The potential implication of VOCs for Tropical Peatland accumulation in the Congo Basin

The inherent conditions of tropical peatlands contradict their existence, since the hot and humid climate typically promotes decomposition in a way which would prevent the accumulation of organic matter. There is understood to be some factor(s) operating which inhibits the activities of decomposing bacteria and fungi to allow the preservation of organic matter and hence the development of peatlands. VOCs are instrumental in mediating belowground microbial interactions as allelochemicals for bacteria and fungi. There is a growing body of literature which reports VOCs exercising an antagonistic effect on microbes to inhibit their activity, thereby supressing decomposition and decay processes. Using SPME/GC-MS to extract and identify compounds from plant and peat material from the recently discovered and pristine Congo Basin peatlands, a total of 89 VOC compounds were identified. Of these, 59 had been studied in the literature for their antimicrobial and allelopathic effects either in isolation or acting in synergy. These compounds demonstrate the ability to inhibit the breakdown of organic material in a variety of mediums. Until now, the influence and effect of VOCs on decomposition processes has been overlooked and should in future be considered for their potential positive impact on peatland accumulation processes. Their presence could provide a mechanism to account for the existence of tropical peatlands, particularly those that are close to the climatic limits for peat formation.