Biology subjects

Pestryakova, L.

Publications and source records attributed to Pestryakova, L..

2 recordsLinked to original sources

bioRxiv2021

Long-term fungus-plant co-variation from multi-site sedimentary ancient DNA metabarcoding in Siberia

Climate change has a major impact on arctic and boreal terrestrial ecosystems as warming leads to northward treeline shifts, inducing consequences for heterotrophic organisms associated with the plant taxa. To unravel ecological dependencies, we address how long-term climatic changes have shaped the palaeo-ecosystems at selected sites in Siberia. We investigated sedimentary ancient DNA from five lakes spanning the last 47,000 years, using the ITS1 marker for fungi and the chloroplast P6 loop marker for vegetation metabarcoding. After bioinformatic processing with the OBItools pipeline, we obtained 706 unique fungal operational taxonomic units (OTUs) and 243 amplicon sequence variants (ASVs) for the plants. We show higher OTU numbers in dry forest tundra as well as boreal forests compared to wet southern tundra. The most abundant fungal taxa in our dataset are Pseudeurotiaceae, Mortierella, Sordariomyceta, Exophiala, Oidiodendron, Protoventuria, Candida vartiovaarae, Pseudeurotium, Gryganskiella fimbricystis, and Trichosporiella cerebriformis. The overall fungal composition is explained by the plant composition as revealed by redundancy analysis. The fungal functional groups show antagonistic relationships in their climate susceptibility. The advance of woody taxa in response to past warming led to an increase in the abundance of mycorrhizae, lichens, and parasites, while yeast and saprotroph distribution declined. We also show co-occurrences between Salicaceae, Larix, and Alnus and their associated pathogens and detect higher mycorrhizal fungus diversity with the presence of Pinaceae. Under future warming, we can expect feedbacks between fungus compositional and plant diversity changes which will affect forest advance and stability in arctic regions.

ecology↗

bioRxiv2020

Plant sedimentary ancient DNA from Far East Russia covering the last 28 ka reveals different assembly rules in cold and warm climates

Woody plants are expanding into the Arctic under a warming climate. The related impact on plant diversity is not well understood because we have only limited knowledge about plant assembly rules and because of a lack of time-series of plant diversity. Here, we applied sedimentary ancient DNA metabarcoding using the plant-specific g and h primers of the trnL gene to a sediment record from Lake Ilirney (central Chukotka Far Eastern Russia) covering the last 28 thousand years. Our results show that forb-dominated steppe-tundra and Saliceae-rich dwarf-shrub tundra communities dominated during the cold climate before 14 ka, while deciduous erect-shrub tundra was abundant during the warm period between 14 and 0 ka. Larix invasion during the late Holocene substantially lagged behind the period of densest vegetation and likely warmest period between 10 and 6 ka. Overall, we discovered the highest richness during 28-23 ka and a second richness peak during 13-10 ka: both periods are characterised by low shrub abundance. The richest communities during the cold pre-14 ka period were phylogenetically clustered, which probably originates from environmental filtering along with niche differentiation under limited resources. In contrast, the richest post-14 ka community was phylogenetically overdispersed, likely originating from an erratic recruitment process in the course of warming. Despite differences in timescale, some of our evidence can be relevant to arctic plant diversity changes. By analogy to the past, we expect a lagged response of tree invasion. In the long-term, ongoing expansion of deciduous shrubs will eventually result in a phylogenetically more diverse community but will also cause reduced plant taxonomic richness; however, richness may overshoot in the short-term.

ecology↗