Study

Mangrove expansion and population structure at a planted site, East London, South Africa

  • Published source details Hoppe-Speer S.C., Adams J.B. & Rajkaran A. (2015) Mangrove expansion and population structure at a planted site, East London, South Africa. Southern Forests, 77, 131-139.

Actions

This study is summarised as evidence for the following.

Action Category

Restore/create brackish/saline swamps in areas that will be climatically suitable in the future

Action Link
Marsh and Swamp Conservation

Directly plant trees/shrubs: brackish/saline wetlands

Action Link
Marsh and Swamp Conservation
  1. Restore/create brackish/saline swamps in areas that will be climatically suitable in the future

    A before-and-after study in 1969–2011 in an estuary in South Africa (Hoppe-Speer et al. 2015) reported that over 42 years after planting mangrove trees just outside their current range, the area of mangrove vegetation increased. Before planting, there were no mangroves present in the estuary. In the year after planting (1970), mangrove forests could not be identified on aerial photographs. Forty-two years after planting (2011), mangrove forests had established and covered 1.6 ha. Although mangroves encroached into and replaced existing salt marshes, the area of salt marsh in the estuary actually increased slightly over time (1970: 2.9 ha; 2011: 3.1 ha). Salt marshes developed on newly deposited sediment. Methods: In 1969, twenty-five grey mangrove Avicennia marina trees (age unclear) were planted into salt marsh in the Nahoon Estuary. This site is 60 km south of naturally occurring mangrove forests in South Africa. “A few” mangrove trees of other species were planted “a few” years later. The area of mangrove forest and salt marsh in the estuary was determined from aerial photographs (taken 1970–2004), satellite images (taken 2004–2010) and field surveys (2011).

    (Summarised by: Nigel Taylor)

  2. Directly plant trees/shrubs: brackish/saline wetlands

    A before-and-after study in 1969–2011 in an estuary in South Africa (Hoppe-Speer et al. 2015) reported that over 42 years after planting mangrove trees, the area of mangrove vegetation increased. Before planting, there were no mangroves present in the estuary. In the year after planting (1970), mangrove forests could not be identified on aerial photographs. Forty-two years after planting (2011), mangrove forests had established and covered 1.6 ha. Although mangroves encroached into and replaced existing salt marshes, the area of salt marsh in the estuary actually increased slightly over time (1970: 2.9 ha; 2011: 3.1 ha). Salt marshes developed on newly deposited sediment. Methods: In 1969, twenty-five grey mangrove Avicennia marina trees (age unclear) were planted into salt marsh in the Nahoon Estuary. This site is 60 km south of naturally occurring mangrove forests in South Africa. “A few” mangrove trees of other species were planted “a few” years later. The area of mangrove forest and salt marsh in the estuary was determined from aerial photographs (taken 1970–2004), satellite images (taken 2004–2010) and field surveys (2011).

    (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