Distinctive Soil Archaeal Communities in Different Variants of Tropical Equatorial Forest

Abstract

Little is known of how soil archaeal community composition and diversity differ between local variants of tropical rainforests. We hypothesized that (1) as with plants, animals, fungi, and bacteria, the soil archaeal community would differ between different variants of tropical forest; (2) that spatially rarer forest variants would have a less diverse archaeal community than common ones; (3) that a history of forest disturbance would decrease archaeal alpha- and beta-diversity; and (4) that archaeal distributions within the forest would be governed more by deterministic than stochastic factors. We sampled soil across several different forest types within Brunei, Northwest Borneo. Soil DNA was extracted, and the 16S rRNA gene of archaea was sequenced using Illumina MiSeq. We found that (1) as hypothesized, there are distinct archaeal communities for each forest type, and community composition significantly correlates with soil parameters including pH, organic matter, and available phosphorous. (2) As hypothesized, the "rare" white sand forest variants kerangas and inland heath had lower archaeal diversity. A nestedness analysis showed that archaeal community in inland heath and kerangas was mainly a less diverse subset of that in dipterocarp forests. However, primary dipterocarp forest had the lowest beta-diversity among the other tropical forest types. (3) Also, as predicted, forest disturbance resulted in lower archaeal alpha-diversity-but increased beta-diversity in contrast with our predictions. (4) Contrary to our predictions, the BetaNTI of the various primary forest types indicated community assembly was mainly stochastic. The possible effects of these habitat and disturbance-related effects on N cycling should be investigated.

Increasing Inundation Frequencies Enhance the Stochastic Process and Network Complexity of the Soil Archaeal Community in Coastal Wetlands

“…This might be due to differences in environmental adaptations, cellular structure, and cellular metabolisms between bacteria and archaea (31)(32)(33). Our findings are consistent with those of other studies that have reported the dominant role of stochastic processes in structuring the soil archaeal communities in forests (18,43) and farmland (47). However, other studies have also revealed only a minor role of stochastic processes in governing the archaeal community assemblies in the Namib Desert (45) and in agricultural fields across eastern China (46).…”

“…Generally, the deterministic and stochastic processes are recognized to simultaneously govern the community assemblies (7,8). Extensive studies have been conducted to determine the balance between stochastic and deterministic processes governing archaeal community assembly across various ecosystems, namely, freshwater lake (20), forest (18,42,43), coastal zone (44), desert (45), and agricultural (46) ecosystems. In this study, the results of both the NCM and null model analyses suggested that unlike the deterministic process-dominated bacterial community assembly (30), soil archaeal communities are dominated by stochastic processes in coastal wetlands (Fig.…”

“…Knowledge of these process could advance our understanding on the fundamental mechanisms of establishment and maintenance of microbial diversity and allow us to decipher the responses of microbial communities to environmental changes (8,9,(15)(16)(17). Assembly processes (18)(19)(20) and co-occurrence patterns (21)(22)(23) of soil archaeal communities across various ecosystems have been extensively studied. For instance, Juottonen et al found that the archaeal communities in boreal Swedish lakes are dominated by deterministic processes (20).…”

“…For instance, Juottonen et al found that the archaeal communities in boreal Swedish lakes are dominated by deterministic processes (20). Conversely, the soil archaeal communities in tropical rainforest in Brunei Darussalam were shown to be mainly governed by stochastic processes (18). These controversial findings indicate that archaeal community assembly processes could vary across different ecosystems.…”

Effects of Escherichia pollution and salinity on nutrient levels in submerged vegetated wetlands: Insights into benthic community stability and metabolisms

“…Variation in pH (r ¼ 0.349, p , 0.01) and NO À 2 ÀN (r ¼ À0.251, p , 0.05) levels also had significant effects on the unweighted UniFrac distance of the benthic prokaryotic community, similar to previous studies (Tripathi et al 2015). This indicates that these two environmental factors may stimulate the benthic microbial community to generate turnover signals, followed by shifts in phylogenetic variation and geochemical function (Kerfahi et al 2018). In addition, under salinity stress, E. coli significantly inhibited the dominance of archaea and enhanced the dominance of bacteria (p , 0.001, Supplementary Fig.…”