The drivers of plant community composition have shifted from external to internal processes over the past 20,000 years
Permanent lenke
https://hdl.handle.net/10037/29960Dato
2023-05-19Type
Journal articleTidsskriftartikkel
Peer reviewed
Sammendrag
Internal and external factors regulating the past composition of plant communities are difficult to identify in palaeo-vegetation records. Here, we develop an index of relative entropy of
community assembly, which applies to changes in the composition of a community over time,
measuring disorder in its assembly relative to disassembly. Historical periods of relatively
ordered assembly (negative index values) are characteristic of a community undergoing
endogenous self-organisation, in contrast to relatively disordered assembly (positive values)
characterising periods of exogenous abiotic forcing. We quantified the relative entropy index
for a 22,000-year time-series of tundra vegetation obtained in the Polar Urals, based on
sedimentary DNA. We find it most positive during the Late Pleistocene characterized by
persistent taxa, and most negative during the post-glacial Holocene characterized by more
ephemeral floras. Changes in relative entropy coincide with changes in regional temperature
as reconstructed from stable oxygen composition of an Arctic ice-core. Our results suggest
that temperature strongly influenced community assembly in the Polar Urals until about
9000 years before present, after which endogenous community self-organization prevailed
through to the present. We conclude that time-series of community composition can reveal
changes in the balance between internal and external influences on taxonomic turnover and
resulting diversity.
Forlag
Springer NatureSitering
Doncaster, Edwards, Clarke, Alsos. The drivers of plant community composition have shifted from external to internal processes over the past 20,000 years. Communications Earth & Environment. 2023;4(1)Metadata
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