within habitats in estuaries determined by environmental
gradients is shown in Figure 9 for mollusks.
Summary
Species zonation is a common feature within estuaries
where the combined and interactive effects of steep environmental gradients and food availability and to interspecies competition, herbivory, and predation result in
compositional changes in biotic assemblages across these
gradients. For vegetation and for rock-inhabiting biota, it
is often manifest as visually distinct communities occurring in bands. For infauna, it is expressed as compositional
and abundance changes in the communities across the
habitat. In areas of less steep environmental gradients,
species often occur in less differentiated formations, such
as mottled mosaics or with diffuse zonation.
Species zonation and changes in biotic assemblages can
be expressed across the whole of the estuary responding to
an along-estuarine environmental gradient of salinity,
from freshwater to marine, and a gradient in substrate
grain size. For zonation within a given habitat, while there
may be a range of factors that influence species zonation
that include wave energy, tidal currents, extent of water
turbidity, water depth, temperature, degree of light penetration, pH, and nutrients, some of the main environmental
determinants for forcing species zonation are pore-water
salinity, open-water salinity, substrate type, and inundation. These affect the survivorship of a given species,
determine the suitability of a habitat for an organism,
and also affect the microbiota in the environment that
influence the occurrence of macrofauna and macroflora.
One of the best examples of species zonation in estuaries
is afforded by mangroves in tropical regions and saltmarsh
on tidal flats in temperate regions in response to tidal flat
environmental gradients. For example, in mangroves with
strong environmental gradients of salinity and inundation,
there is zonation of the species in terms of composition,
vegetation structure, and plant physiognomy.
Bibliography
Bezerra, L. E. A., Dias, C. B., Santana, G. X., and MatthewsCascon, H., 2006. Spatial distribution of fiddler crabs (genus
Uca) in a tropical mangrove of northeast Brazil. Scientia
Marina, 70, 759–766.
Bridgewater, P. B., 1975. Peripheral vegetation of Westernport Bay.
Proceedings of the Royal Society of Victoria, 87, 69–78.
Bridgewater, P. B., and Cresswell, I. D., 1993. Phytosociology, and
phytogeography of Western Australian salt marshes. Fragmenta
Flora Geobotanica Supplementum, 2, 609–629.
Chakraborty, S. K., and Choudhury, A., 1985. Distribution of fiddler crabs in Sundarbans mangrove estuarine complex, India.
In Bhosale, L. J. (ed.), Proceedings of National Symposium on
Biology, Utilization and Conservation of Mangroves. Kolhapur:
Shivaji University Press, pp. 467–472.
Chapman, V. J., 1938. Studies in salt-marsh ecology: sections I to
III. Journal of Ecology, 26, 144–179.
Crane, J., 1975. Fiddler Crabs of the World (Ocypodidae: Genus
Uca). Princeton: Princeton University Press.
Cresswell, I. D., 2000. Ecological significance of freshwater seeps
along the western shore of the Leschenault Inlet estuary. Journal
of the Royal Society of Western Australia, 83, 285–292.
Cresswell, I. D., and Bridgewater, P. B., 1998. Major plant communities of coastal saltmarsh vegetation in Western Australia. In
McComb, A. J., and Davis, J. A. (eds.), Wetlands for the Future.
South Australia: Gleneagles Publishing, pp. 297–326.
Dittmann, S., 2000. Zonation of benthic communities in a tropical
tidal flat of north-east Australia. Journal of Sea Research, 43,
33–51.
Dürr, V., and Semeniuk, T. A., 2000. Long-term spatial dynamics of
polychaetes in Leschenault Inlet estuary. Journal of the Royal
Society of Western Australia, 83, 463–474.
Emery, N. C., Ewanchuk, P. J., and Bertness, M. D., 2001. Competition and salt-marsh plant zonation: stress tolerators may be
dominant competitors. Ecology, 82, 2471–2485.
Levinton, J. S., 1995. Marine Biology: Function, Biodiversity, Ecology. Oxford: Oxford University Press.
McLachlan, A., 1996. Physical factors in benthic ecology: effects of
changing sand particle size on beach fauna. Marine Ecology
Progress Series, 131, 205–211.
Mitsch, W. J., and Gosselink, J. G., 1993. Wetlands, 2nd edn.
New York: Van Nostrand Reinhold, pp. 189–265.
Paine, R. T., 1974. Intertidal community structure: experimental
studies on the relationship between a dominant competitor and
its principal predator. Oecologia, 15, 93–120.
