Monitoring and conserving mangrove forests under climate change
Photo by Megan L. Wood Mangroves are one of the most ecologically- and economically-important ecosystems in the world, providing habitat for high levels of both terrestrial and aquatic biodiversity, containing high diversity of fish, birds, fungi, bacteria, zooplankton, invertebrates, molluscs, reptiles and mammals, and many threatened and endemic species. As well as their high biodiversity value, mangroves also deliver many valuable ecosystem services such as providing breeding and nursery habitat for economically-important fish species, preventing coastal erosion, providing coastal protection from flooding and extreme weather events, and sequestering and storing enormous amounts of carbon in their vegetation and sediments. Mangroves have been estimated to provide at least US $1.6 billion each year in ecosystem services, while their economic value is thought to be US $200,000–900,000 per km2.
Matang Mangrove Forest, Malaysia 27 December 1999. Despite this, the relatively small area of global mangrove cover and their sensitivity to environmental changes means that they are now one of the world’s most threatened biomes. Mangroves and the services they provide are disappearing globally due to processes of land conversion and climate change. Global mangrove cover has decreased by 35% – and losses have been greatest in the Asian region. Mangrove loss is continuing at a rate of 2.1% per year, and it is predicted that 100% of mangrove forests could be lost over the next century if this rate of decline continues. As well as losses of biodiversity and global mangrove ecosystem services, many people live in mangrove forests around the world, and the loss of these systems also means destruction of natural resources that local communities rely upon for food and sustenance, fuel, and raw building materials.
Today Mangrove forests are an urgent global conservation priority, and this has now been heralded by the recent creation of the IUCN SSC Mangrove Specialist Group. In order to mitigate the loss of these highly unique, biodiverse systems and the services that they provide, conservation projects such as ZSL’s Community-based Mangrove Rehabilitation Project in The Philippines aim to restore and rehabilitate degraded mangrove forests around the world, in order to promote regeneration of these ecosystems. However, there is currently little known about the effectiveness of such programmes in restoring mangrove ecosystem health and function, particularly in the face of processes of global environmental change – land-use and climate change.
NDVI image of the Mangrove Forest near Douala, Cameroon In order to facilitate the implementation of successful management action for global mangrove systems, this project uses satellite- and ground-based monitoring to understand and predict the impacts of future climate change on intact and restored mangroves. This project uses freely-available satellite data and field-based monitoring to examine mangrove ecosystem health and ecosystem services provisioning under changing climates and management regimes, in order to determine the adaptation potential of natural, degraded and restored mangrove systems to future climatic changes. The project also aims to determine linkages and trade-offs between mangrove biodiversity and structure and ecosystem services provision, and to determine the potential future impacts of climate change on these relationships, in order to inform future mangrove management and conservation to protect these under future global environmental change.