Digital mapping and soil carbon stock distribution on various landuse of tropical peatland in Pesisir Selatan, West Sumatra

Abstract

Indonesia has the largest tropical peatlands in the world covered an area of 14.91 million ha. Peatlands play an important role in global carbon sequestration. This study aimed to: a] map the peatland in Pesisir Selatan, Sumatra Barat calculate the soil carbon stock in the peatlands on various land use and peat thickness and c] identify the relationship of soil characteristics to the soil carbon. We investigated thirty soil samples in Pesisir Selatan. The land-use types on peatland in Pesisir Selatan consisted of forest [GH], shrub [GS], oil palm plantations [GPs], annual cropland[GLp], and bareland [GLp]. The results showed that the total area of peatlands in Pesisir Selatan is 78,998.74 ha, while the total amount of soil carbon stocks is 244 million tonnes, and the sequence follows GPs > GS > GH > GT > GLp. The average value of soil carbon stock is 3,090.89 per ha, the sequence follows GH > GS > GT > GPs > GLp. Hence, the average amount of soil carbon stock based on depth is 8,529 tons for peat depth > 600cm, 4,082 tons for peat depth 300-600 cm, and 525 tons for peat depth 0-300 cm. Differences in average values of soil carbon stock per ha are highly influenced by the differences in peat thickness. The dynamics of total carbon show a higher its content in the subsurface layer rather than in the surface layer. The soil carbon is linearly correlated with water content and it is inversely proportional to bulk density.

Analisis Kesesuaian Lahan Untuk Pengembangan Tanaman Jagung (Zea Mays L.)

“…Zona utama wilayah Sumatera Barat umumnya dibagi menjadi 1) zona pegunungan vulkanik dan wilayah perbukitan patahan (bagian dari struktur patahan Semangko) terdapat pada bagian tengah wilyah Sumatera Barat mulai dari utara sampai selatan, 2) zona perbukitan lipatan Tersier tersebar di bagian timur wilayah Sumatra Barat dan 3) wilayah dataran rendah aluvial tersebar di pantai barat. Sebagian dataran aluvial tersebut terdapat hamparan lahan gambut seperti di Kabupaten Pesisir Selatan seluas 78.998.74 ha (Naspendra et al 2020), Agam 18.280.45 ha dan di Pasaman Barat 15.423.96 ha (BBSDLP 2013.…”

“…Tanah tersebut umumnya banyak terdapat di sekitar perbukitan lipatan tersier di bagian timur Sumatera Barat, seperti di Dharmasraya, Sijunjung, Solok Selatan, dan Pesisir Selatan. Andisol dominan terdapat di wilayah sekitar lereng pegunungan (Tan 2008, Fiantis andVan Ranst 1997), sedangkan Histosol tersebar di dataran aluvial sekitar pesisir barat (Puslittanak 1990;Naspendra et al 2020).…”