The drivers of plant community composition have shifted from external to internal processes over the past 20,000 years
The drivers of plant community composition have shifted from external to internal processes over the past 20,000 years
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 9,000 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.
Doncaster, C. Patrick
0eff2f42-fa0a-4e35-b6ac-475ad3482047
Edwards, Mary
4b6a3389-f3a4-4933-b8fd-acdfef72200e
Clarke, Charlotte
68afb5e9-7966-4b54-9549-47c49e350f6c
Alsos, Inger Greve
88244b90-b66f-4271-9064-db0544dec568
19 May 2023
Doncaster, C. Patrick
0eff2f42-fa0a-4e35-b6ac-475ad3482047
Edwards, Mary
4b6a3389-f3a4-4933-b8fd-acdfef72200e
Clarke, Charlotte
68afb5e9-7966-4b54-9549-47c49e350f6c
Alsos, Inger Greve
88244b90-b66f-4271-9064-db0544dec568
Doncaster, C. Patrick, Edwards, Mary, Clarke, Charlotte and Alsos, Inger Greve
(2023)
The drivers of plant community composition have shifted from external to internal processes over the past 20,000 years.
Communications Earth & Environment, 4 (1), [171].
(doi:10.1038/s43247-023-00834-1).
Abstract
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 9,000 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.
Text
Doncaster_et_al_2023_Commun_Earth_Environ_accepted_version (1)
- Accepted Manuscript
Text
s43247-023-00834-1
- Version of Record
More information
Accepted/In Press date: 5 May 2023
e-pub ahead of print date: 19 May 2023
Published date: 19 May 2023
Additional Information:
Funding Information:
This study was jointly supported by the Norwegian Research Council through the multinational research projects AfterIce (grant no. 213692/ F20 and 230617/ E10 to I.G. Alsos) and ECOGEN (grant no. 250963/F20 to I.G. Alsos), with a PhD studentship for C. L. Clarke provided by the UK Natural Environment Research Council (grant no. NE/L002531/1). The lake-sediment core sequence was obtained and subsequently dated via the Climate History along the Arctic Seaboard of Eurasia project (CHASE, grant. no. NRC 255415 led by J.-I. Svendsen and H. Haflidison). We thank M. K. Føreid Merkel and A.-E. Fedøy for providing assistance during sampling of the sediment cores. We thank S. Armbruster, G. A. Breed, J. A. Dearing, and D. Ehrich for commenting on earlier drafts, and G. Simpson and two anonymous reviewers for insightful and constructive criticism.
Publisher Copyright:
© 2023, The Author(s).
Identifiers
Local EPrints ID: 477380
URI: http://eprints.soton.ac.uk/id/eprint/477380
PURE UUID: 238ea22f-697e-477b-99e8-34ad2a6fdb6c
Catalogue record
Date deposited: 05 Jun 2023 16:53
Last modified: 06 Jun 2024 01:40
Export record
Altmetrics
Contributors
Author:
Charlotte Clarke
Author:
Inger Greve Alsos
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics
