Tropical peat debris storage in the tidal flat in northern part of the Bengkalis island, Indonesia

Abstract

Currently, CO2 emissions from the peat is a global problem. Particularly, it is caused by biodegradation of dry peat or peat fire. In the northern coast of Bengkalis island, peat is flowing out due to coastal erosion, and mangrove tidal flat is formed the west coast by peat. The core samples of the mangrove have been confirmed that the clay layer and the peat layer are in mutual layers, and decomposition was inhabited because these sandwiched peat soils was an anoxic state. In the northern part of the Bengkalis island, peat is sandwiched in the clay layer. Biodegradation can be suppressed by being sandwiched, there is a possibility of suppressing the amount of peat decomposed by providing a place to store peat in tidal flats. In this research, we examined the degree of decomposition of peat accumulated in the mangrove tidal flats and confirmed that decomposition was suppressed for the peat soils in the tidal flat under mangrove trees, we call it “sandwich effect”. The peat materials in deeper layer came from originally peat swamp forest, however, the surface organic materials were thought to be come from mangrove materials. Considering the change from 1988 to 2015, the carbon fixation rate by mangrove is 1.7 × 103 tC km-2 yr-1, the carbon accumulation rate by accumulation of secondary deposition of peat was 7.4×103 tC km-2 yr-1.

Sea level rise and climate change acting as interactive stressors on development and dynamics of tropical peatlands in coastal Sumatra and South Borneo since the Last Glacial Maximum

“…It can be inferred that the future SLR, when interacting with continuing severe anthropogenic impact, for example, extensive PSF degradation, peatland drainage and intentional burning (Puspitaloka et al, 2021), will also possibly create synergistic negative impacts. Although SLR is predicted to increase peatland water tables and potentially leads to increased peat accumulation in healthy/intact ecosystems (Cobb et al, 2017), it will enable high‐energy waves to reach farther up or inland thus exacerbating the already severe and/or initiate peat abrasion on coastal areas with severe mangrove degradation and subsequent peat failure/landslide such as in Bengkalis Island, Indonesia (Sutikno et al, 2017; Yamamoto et al, 2019). SLR is also predicted to result in widespread seawater inundation following subsidence in degraded and drained peatlands (Hoyt et al, 2020; Whittle & Gallego‐Sala, 2016) and will foreseeably rapidly kill the freshwater PSF vegetation.…”

Detection Of Peatland Coastline Changes Due To Land Use Change On Bengkalis Island, Riau, Indonesia

“…Bengkalis Island consists of almost all parts of the garden which is managed as one of the main livelihoods of the surrounding community. Most of the land on Bengkalis Island is a peat area with a depth of approximately 1 meter so Bengkalis Island is included in one of the Indonesian Peat Hydrological Areas (KHGI) [10]. On Bengkalis Island there are domed peat deposits marked by radial drainage patterns, each peat dome deposit is characteristic of morphology for peat in the tropics.…”

Tropical peat subsidence rates are related to decadal LULC changes: Insights from InSAR analysis

“…Significant subsidence areas are recorded in the north-western tip (Area 1), with the highest rate of -17.416 cm/year, due to the bog bursts. This phenomenon is induced by coastal erosion and peat landslide that causes the peat flowing out to the sea at a rapid rate (Yamamoto et al, 2019).…”

“…The subsidence in about half of Area 1 is mostly affected by the peat burst driven by coastal erosion. The eroded peatlands then formed a secondary decomposition sandwiched with clay layers in an anaerobic condition (Yamamoto et al, 2019).…”

“…Nonetheless, this phenomenon has the potential of carbon accumulation, annually accounting for 7.4x10 3 tC/km 2 (Yamamoto et al, 2019), becoming worth exploring for future studies.…”