Sedimentary Ancient DNA (sedaDNA) Reveals Fungal Diversity and Environmental Drivers of Community Changes throughout the Holocene in the Present Boreal Lake Lielais Svētiņu (Eastern Latvia)

Area of Science:

• Paleoecology
• Mycology
• Environmental Science

Background:

• Fungi play crucial roles in ecosystems, but their historical dynamics in sediments are understudied.
• Understanding past fungal communities is key to reconstructing ecosystem changes.

Purpose of the Study:

• To investigate Holocene fungal community composition and ecophysiological roles in lake sediments.
• To identify fungal responses to environmental changes over 10.5 millennia.

Main Methods:

• Ancient DNA (aDNA) analysis using ITS metabarcoding on lake sediment cores.
• Reconstruction of fungal community dynamics throughout the Holocene.

Main Results:

• Diverse fungal taxa were identified with gradual community changes for most of the Holocene, followed by rapid shifts in recent millennia.
• Increased diversity of plankton parasitic fungi in the Late Holocene correlates with cooler climate shifts.
• A rise in plankton parasites, mycorrhizal, and plant pathogenic fungi in the Latest Holocene suggests increased plant material input and moderate human impact.

Conclusions:

• Fungal community shifts, especially in plankton parasites and mycorrhizal fungi, can serve as paleo-variables for ecosystem dynamics.
• Fungal aDNA analysis provides a powerful tool for reconstructing past aquatic and terrestrial ecosystems and assessing environmental change impacts.