Salt marsh canopy architecture differs with the number and composition of species

  • Published source details Keer G.H. & Zedler J.B. (2002) Salt marsh canopy architecture differs with the number and composition of species. Ecological Applications, 12, 456-473


This study is summarised as evidence for the following.

Action Category

Directly plant non-woody plants: brackish/saline wetlands

Action Link
Marsh and Swamp Conservation
  1. Directly plant non-woody plants: brackish/saline wetlands

    A replicated, randomized, paired, controlled study in 1997–2000 in an estuary in California, USA (Keer & Zedler 2002) found that plots planted with salt marsh vegetation typically contained more canopy layers and taller vegetation than unplanted plots, after four growing seasons. In three of three comparisons, planted plots had more canopy layers (2.1–2.8) than unplanted plots (1.7). Plots planted with three or six species had a greater maximum vegetation height (53–56 cm) than unplanted plots (41 cm). Plots planted with only one species had a similar vegetation height (46 cm) to the unplanted plots. The study also reported data from planted plots after two growing seasons. Plots planted with multiple species had greater overall vegetation cover, more canopy layers and a greater maximum vegetation height than plots planted with single species – but a similar average vegetation height (see original paper for data). Methods: In spring 1997, eight salt marsh herbs/succulents were planted into recently reprofiled intertidal sediment. In each of five areas, 14 random 4-m2 plots were planted with 90 greenhouse-reared seedlings (eight single-species plots, three three-species plots, three six-species plots) and three random plots were left unplanted. The planting areas had recently been excavated, amended with fine sediment, tilled and levelled. Non-planted vegetation was cleared from all plots during the first two growing seasons (1997–1998), but was left to grow from the third (1999–1998). Vegetation was surveyed using transects and point quadrats, in autumn 1997–2000. This study was based on the same experimental set-up as (13), (15) and (16).

    (Summarised by: Nigel Taylor)

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 18

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust