A comparison of natural and created depressional wetlands in central Oklahoma using metrics from indices of biological integrity

  • Published source details Hartzell D., Bidwell J.R. & Davis C.A. (2007) A comparison of natural and created depressional wetlands in central Oklahoma using metrics from indices of biological integrity. Wetlands, 27, 794-805.


This study is summarised as evidence for the following.

Action Category

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

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

    A replicated, site comparison study in 2004–2005 of 18 freshwater marshes in Oklahoma, USA (Hartzell et al. 2007) found that created marshes contained a greater proportion of perennial plant species than natural marshes, but that other vegetation metrics were similar in created and natural marshes. After >20 years, 94% of the plant species in created marshes were perennial – significantly greater than the 78% of perennial species in natural marshes. All other vegetation metrics were statistically similar in each type of marsh. These included taxonomic richness (created: 6.9; natural: 6.9 taxa/marsh), taxonomic diversity (data reported as a diversity index), proportion of wetland-characteristic species (created: 77%; natural: 67%), vegetation quality (data reported as an index based on how characteristic each plant species is of undisturbed local habitats) and percent cover of the dominant species (created: 55%; natural: 49%). Methods: In summer 2004 and 2005, herbaceous plant species and their cover were recorded in six created wetlands (>20 years old; identified based on the presence of a dam or levee, and soil characteristics) and 12 natural wetlands. All wetlands were <1.1 ha. The study does not report further details of wetland creation methods. The created wetlands had deeper, less turbid water than the natural wetlands and were typically flooded for longer. Vegetation was surveyed in four 0.5-m2 quadrats/broad vegetation type/wetland/year.

    (Summarised by: Nigel Taylor)

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