant of the Namib Desert (including a bibliography). Plant Ecology 150, 7–26 (2000). https://doi.org/10.1023/A:1026512608982

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