Study

A comparison of the vegetation and soils of natural, restored, and created coastal lowland wetlands in Hawai‘i

  • Published source details Bantilan-Smith M., Bruland G.L., MacKenzie R.A., Henry A.R. & Ryder C.R. (2009) A comparison of the vegetation and soils of natural, restored, and created coastal lowland wetlands in Hawai‘i. Wetlands, 29, 1023-1035.

Actions

This study is summarised as evidence for the following.

Action Category

Restore/create brackish/saline marshes or swamps (specific action unclear)

Action Link
Marsh and Swamp Conservation

Restore/create freshwater marshes or swamps (specific action unclear)

Action Link
Marsh and Swamp Conservation
  1. Restore/create brackish/saline marshes or swamps (specific action unclear)

    A replicated, site comparison study in 2007 in 35 freshwater, brackish and saline marshes in Hawaii, USA (Bantilan-Smith et al. 2009) found that restored/created marshes had statistically similar overall plant species richness, cover of wetland plant species and cover of exotic plant species to natural marshes, but that restored marshes had lower overall vegetation cover. Data were not reported for most outcomes. Overall vegetation cover was only 59% in restored marshes: significantly lower than the 74% cover in created wetlands and 76% cover in natural wetlands. The study suggests this may have been driven by management of restored wetlands for waterbirds, which require open water and mudflats. The study also reported differences in soil properties between restored/created and natural marshes. Methods: In March/April 2007, plant species and their cover were recorded in 35 coastal lowland marshes: 11 restored, 7 created and 17 natural. Six 1-m2 quadrats were surveyed in each marsh, across flooded, saturated and upland areas. Twenty-seven marshes brackish, saline or hypersaline. The other eight marshes were freshwater. The study does not report details of restoration/creation methods (including dates), or separate the effects of restoration/creation in marshes of different salinity.

    (Summarised by: Nigel Taylor)

  2. Restore/create freshwater marshes or swamps (specific action unclear)

    A replicated, site comparison study in 2007 of 35 freshwater, brackish and saline marshes in Hawaii, USA (Bantilan-Smith et al. 2009) found that restored/created marshes had statistically similar overall plant species richness, cover of wetland plant species and cover of exotic plant species to natural marshes, but that restored marshes had lower overall vegetation cover. Data were not reported for most outcomes. Overall vegetation cover was only 59% in restored marshes: significantly lower than the 74% cover in created wetlands and 76% cover in natural wetlands. The study suggests this may reflect management of restored wetlands for waterbirds, which require open water and mudflats. Methods: In March/April 2007, plant species and their cover were recorded in 35 coastal lowland marshes: 11 restored, 7 created and 17 natural. Six 1-m2 quadrats were surveyed in each marsh, across flooded, saturated and upland areas. Eight marshes were freshwater, whilst the other 27 were influenced by salt (brackish–hypersaline). The study does not report details of restoration/creation methods (including dates), or separate the effects of restoration/creation in marshes of different salinity.

    (Summarised by: Nigel Taylor)

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