Dispersal: Biogeography

Dispersal is one of the fundamental processes in biogeography, crucial to understanding the distribution of organisms. The most basic distinction between different types of dispersal is between organisms that disperse using their own energy and those that use energy from the environment. Dispersal can lead to two main patterns of range expansion. Either a population can slowly expand from the margins of its geographical range or a small number of individuals can disperse to a new location some distance from the current edge of the species range, or a combination of both of these processes can occur. Humans have assisted the dispersal of many organisms to new parts of the world – sometimes leading to problems when they become pests in their new range. Understanding dispersal is also important in attempting to predict how organisms will respond to climate change.

Key Concepts:

  • There are three fundamental processes in biogeography: evolution, extinction and dispersal.
  • The most basic distinction between types of dispersal is between organisms that disperse using their own energy (active dispersal) and those that use energy from the environment (passive dispersal).
  • Much of biodiversity is microscopic; organisms of this size can often be easily dispersed by air or water currents.
  • Many larger animals are capable of dispersal under their own power, especially ones that can fly such as birds and bats.
  • Individual organisms can sometimes appear at a location well outside their normal range, such individuals are referred to as vagrants.
  • There are two main patterns of range expansion ‘diffusion’ and ‘jump dispersal’.
  • Vicariance biogeography is an alternative to dispersal biogeography, which downplays the importance of dispersal, replacing it with the idea that a taxon's range can be divided by the formation of physical barriers.
  • A key applied question is whether organisms will be able to disperse at a speed that will allow them to track future climate change.
  • Human influence has had a big role in reducing the effects of dispersal barriers by moving organisms around the world.
  • When a species is dispersed to another part of the world by human actions, its main parasites and predators can be left behind; occasionally this can cause a dramatic increase in its population at the new site and the introduced organism can become a pest species.

Keywords: dispersal; biogeography; migration; climate change; jump dispersal; vicariance; vagrancy; nomadism

