Abstract
The grass flora of Namibia (374 species in 110 genera) shows surprisingly little variation in δ13C values along a rainfall gradient (50–600 mm) and in different habitat conditions. However, there are significant differences in the δ13C values between the metabolic types of the C4 photosynthetic pathway. NADP-ME-type C4 species exhibit the highest δ13C values (−11.7 ‰) and occur mainly in regions with high rainfall. NAD-ME-type C4 species have significantly lower δ13C values (−13.4 ‰) and dominate in the most arid part of the precipitation regime. PCK-type C4 species play an intermediate role (−12.5 ‰) and reach a maximum abundance in areas of intermediate precipitation. This pattern is also evident in genera containing species of different metabolic types. Within the same genus NAD species reach more negative δ13C values than PCK species and δ13C values decreased with rainfall. Also in Aristida, with NADP-ME-type photosynthesis, δ13C values decreased from −11 ‰ in the inland region (600 mm precipitation) to −15 ‰ near the coast (150 mm precipitation), which is a change in discrimination which is otherwise associated by a change in metabolism. The exceptional C3 species Eragrostis walteri and Panicum heterostachyum are coastal species experiencing 50 mm precipitation only. Many of the rare species and monotypic genera grow in moist habitats rather than in the desert, and they are not different in their carbon isotope ratios from the more common flora. The role of species diversity with respect to habitat occupation and carbon metabolism is discussed.
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Besler H (1972) Klimaverhältnisse und klimamorphologische Zonierung der zentralen Namib (Südwestafrika). Stuttg Geogr Stud 83: 1–209
Buchmann N, Brooks JR, Rapp KD, Ehleringer JR (1995) Carbon isotope ratios of C4 grasses is influenced by light and water supply. Plant Cell Environ (in press)
Clayton WD (1981) Evolution and distribution of grasses. Ann Miss Bot Gard 68: 5–14
Ehleringer JR, Monson RK (1993) Evolutionary and ecological aspects of photosynthetic pathway variation. Annu Rev Ecol Syst 24: 411–439
Ehleringer JR, Pearcy RW (1983) Variation in quantum yield for CO2 uptake among C3 and C4 plants. Plant Physiol 73: 555–559
Ehleringer JR, Hall AE, Farquhar GD (1993) Stable isotopes and plant carbon-water relations. Academic Press, San Diego
Ellis RP (1977a) Distribution of the Kranz syndrome in the southern African Eragrostoideae and Panicoideae according to bundle sheath anatomy and cytology. Agroplantae 9: 73–110
Ellis RP (1977b) Leaf anatomy of the South African Danthonieae (Poaceae) I. The genus Dregeochloa. Bothalia 12: 209–213
Ellis RP (1984a) Eragrostis walteri—a first record of non-Kranz leaf anatomy in the sub-family Chloridoideae (Poaceae). S Afr J Bot 3: 380–386
Ellis RP (1984b) Leaf anatomy of the South African Danthonieae (Poaceae). IX. Asthenatherum glaucum. Bothalia 15: 153–159
Ellis RP (1986) Leaf anatomy of the South African Danthonieae (Poaceae). XV. The genus Elytrophorus. Bothalia 16: 243–249
Ellis RP (1988) Leaf anatomy and systematics of Panicum (Poaceae: Panicoideae) in southern Africa. Monogr Syst Bot Miss Bot Gard 25: 129–156
Ellis RP (1990) Tannin-like substances in grass leaves. Mem Bot Surv S Afr 59: 59–77
Ellis RP, Vogel JC, Fuls A (1980) Photosynthetic pathways and the geographic distribution of grasses in South West Africa/Namibia. S Afr J Sci 76: 307–314
Evans JR, Sharkey TD, Berry JA, Farquhar GD (1986) Carbon isotope discrimination measured oncurrently with gas exchange to investigate CO2 diffusion in leaves of higher plants. Aust J Plant Physiol 13: 281–292
Farquhar GD (1983) On the nature of carbon isotope decrimination in C4 species. Aust J Plant Physiol 10: 205–226
Farquhar GD, Lloyd J (1993) Carbon and oxygen isotope effects in the exchange of carbon dioxide between terrestrial plants and the atmosphere. In: Ehleringer JR, Hall AE, Farquhar GD (eds) Stable isotopes and plant carbon-water relations. Academic Press, San Diego, pp 71–92
Gebauer G, Schulze E-D (1991) Carbon and nitrogen isotope ratios in different compartments of a healthy and a declining Picea abies forest in the Fichtelgebirge, NE Bavaria. Oecologia 87: 198–207