Pen, L., Semeniuk, V., and Semeniuk, C. A., 2000. Peripheral wetland habitats and vegetation of Leschenault Inlet estuary. Journal of the Royal Society of Western Australia Special Issue on
the Leschenault Inlet Estuary, 83, 293–316.
Pennings, S. C., and Callaway, R. M., 1992. Salt marsh plant zonation: the relative importance of competition and physical factors.
Ecology, 73, 681–690.
Pennings, S. C., Grant, M.-B., and Bertness, M. D., 2005. Plant
zonation in low-latitude salt marshes: disentangling the roles of
flooding, salinity and competition. Journal of Ecology, 93,
159–167.
Semeniuk, V., 1983. Mangrove distribution in Northwestern Australia in relationship to freshwater seepage. Vegetatio, 53, 11–31.
Semeniuk, T. A., 2000. Small benthic Crustacea of the Leschenault
Inlet estuary. Journal of the Royal Society of Western Australia,
83, 429–441.
Semeniuk, V., and McNamara, K. J., 2009. The power of stratigraphy in determining biological evolutionary patterns. Journal of
the Royal Society of Western Australia, 92: 407–430.
Semeniuk, V., and Wurm, P. A. S., 2000. Molluscs of the Leschenault
Inlet estuary – their diversity, distribution, and population dynamics. Journal of the Royal Society of Western Australia Special Issue
on the Leschenault Inlet Estuary, 83, 377–418.
Silvestri, S., Defina, A., and Marani, M., 2005. Tidal regime, salinity and salt marsh plant zonation. Estuarine Coastal Shelf Science, 62, 119–130, doi:10.1016/j.ecss.2004.08.010.
Tomlinson, P. B., 1986. The Botany of Mangroves. Cambridge:
Cambridge University Press. Cambridge Tropical Biology
Series.
Unno, J., and Semeniuk, V., 2009. The habitats of the Western Australian soldier crab Mictyris occidentalis Unno 2008 (Brachyura:
Mictyridae) across its biogeographical range. Journal of the
Royal Society of Western Australia, 92, 289–363.
Cross-references
Mangroves
Saltmarshes
Tidal Flat Salinity Gradient
SPECIES ZONATION
621
gradients is shown in Figure 9 for mollusks.
Summary
Species zonation is a common feature within estuaries
where the combined and interactive effects of steep environmental gradients and food availability and to interspecies competition, herbivory, and predation result in
compositional changes in biotic assemblages across these
gradients. For vegetation and for rock-inhabiting biota, it
is often manifest as visually distinct communities occurring in bands. For infauna, it is expressed as compositional
and abundance changes in the communities across the
habitat. In areas of less steep environmental gradients,
species often occur in less differentiated formations, such
as mottled mosaics or with diffuse zonation.
Species zonation and changes in biotic assemblages can
be expressed across the whole of the estuary responding to
an along-estuarine environmental gradient of salinity,
from freshwater to marine, and a gradient in substrate
grain size. For zonation within a given habitat, while there
may be a range of factors that influence species zonation
that include wave energy, tidal currents, extent of water
turbidity, water depth, temperature, degree of light penetration, pH, and nutrients, some of the main environmental
determinants for forcing species zonation are pore-water
salinity, open-water salinity, substrate type, and inundation. These affect the survivorship of a given species,
determine the suitability of a habitat for an organism,
and also affect the microbiota in the environment that
influence the occurrence of macrofauna and macroflora.
One of the best examples of species zonation in estuaries
is afforded by mangroves in tropical regions and saltmarsh
on tidal flats in temperate regions in response to tidal flat
environmental gradients. For example, in mangroves with
strong environmental gradients of salinity and inundation,
there is zonation of the species in terms of composition,
vegetation structure, and plant physiognomy.
Bibliography
Bezerra, L. E. A., Dias, C. B., Santana, G. X., and MatthewsCascon, H., 2006. Spatial distribution of fiddler crabs (genus
Uca) in a tropical mangrove of northeast Brazil. Scientia
Marina, 70, 759–766.
Bridgewater, P. B., 1975. Peripheral vegetation of Westernport Bay.
Proceedings of the Royal Society of Victoria, 87, 69–78.
Bridgewater, P. B., and Cresswell, I. D., 1993. Phytosociology, and
phytogeography of Western Australian salt marshes. Fragmenta
Flora Geobotanica Supplementum, 2, 609–629.
