Metagenomic Identification and Classification of the Mercury-Methylating Gene hgcA in Response to Water Table and Plant Functional Group Manipulations in Peat Soil

Abstract. A limited number of publications in the literature deal with the measurement of actual evapotranspiration (AET) from a peat soil. AET is an important parameter in the description of water pathways of an ecosystem. In peatlands, where the water table is near the surface and the vegetation is composed of nonvascular plants without stomatal resistance, the AET measurement represents a challenge. This paper discusses the development of an automated lysimeter installed between 12 and 27 July 2010, at a 11-ha bog site, Pont-Rouge (42 km west of Quebec City, Canada). This system was made of an isolated block of peat, maintained at the same water level as the surrounding water table by a system of submersible pressure transmitters and pumps. The change in water level in millimetres in the isolated block of peat was used to calculate the water lost through evapotranspiration (ET) while accounting the precipitation. The rates of AET were calculated for each day of the study period. Temperature fluctuated between 17.2 and 23.3 °C and total rainfall was 43.76 mm. AET rates from 0.6 to 6.9 mm day−1 were recorded, with a ΣAET/ΣP ratio of 1.38. The estimated potential ET (PET) resulting from Thornthwaite's semi-empirical formula suggested values between 2.8 and 3.9 mm day−1. The average AET/PET ratio was 1.13. According to the literature, the results obtained are plausible. This system, relatively inexpensive and simple to install, may eventually be used to calculate AET on peaty soils in the years to come.

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Minimizing carbon loss through integrated water resource management on peatland utilization in Pulau Burung, Riau, Indonesia

E3S Web of Conferences ◽

10.1051/e3sconf/202020002019 ◽

2020 ◽

Vol 200 ◽

pp. 02019

Author(s):

Nurul Ihsan Fawzi ◽

Annisa Noyara Rahmasary ◽

Ika Zahara Qurani

Keyword(s):

Water Management ◽

Resource Management ◽

Water Resource ◽

Water Table ◽

Water Resource Management ◽

Peat Soil ◽

Carbon Loss ◽

Integrated Water Resource Management ◽

Subsidence Rate ◽

Yearly Average

Sustainable utilization of peatland is required for balancing production and conservation efforts. On peatland, one of the main components to examine sustainability is understanding the carbon balance. This research was conducted in Pulau Burung, Riau, Indonesia, which has a long history of peatland utilization for agriculture. The sets of utilized data included historical data of water management on peatland represented by water table and subsidence rate, next to carbon density of peat soil. The results showed the function of integrated water resource management made the yearly average water table depth is 48 and 49 cm in 2018 and 2019, respectively. The range water table is between 31cm to 72 cm due to season variability and crop requirement. Consequently, the rate of annual subsidence is averaging at 1.7 cm with cumulative subsidence in 32 yr is 54.1 cm. Since the water never drained since the establishment, the subsidence rate of the first five years is averaging only at 3.3 cm yr–1. Low subsidence rates minimize annual carbon loss during the peatland utilization around (30 to 200) Mg CO2 ha–1 yr–1. In 32 yr, the water management in peatland utilization in Pulau Burung has prevented 2 000 Mg CO2 ha–1 to 4 925 Mg CO2 ha–1 loss compared to other cultivated areas in peatland. Further, this paper discusses the practice that resulted in low emission of coconut agriculture in Pulau Burung as one of sustainability dimensions, which support the other sustainability aspects, that is the thriving local livelihood.

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