157
© Springer Nature Switzerland AG 2020
A. Mitra, Mangrove Forests in India,
https://doi.org/10.1007/978-3-030-20595-9_6
Chapter 6
Mangroves: A Potential Vegetation Against
Sea Level Rise
Abstract Mangroves possess the ability to adapt to changes in sea level by growing
upward in place, or by expanding landward or seaward. Mangroves produce peat
from decaying litter fall and root growth and by trapping sediment from the ambient
water. The process of building peat helps mangroves keep up with sea level rise.
Mangroves can also expand their range despite sea level rise if the rate of sediment
accretion is sufficient to keep up with sea level rise and if migration is not blocked
by local conditions, such as infrastructure (e.g., roads, agricultural fields, dikes,
urbanization, seawalls, and shipping channels) and topography (e.g., steep slopes).
The potential of mangroves to combat sea level rise has been explained in this chapter with several regional case studies.
Keywords Sea level · Peat · Sediment accretion · Mangrove migration
Absolute sea-level rise is the increase in the average sea level across the globe. It’s
no exaggeration to say that all throughout the earth the sea level is jumping higher
and higher above the standard mean sea level (local-specific) with the passage of
time. However, this jumping rate is not uniform in every coasts and is regulated by
local factors like land subsidence (or sinking) and wind and ocean circulations.
The increase in global temperature triggers the process of expansion of ocean
water volume and additional input of waters from sources like glaciers, which
were locked on the land. This causes the level of seawater to rise from its normal
position. The sea level has elevated more than 120 metres since the peak of the last
ice age about 18,000 years ago. The bulk of that occurred before 6000 years ago.
From 3000 years ago to the start of the nineteenth century, sea level was almost
constant, rising at 0.10–0.20 mm/year. Since 1900, the level has risen at 1.00–
2.00 mm/year (http://www.grida.no/climate/ipcc_tar/wg1/295.htm), and since
1992, satellite altimetry from TOPEX/Poseidon indicates a rate of approximately
3.00 mm/year (http://www.grida.no/climate/ipcc_tar/wg1/295.htm). An increase
of 1.5–4.5 °C temperature is estimated to lead to an increase of 15–95 cm of the
sea level (IPCC 2001).
© Springer Nature Switzerland AG 2020
A. Mitra, Mangrove Forests in India,
https://doi.org/10.1007/978-3-030-20595-9_6
Chapter 6
Mangroves: A Potential Vegetation Against
Sea Level Rise
Abstract Mangroves possess the ability to adapt to changes in sea level by growing
upward in place, or by expanding landward or seaward. Mangroves produce peat
from decaying litter fall and root growth and by trapping sediment from the ambient
water. The process of building peat helps mangroves keep up with sea level rise.
Mangroves can also expand their range despite sea level rise if the rate of sediment
accretion is sufficient to keep up with sea level rise and if migration is not blocked
by local conditions, such as infrastructure (e.g., roads, agricultural fields, dikes,
urbanization, seawalls, and shipping channels) and topography (e.g., steep slopes).
The potential of mangroves to combat sea level rise has been explained in this chapter with several regional case studies.
Keywords Sea level · Peat · Sediment accretion · Mangrove migration
Absolute sea-level rise is the increase in the average sea level across the globe. It’s
no exaggeration to say that all throughout the earth the sea level is jumping higher
and higher above the standard mean sea level (local-specific) with the passage of
time. However, this jumping rate is not uniform in every coasts and is regulated by
local factors like land subsidence (or sinking) and wind and ocean circulations.
The increase in global temperature triggers the process of expansion of ocean
water volume and additional input of waters from sources like glaciers, which
were locked on the land. This causes the level of seawater to rise from its normal
position. The sea level has elevated more than 120 metres since the peak of the last
ice age about 18,000 years ago. The bulk of that occurred before 6000 years ago.
From 3000 years ago to the start of the nineteenth century, sea level was almost
constant, rising at 0.10–0.20 mm/year. Since 1900, the level has risen at 1.00–
2.00 mm/year (http://www.grida.no/climate/ipcc_tar/wg1/295.htm), and since
1992, satellite altimetry from TOPEX/Poseidon indicates a rate of approximately
3.00 mm/year (http://www.grida.no/climate/ipcc_tar/wg1/295.htm). An increase
of 1.5–4.5 °C temperature is estimated to lead to an increase of 15–95 cm of the
sea level (IPCC 2001).