Figure 1. Role of the three fundamental processes in biogeography.
Figure 2. The Stinkhorn Phallus impudicus is a fungus found in both Europe and North America – although there are many closely related tropical forms. In these fungi the spores are dispersed mainly by flies, which are attracted to the strong smell of rotting flesh and then feed on the sticky spore mass – which can be seen in the photograph partly covering the top of the fruiting body. The flies then transport spores to new locations (Spooner and Roberts, 2005)
Figure 3. Types of range expansion. (a) Diffusion: range expansion as a steady expanding front. (b) Jump dispersal: founding a new population well outside the species current range. (c) Combination of diffusion and jump dispersal: over time the new population founded by a jump dispersal event may merge with the main population as both expand by diffusion.
Figure 4. Distribution of seed dispersal distances for many organisms has a very long tail with a few diaspores or individuals dispersing much further than the average distance. The shape of the curve illustrated is typical for plant species as different as the herb Asarum canadense and the tree Picea sp. Factors such as wind eddies (for wind dispersed trees) can make the tail surprisingly long (Horn, 2005). Active dispersal, for example by birds, is often assumed to be very important for the far right-hand side of the tail of this distribution – even for plant which have wind as there main dispersal mechanism (Wilkinson, 1997).
Figure 5. Canada goose, Branta canadensis in St James Park, London, England. This North American species was introduced into the Park by the mid-seventeenth Century and is now found over most of Britain. Indeed the specimen used by Linnaeus in his original description of this species came, not from North America, but from St James Park (Holloway, 1996).
close
 References
    book Baker RR (1982) Migration, Paths Through Time and Space. London: Hodder and Stoughton.
    book Bonner JT (2009) The Social Amoebae. Princeton: Princeton University Press.
    Brochet AL, Guillemain M, Fritz H, Gauthier-Clerc M and Green AJ (2010) Plant dispersal by teal (Anas crecca) in the Camargue: duck guts are more important than their feet. Freshwater Biology 55: 1262–1273.
    book Brown JH and Lomolino MV (1998) Biogeography. Sunderland, MA: Sinauer.
    Cain ML, Damman H and Muir A (1998) Seed dispersal and the Holocene migration of woodland herbs. Ecological Monographs 68: 325–347.
    Carlquist S (1981) Chance dispersal. American Scientist 69: 509–516.
    Clark JS (1998) Why trees migrate so fast: confronting theory with dispersal biology and the paleorecord. American Naturalist 152: 204–224.
    Clark JS, Fastie C, Hurtt G et al. (1998) Reid's paradox of rapid plant migration. Bioscience 48: 13–24.
    book Crawley MJ (1997) Plant Ecology, chap 19. Oxford: Blackwell.
    Dyer JM (1995) Assessment of climatic warming using a model of forest species migration. Ecological Modelling 79: 199–219.
    Finlay BJ (2002) Global dispersal of free-living microbial eukaryote species. Science 296: 1061–1063.
    Fischer SF, Poschlod P and Beinlich B (1996) Experimental studies on the dispersal of plants and animals on sheep in calcareous grassland. Journal of Applied Ecology 33: 1206–1222.
    book Gibbons DW, Reid JB and Chapman RA (1993) The New Atlas of Breeding Birds in Britain and Ireland: 1988–1991. London: T & AD Poyser.
    Hodkinson DJ and Thompson K (1997) Plant dispersal: the role of man. Journal of Applied Ecology 34: 1484–1496.
    book Holloway S (1996) The Historical Atlas of Breeding Birds in Britain and Ireland 1875–1900. London: T & AD Poyser.
    Horn HS (2005) Eddies at the gates. Nature 436: 179.
    book del Hoyo J, Elliott A and Christie DA (eds) (2010) Handbook of the Birds of the World, vol. 15. Barcelona: Lynx Edicions.
    Huntley B (1994) Plant species response to climate change: implications for the conservation of European birds. Ibis 137: s127–s138.
    Huntley B and Webb T (1989) Migration: species response to climatic variations caused by changes in the Earth's orbit. Journal of Biogeography 16: 5–19.
    Krause DW (2010) Washed up in Madagascar. Nature 463: 613–614.
    Litchman E (2010) Invisible invaders: non-pathergenic invasive microbes in aquatic and terrestrial ecosystems. Ecology Letters 13: 1560–1572.
    book Lovelock J (2009) The Vanishing Face of Gaia. London: Allen Lane.
    McLachlan JS, Clark JS and Manos PS (2005) Molecular indicators of tree migration capacity under rapid climate change. Ecology 86: 2008–2098.
    book Nee S (2007) "Metapopulations and their spatial dynamics". In: May RM and McLean AR (eds) Theoretical Ecology, 3rd edn. Oxford: Oxford University Press.
    book Nobel PS (1994) Remarkable Agaves and Cacti. Oxford: Oxford University Press.
    book Parenti LR and Ebach MC (2009) Comparative Biogeography. Berkeley: University of California Press.
    Preece RC (1998) Impact of early Polynesian occupation on the land snail fauna of Henderson Island, Pitcairn Group (South Pacific). Philosophical Transactions of the Royal Society of London B 353: 347–368.
    Sherratt TN, Lambin X, Petty SJ et al. (2000) Use of coupled oscillator models to understand synchrony and travelling waves in populations of the Field Vole Microtus agrestis in Northern England. Journal of Applied Ecology 37(suppl. 1): 148–158.
    Skellam JG (1951) Random dispersal in theoretical populations. Biometrika 38: 196–218.
    Smith HG and Wilkinson DM (2007) Not all free-living microorganisms have cosmopolitan distributions – the case of Nebela (Apodera) vas Certes (Protozoa:Amoebozoa:Arcellinida). Journal of Biogeography 34: 1822–1831.
    book Smith RIL (1993) "The role of bryophyte propagule banks in primary succession: case study of an Antarctic fellfeild soil". In: Miles J and Walton DWH (eds) Primary Succession on Land. Oxford: Blackwell.
    book Spooner B and Roberts P (2005) Fungi. London: Collins.
    book Van der Pijl L (1969) Principles of Dispersal in Higher Plants. Berlin: Springer-Verlag.
    Watts PC, Thorpe JP and Taylor PD (1998) Natural and anthropogenic dispersal mechanisms in the marine environment a study using cheilostome bryozoa. Philosophical Transactions of the Royal Society of London B 353: 453–464.
    Weimerskirch H and Wilson RP (2000) Oceanic respite for wandering albatrosses. Nature 406: 955–956.
    Wilkinson DM (1997) Plant colonization: are wind dispersed seeds really dispersed by birds at larger spatial and temporal scales? Journal of Biogeography 24: 61–65.
    Wilkinson DM (2010) Have we underestimated the importance of humans in the biogeography of free-living microorganisms? Journal of Biogeography 37: 393–397.
    Willis KJ, Rudner E and Sumegi P (2000) The full-Glacial forests of central and Southeastern Europe. Quaternary Research 53: 203–213.
    Wilson JB (1991) A comparison of biogeographic models: migration, vicariance and panbiogeography. Global Ecology and Biogeography Letters 1: 84–87.
 Further Reading
    book Baker RR (1978) The Evolutionary Ecology of Animal Migration. London: Hodder and Stoughton.
    book Cox CB and Moore PD (2010) Biogeography, 8th edn. Oxford: Blackwell.
    Green AJ, Figuerola J and Sánchez MI (2002) Implications of waterbird ecology for the dispersal of aquatic organisms. Acta Oecologica 12: 177–189.
    Moore PD (2001) The guts of seed dispersal. Nature 414: 406–407.
    Pitelka LF, Garden RH, Ash J et al. (1997) Plant migration and climate change. American Scientist 85: 464–473.
    book Silvertown J (2009) An Orchard Invisible, chap 10. Chicago: Chicago University Press.
    book Thornton I (1996) Krakatau. Cambridge, MA: Harvard University Press.
    book Thornton I (2007) Island Colonization; the Origin and Development of Island Communities. Cambridge: Cambridge University Press.
    book Whittaker RJ and Fernandez-Palacios JM (2006) Island Biogeography. Oxford: Oxford University Press.
Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Wilkinson, David M(May 2011) Dispersal: Biogeography. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0003237.pub2]