Do all the seedlings survive?
Coastal wetlands — such as mangrove forests — are more dynamic than land-based habitats: they are submerged in water for part of each day, depending on when the tides come in and roll out. If the water level is wrong, seedlings from restoration projects do not survive. Planting mangroves at the incorrect topography often results in inappropriate soil conditions for seedlings. Disturbances and stresses caused by cattle trampling, browsing (animals feeding on leaves, twigs, or other high-growing vegetation), algae growth, and insect attacks also lead to low survival rates [1].
Moreover, mangrove forests are complex ecosystems, formed from many tree, shrub, and fern species. Typically, mangrove planting efforts focus on a single species, making it more difficult for seedlings to survive. A mismatch of this kind between the aim of such restoration projects and the realities on the ground has severe economic consequences and shows that planting is not always the best option.
However, with the right checks and balances, planting mangroves can make a big impact for the planet. You can learn how Only One approaches their projects to protect and revitalize mangroves on their Projects page.
- Kodikara, K. A. S., Mukherjee, N., & Jayatissa, L. P., Dahdouh-Guebas, F., & Koedam, N. (2017), Have mangrove restoration projects worked? An in-depth study in Sri Lanka. Restor Ecol, 25: 705-716. doi: 10.1111/rec.12492.
About the author
Vasiliki I. Chalastani is a PhD candidate at the Laboratory of Harbour Works, National Technical University of Athens (NTUA), Greece. Her thesis, “Optimization Approaches for Marine Spatial Planning,” aims to develop tools for optimal use of the marine environment through reconciliation of human activities and conservation features. Previously, following her undergraduate studies as a civil engineer at NTUA, Chalastani pursued her MSc, “Water Air Pollution and Energy at Global and Regional Scales,” at École Polytechnique, Paris, France. While in France, she has completed an internship at the Laboratoire Océanographique de Villefranche and at École Normale Supérieure on ocean-based solutions. From 2018 to 2019, Chalastani acted as a consultant for the Alternate Minister of Maritime Affairs and Insular Policy of Greece, Nektarios Santorinios. In 2018, she worked for the Institute for Sustainable Development and International Relations (IDDRI), Paris, with Alexandre K. Magnan, on the issue of climate change adaptation. In 2019, Chalastani worked for the Saudi Red Sea Project, developing a preliminary marine spatial planning initiative, under the supervision of Carlos M. Duarte. She is a member of the National Chamber of Engineers and the United Nations Sustainable Development Solutions Network (UN SDSN), Greece.