In addition to environmental interests, tropical peatlands also have the potential to be developed into natural recreational parks.
Field work location in Muara Siran village (Google Maps, 2019)
On the first week of April 2018, our research team conducted field work for a week in order to collect peat sample from one peatland in Kalimantan. The team consists of one professor from Geological Engineering Department and four student assistants. The peatland lies in the village of Muara Siran and its vicinity (Fig.1). It is part of the Kutai peatlands or Middle Mahakam Wetlands, as both are common terms used by researchers to mention wetlands in the eastern Kalimantan.
We departed from Yogyakarta to Balikpapan, the largest city in East Kalimantan. From the city, we travelled by car for about 4 hours to Samarinda, the capital of East Kalimantan, and 2.5 hour from Samarinda to Tenggarong. We passed the zig-zagging road, splayed in the anticlinorium landscape of East Kalimantan. We landed in a small harbour by the Mahakam River right at the dusk and was greeted by the magnificent sunset view. Our journey had not end yet because we still had to sail the Mahakam to reach our final destination – the Muara Siran village. We were picked up by village people from Muara Siran who drove us with small boat called “Ketinting” and sailed for around 30 minutes.
On the next day, we had our first peat-mapping day. We set off at 8 in the morning with destination is the area at the north of Lake Siran. Our typical peat-mapping always consisted of sailing the stream northward from the village, crossing the Siran Lake, following small creeks to the deeper forest, then parking our boats when the creeks end, and exploring the forest on foot. The exploring part is the real challenge, since we had to sink almost our entire feet in the murky water, try to balance ourselves, while keep moving further.
Figure 1. Peat swamp forest exploration. April 2018. (a) Sampler team with local village. (b) Sailing the Siran lake by “ketinting”. (c) One of team member’s shoe was slipped off while roaming the swamp forest. (d) Water depth in the swamp may rich adult waist. See more at http://belajargambut.ft.ugm.ac.id/2018/08/29/pengambilan-sampel-gambut
Peat sample is obtained by manual coring. This method can obtain peat sample of certain depth. Peat taken will be in form of peat core, a long half cylinder with diameter similar to auger bit diameter used. The team used MacCaulay peat sampler of Russian D corer. This auger consists of two parts: the extension bar and the auger bit which is also a container to capture peat. This auger is utilized by planting the bit into peat deposit, then rotating the bar in 180 º. This action lead the container to rotate, and simultaneously store peat inside it. This auger then lifted to release peat inside the container by opening the container flap. The length of the container is 0,5 m, thus, in one coring, peat of 0,5 m depth can be obtained. To retrieve peat of more depth, coring process must be repeated and the more extension bar must be added.
Figure 2. Peat coring. (a) The auger was planted into the deposit. (b) Extension bar was added to obtain peat of greater depth. (c) The auger was rotated in half circle to store peat below. (d) The auger consists of extension bar and auger bit which attached to container. (e) The container was opened. (f) Peat core inside the container.
Once the container is opened, peat has to be described texturally to determine its type (see article 4). Soon after it, the sample has to be packed tightly to prevent from oxygen contact, which may cause decomposition and changes in texture. Peat sample is stored inside 0,5 m-length half tube of PVC pipe, adjusting to the original form of the peat core. To fill in the empty spaces between peat sample and the tube, bubble plastic is added. This is necessary to anticipate peat getting shaken or moved during transportation. The last step is to wrap the tube as tight as possible, allowing no contact with outside air and prevent peat moisture from leaking out.
Our one-week field work was closed with a picnic in the middle of the Lake Siran. We enjoyed the perfect sunny tropical weather, some tropical fruits, and a few free jumps into the warm water. Aside from its various environmental importance, tropical peatlands also bear potential to be developed into a natural recreation park. This is topped with the hospitality of the villagers of Muara Siran we experienced during our stay.
Figure 3. My friend, floating and sun-bathing on the lake.
At last, we headed home in the 8th day with all our peat samples. Our field work as a first-time experience for all teammates and surely, an unforgettable one. However, our research journey is yet to end, as two big containers of peat samples we gained need “further treatment” and more stories to reveal.
Guritno Safitri
Mahasiswi lulusan teknik Geologi tahun 2018 yang saat ini sedang melanjutkan pendidikan (Master of Science) di KU Leuven, Belgium dengan fokus ilmu Geography.
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