Greenhouse gas fluxes and flux changes from land-use dynamics in tropical wetlands

Tropical forested wetlands, especially peat
swamp forests and mangroves, provide numerous
environmental services and critical ecological
functions, affecting both upland and oceanic
ecosystems and the people who depend on them.
These forests offer protection from storms and
tsunamis, flood control, regulation of water quality,
breeding and rearing habitats for many species of
fish and shellfish, sources of wood and other forest
products, and great biodiversity as habitats for many
rare and endangered plant, animal and insect species.
They are also a source of nutrients and energy for
adjacent habitats including seagrass and coral reefs, and
are also valued for aesthetics and ecotourism. Tropical
wetlands have been used for centuries by indigenous
people for wood, thatch, medicines, dyes, and fish and
shellfish. Perhaps the least investigated, yet critically
important ecosystem service of tropical wetlands, is
providing a carbon sink. Because tropical wetlands
have high rates of primary productivity as well as
anaerobic soil conditions that limit decomposition,
carbon stocks are among the highest of any forest type.
Indonesia is a nation with remarkable wetlands and
associated resources. Approximately 47% of the
world’s tropical peatlands and 23% of its mangroves
occur throughout the archipelago. However,
Indonesia’s wetland forests are under considerable
pressure from land-use and land-cover change,
evidenced by high deforestation rates and fire
occurrence since 1980s. Deforestation of peat forests
is largely related to the establishment of unsustainable
oil palm and pulp wood plantations resulting in
the release of tremendous carbon emissions stored
in the peat. Losses of mangroves are largely due to
conversion to aquaculture, agriculture and coastal
development, and upstream disruptions to hydrology
and sediment delivery.
The extent of tropical wetlands, the magnitude of
loss, and the related socioeconomic ramifications of
the destruction of Indonesian wetlands are of global
significance. The carbon density and rates of land-cover
change in these ecosystems are amongst the highest
of any forest type on Earth. Therefore, addressing
interrelated issues of climate change and land use
could be valuable in generating new options on how
mangroves and peatlands should be best managed.
Preface
To help define the state of our knowledge on tropical
wetlands and the scientific information needed
to manage these ecosystems in a rapidly changing
world, a workshop was organised in Bali, Indonesia
in April 2011. This was part of the Tropical Wetlands
Initiative for Climate Adaptation and Mitigation
(TWINCAM), jointly implemented by the Center
for International Forestry Research (CIFOR) and the
United States Forest Service (USFS). The purpose of
the workshop was to bring together Indonesian and
international scientists from diverse backgrounds
and with diverse experiences in both freshwater and
coastal tropical wetlands to describe the state of the
science, significant research needs, and potential
transdisciplinary approaches necessary to implement
climate change adaptation and mitigation strategies.
Many of the world’s leading tropical wetlands
scientists attended the workshop, recognising the
need for research collaboration. We would like to
extend our thanks for their contributions in both
presentations and break-out group discussions. We
are also grateful to key speakers who set the scene,
including Jyrki Jauhiainen on greenhouse gas flux,
Boone Kauffman on carbon stock dynamics, Pep
Canadell on ecosystem modelling, Florian Siegert
on use of remote sensing, Louis Verchot on the
Intergovernmental Panel on Climate Change (IPCC)
processes, and Terry Hills on adaptation to climate
change. All presentations may be viewed at: http://
www.forestsclimatechange.org/events/ workshop-ontropical-
wetlandhtml.html.
We would also like to acknowledge the financial
support provided for this workshop by the United
States Department of State and the United States
Agency for International Development. Practical
assistance was provided by the Indonesian Forest
Research and Development Agency (FORDA) and
the Sekala Foundation, who we also thank.
Although the report’s focus is on tropical wetlands
of Indonesia, the results and recommendations
presented here are relevant and useful for those
interested in wetlands throughout the tropics.