Gibbs Russell G, Watson GE, Koekemoer M, Smook L, Barker NP, Anderson HM, Dallwitz MJ (1990) Grasses of Southern Africa. Mem Bot Surv S Afr 58: 1–437
Giess W (1971) A preliminary vegetation map of South West Africa. Dinteria 4: 5–114
Hattersley PW (1982) δ13C values of C4 types in grasses. Aust J Plant Physiol 9: 139–154
Hattersley PW (1983) The distribution of C3 and C4 grasses in Australia in relation to climate. Oecologia 57: 113–128
Hattersley PW (1992) C4 photosynthetic pathways variation in grasses (Poaceae): its significance for arid and semi-arid lands. In: Chapman G (ed) Desertified grasslands: their biology and management. Academic Press, London, pp 181–212
Henderson S, Hattersley P, Caemmerer S von, Osmond CB (1994) Are C4 pathway plants threatened by global climatic change? In: Schulze E-D, Caldwell MM (eds) Ecophysiology of photosynthesis. (Ecological studies, vol 100) Springer, Berlin Heidelberg New York, pp 529–552
Merxmüller H (1970) Prodromus einer Flora von Südwestafrika. J. Cramer, Lehre
Mooney HA (1995) Global biodiversity assessment (GBA) Section 6: Biodiversity and ecosystem function: basic principles. UNEP, Nairobi
Müller MAN (1983) Grasses of South West Africa/Namibia. Department of Agriculture and Nature Conservation, Windhoek, Namibia
Müller MAN (1985) Gräser Südwestafrika/Namibias. J. Meinert, Windhoek
Osmond CB, Ziegler H, Stichler W, Trimborn P (1975) Carbon isotope discrimination in alpine succulent plants supposed to be capable of Crassulacean acid metabolism (CAM). Oecologia 28: 323–328
Pate JS, Hopper SD (1994) Rare and common plants in ecosystems, with special reference to the South-west Australian flora. Ecol Stud 99: 293–326
Penning de Vries FWT, Djitéye MA (1982) La productivité des paturages sahèliens. Pudoc, Wageningen
Prendergast HDV, Hattersley PW (1987) Australian C4 grasses (Poaceae): leaf blade anatomical features in relation to C4 acid decarboxylation types. Aust J Bot 35 355–382
Prendergast HDV, Hattersley PW, (1987) Australian C4 grasses (Poaceae): leaf blade anatomical features in relation to C4 acid decarboxylation types. Aust J Bot 35: 355–382
Prendergast HDV, Hattersley PW, Stone NE, Lazarides M (1986) C4 acid decarboxylation type in Eragrostis (Poaceae): patterns of variation in chloroplast position, ultrastructure and geographical distribution. Plant Cell Environ 9: 333–344
Prendergast HDV, Hattersley PW, Stone NE (1987) New structural/biochemical associations inleaf blades of C4 grasses (Poaceae). Aust J Plant Physiol 14: 403–420
Robicheaux RH, Pearcy RW (1984) Evolution of C3 and C4 plants along an environmental moisture gradient: patterns of photosynthetic differentiation in Hawaiian Scaevola and Euphorbia species. Am J Bot 71: 121–129
Schulze E-D, Mooney HA (1994) Biodiversity and ecosystem function (Ecological studies, vol 99) Springer, Berlin Heidelberg New York
Schulze E-D, Schulze I (1976) Distribution and control of photosynthetic pathways in plants growing in the Namib Desert, with special regard to Welwitschia mirabilis Hook. fil. Madoqua 9: 5–13
Schulze E-D, Gebauer G, Ziegler H, Lange OL (1991) Estimates of nitrogen fixation by trees on an aridity gradient in Namibia. Oecologia 88: 451–455
Teeri JA, Stowe LG (1976) Climatic patterns and the distribution of C4 grasses in North America. Oecologia 223: 1–12
Vogel JC, Fuls A, Ellis RP (1978) The geographical distribution of Kranz grasses in South Africa. S Afr J Sci 74: 209–215
Volk OH (1974) Gräser des Farmgebietes von Südwestafrika. Windhoek SAW Wiss. Gesellschaft
Walter H (1964) Die Vegetation der Erde in öko-physiologischer Betrachtung, vol I. Die tropischen und subtropischen Zonen. Fischer, Stuttgart
Walter H, Volk OH (1954) Grundlagen der Weidewirtschaft in Südwestafrika. Ulmer, Stuttgart
Watson L, Dallwitz MJ (1989) Grass genera of the world, 3rd edn, microfiche. Research School of Biological Sciences, Australian National University, Canberra
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Schulze, E.D., Ellis, R., Schulze, W. et al. Diversity, metabolic types and δ13C carbon isotope ratios in the grass flora of Namibia in relation to growth form, precipitation and habitat conditions. Oecologia 106, 352–369 (1996). https://doi.org/10.1007/BF00334563
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DOI: https://doi.org/10.1007/BF00334563