Chakraborty, S. K., and Choudhury, A., 1985. Distribution of fiddler crabs in Sundarbans mangrove estuarine complex, India.
In Bhosale, L. J. (ed.), Proceedings of National Symposium on
Biology, Utilization and Conservation of Mangroves. Kolhapur:
Shivaji University Press, pp. 467–472.
Chapman, V. J., 1938. Studies in salt-marsh ecology: sections I to
III. Journal of Ecology, 26, 144–179.
Crane, J., 1975. Fiddler Crabs of the World (Ocypodidae: Genus
Uca). Princeton: Princeton University Press.
Cresswell, I. D., 2000. Ecological significance of freshwater seeps
along the western shore of the Leschenault Inlet estuary. Journal
of the Royal Society of Western Australia, 83, 285–292.
Cresswell, I. D., and Bridgewater, P. B., 1998. Major plant communities of coastal saltmarsh vegetation in Western Australia. In
McComb, A. J., and Davis, J. A. (eds.), Wetlands for the Future.
South Australia: Gleneagles Publishing, pp. 297–326.
Dittmann, S., 2000. Zonation of benthic communities in a tropical
tidal flat of north-east Australia. Journal of Sea Research, 43,
33–51.
Dürr, V., and Semeniuk, T. A., 2000. Long-term spatial dynamics of
polychaetes in Leschenault Inlet estuary. Journal of the Royal
Society of Western Australia, 83, 463–474.
Emery, N. C., Ewanchuk, P. J., and Bertness, M. D., 2001. Competition and salt-marsh plant zonation: stress tolerators may be
dominant competitors. Ecology, 82, 2471–2485.
Levinton, J. S., 1995. Marine Biology: Function, Biodiversity, Ecology. Oxford: Oxford University Press.
McLachlan, A., 1996. Physical factors in benthic ecology: effects of
changing sand particle size on beach fauna. Marine Ecology
Progress Series, 131, 205–211.
Mitsch, W. J., and Gosselink, J. G., 1993. Wetlands, 2nd edn.
New York: Van Nostrand Reinhold, pp. 189–265.
Paine, R. T., 1974. Intertidal community structure: experimental
studies on the relationship between a dominant competitor and
its principal predator. Oecologia, 15, 93–120.
Pen, L., Semeniuk, V., and Semeniuk, C. A., 2000. Peripheral wetland habitats and vegetation of Leschenault Inlet estuary. Journal of the Royal Society of Western Australia Special Issue on
the Leschenault Inlet Estuary, 83, 293–316.
Pennings, S. C., and Callaway, R. M., 1992. Salt marsh plant zonation: the relative importance of competition and physical factors.
Ecology, 73, 681–690.
Pennings, S. C., Grant, M.-B., and Bertness, M. D., 2005. Plant
zonation in low-latitude salt marshes: disentangling the roles of
flooding, salinity and competition. Journal of Ecology, 93,
159–167.
Semeniuk, V., 1983. Mangrove distribution in Northwestern Australia in relationship to freshwater seepage. Vegetatio, 53, 11–31.
Semeniuk, T. A., 2000. Small benthic Crustacea of the Leschenault
Inlet estuary. Journal of the Royal Society of Western Australia,
83, 429–441.
Semeniuk, V., and McNamara, K. J., 2009. The power of stratigraphy in determining biological evolutionary patterns. Journal of
the Royal Society of Western Australia, 92: 407–430.
Semeniuk, V., and Wurm, P. A. S., 2000. Molluscs of the Leschenault
Inlet estuary – their diversity, distribution, and population dynamics. Journal of the Royal Society of Western Australia Special Issue
on the Leschenault Inlet Estuary, 83, 377–418.
Silvestri, S., Defina, A., and Marani, M., 2005. Tidal regime, salinity and salt marsh plant zonation. Estuarine Coastal Shelf Science, 62, 119–130, doi:10.1016/j.ecss.2004.08.010.
Tomlinson, P. B., 1986. The Botany of Mangroves. Cambridge:
Cambridge University Press. Cambridge Tropical Biology
Series.
Unno, J., and Semeniuk, V., 2009. The habitats of the Western Australian soldier crab Mictyris occidentalis Unno 2008 (Brachyura:
Mictyridae) across its biogeographical range. Journal of the
Royal Society of Western Australia, 92, 289–363.
Cross-references
Mangroves
Saltmarshes
Tidal Flat Salinity Gradient
SPECIES ZONATION
621