73
© Springer Nature Singapore Pte Ltd. 2019
T. Kuwae, M. Hori (eds.), Blue Carbon in Shallow Coastal Ecosystems,
https://doi.org/10.1007/978-981-13-1295-3_3
Chapter 3
Carbon Sequestration in Mangroves
Tomomi Inoue
Abstract Mangrove ecosystems are widely regarded as highly productive, and the
high ability of mangroves to store carbon is currently receiving much attention in
the context of climate change. Globally, mangroves are estimated to occupy an area
of 152,361 km
2
. A model relating mangrove biomass to temperature and precipitation has been used, together with global mangrove distribution maps, to estimate the
total aboveground biomass worldwide as 2.83 Pg dry weight (95% confidence interval 2.18–3.40 Pg), and the base area average as 184.8 t dry weight ha
−1
(95% CI
142.1–222.0 t ha
−1
). Almost half of the total global mangrove biomass is in Southeast
Asia. The global mangrove belowground biomass has been estimated to be 1.11 Pg
dry weight (95% CI 0.74–1.64 Pg). Thus, the total estimated biomass (aboveground
+ belowground) is 3.94 Pg dry weight. Estimates of carbon storage as necromass
(dead organic matter) in mangrove soils differ. By one estimate, 5.00 Pg C is stored
globally as necromass. By another estimate, ~2.6 Pg C is stored globally, and the
whole mangrove ecosystem stores ~4.4 Pg C.
3.1 Introduction
Although mangrove ecosystems are confined to coastal areas of the tropics and subtropics, they are now being widely and frequently discussed, especially in an environmental context, in part because they are being seriously threatened around the
world by loss of area and degradation. In the Indo-West Pacific region, where the
species diversity of mangroves is highest, the area occupied by mangrove ecosystems has decreased by approximately 1% a year during the past 30 years (FAO 2007).
At this rate, mangrove ecosystems in this region are likely to disappear within a
hundred years. This possibility highlights how precious mangroves are to us.
The astonishing mangrove trees have intrigued mangrove researchers for many
years. Mangrove plants grow in the intertidal environment. To survive and flourish
T. Inoue (*)
National Institute for Environmental Studies, Japan, Onogawa, Tsukuba, Ibaraki, Japan
e-mail: tomomi.inoue@nies.go.jp
© Springer Nature Singapore Pte Ltd. 2019
T. Kuwae, M. Hori (eds.), Blue Carbon in Shallow Coastal Ecosystems,
https://doi.org/10.1007/978-981-13-1295-3_3
Chapter 3
Carbon Sequestration in Mangroves
Tomomi Inoue
Abstract Mangrove ecosystems are widely regarded as highly productive, and the
high ability of mangroves to store carbon is currently receiving much attention in
the context of climate change. Globally, mangroves are estimated to occupy an area
of 152,361 km
2
. A model relating mangrove biomass to temperature and precipitation has been used, together with global mangrove distribution maps, to estimate the
total aboveground biomass worldwide as 2.83 Pg dry weight (95% confidence interval 2.18–3.40 Pg), and the base area average as 184.8 t dry weight ha
−1
(95% CI
142.1–222.0 t ha
−1
). Almost half of the total global mangrove biomass is in Southeast
Asia. The global mangrove belowground biomass has been estimated to be 1.11 Pg
dry weight (95% CI 0.74–1.64 Pg). Thus, the total estimated biomass (aboveground
+ belowground) is 3.94 Pg dry weight. Estimates of carbon storage as necromass
(dead organic matter) in mangrove soils differ. By one estimate, 5.00 Pg C is stored
globally as necromass. By another estimate, ~2.6 Pg C is stored globally, and the
whole mangrove ecosystem stores ~4.4 Pg C.
3.1 Introduction
Although mangrove ecosystems are confined to coastal areas of the tropics and subtropics, they are now being widely and frequently discussed, especially in an environmental context, in part because they are being seriously threatened around the
world by loss of area and degradation. In the Indo-West Pacific region, where the
species diversity of mangroves is highest, the area occupied by mangrove ecosystems has decreased by approximately 1% a year during the past 30 years (FAO 2007).
At this rate, mangrove ecosystems in this region are likely to disappear within a
hundred years. This possibility highlights how precious mangroves are to us.
The astonishing mangrove trees have intrigued mangrove researchers for many
years. Mangrove plants grow in the intertidal environment. To survive and flourish
T. Inoue (*)
National Institute for Environmental Studies, Japan, Onogawa, Tsukuba, Ibaraki, Japan
e-mail: tomomi.inoue@nies.go.jp