DNA metabarcoding reveals common patterns in altitudinal turnover of functional groups of fungi in Borneo and in the Andes

NOUHRA E; GEML J.

Montpellier

Congreso; 53rd ATBC 2016 annual meeting; 2016

Montane forests harbor tremendous biodiversity and high rate of endemism and provide crucial water supplies to human settlementsand agricultural areas. Fungi represent one of the largest groups of living organisms and play central roles in the functioning of terrestrialecosystems as plant symbionts, pathogens, and decomposers. Nevertheless, the vast majority of biodiversity studies have focused onvascular plants and animals and very little is known about the diversity and distribution patterns of fungi in tropical mountains.We carried out DNA metabarcoding of ITS2 rDNA from soil samples taken along multiple altitudinal gradients in the Yungas in NWArgentina and on Mount Kinabalu and in the Crocker Range in Malaysian Borneo. The sampled sites represent the all major altitudinalforest types from ca. 500 to 2500 m asl in the Yungas and from 300 to 4000 m asl in Borneo.Our deep sequence data suggests that fungal diversity is comparable across the different zonal forest types and sampling regions.However, all statistical analyses suggested that fungal community composition correlated strongly with forest type in both samplingregions, with many taxa showing strong preference for a certain elevation zone.Total fungal diversity does not appear to decrease significantly with increasing altitude, which differ markedly from patterns observedin plants and animals. Rather, different functional groups prefer certain altitudinal forest zones and such altitudinal turnover of taxaapparently does not affect substantially the total fungal richness in each zone. Several functional groups show similar distributionaltrends in Borneo and the Andes, e.g., saprotrophic fungi are more diverse at lower elevations, while root endophytes are dominantat higher altitudes. On the other hand, there are some differences in the distributional patterns of ectomycorrhizal fungi that may beexplained by the differential availability of host trees. We document strong correlations between fungal community composition andaltitudinal vegetation zones in tropical mountains, likely resulting from direct and indirect interactions, e.g., symbiotic associations,substrates for decomposing fungi, and altered environmental (microclimatic, edaphic etc.) factors. Our study offers an unprecedentedinsight into the high diversity and spatial distribution of fungi in the tropical and subtropical montane forests.