Soil Microbial Communities in Southeast Asian Peatlands: A Review

Peatlands in Southeast Asia are considered biodiversity hotspots that contribute significantly to the global carbon cycle. Land-use change on these tropical peatlands alters chemical and physical properties of the peat which directly affect plant health and the composition, diversity and functioning of soil microbial communities. Soil microbial diversity in tropical peatlands is considerably less understood than in boreal peatlands. The aim of this study was to investigate published English-language literature on soil microbial communities in the peatlands of Indonesia, Malaysia and Brunei using a systematic quantitative literature review approach, focusing on their fungal, bacterial and archaeal soil or rhizosphere communities. Data extracted from the articles (published between 2001 and 2023) included the study location, peatland condition, peat depth, context of the research, soil microbial communities and microbial functions studied, and soil abiotic processes assessed. We found 75 studies that met the review criteria, of which the majority (45) were from Indonesia, 29 from Malaysia and one from Brunei. Soil bacteria were reported in 43 % compared to soil fungi in 32 % of these studies. Both bacteria and fungi were reported in 17 % of studies, while only 8 % of studies reported archaea, bacteria and fungi. Soil microbial functions were assessed in 52 % of studies, with considerable emphasis on enzyme activity, respiration and decomposition. Agriculture was the most common research focus (29 % of studies), followed by biodiversity (23 %) and forestry (8 %). Many studies integrated microbial richness and diversity metrics with putative functional attributes, which is an important step towards better understanding microbial activity in peatlands. Future challenges involve better understanding soil archaeal and fungal communities in Southeast Asian peatlands and the roles that they play in peatland ecosystem processes.