DOI: 10.5061/dryad.pnvx0k6rw
title: Global biome patterns of the Middle and Late Pleistocene

description: Our primary aim was to assess the hypothesis that distinctive features of
 the patterns of vegetation change during successive Quaternary
 glacial–interglacial cycles reflect climatic differences arising from
 forcing differences. We addressed this hypothesis using 207 half-degree
 resolution global biome pattern simulations, for time slices between
 800 ka and 2 ka, made using the LPJ-GUESS dynamic global vegetation
 model. Simulations were driven using ice-core atmospheric CO2
 concentrations, Earth’s obliquity, and outputs from a pre-industrial and
 206 palaeoclimate experiments; four additional simulations were driven
 using projected future CO2 concentrations. Climate experiments were run
 using HadCM3. Using a rule-based approach, above-ground biomass and leaf
 area index of LPJ-GUESS plant functional types were used to infer each
 grid cell’s biome. The hypothesis is supported by the palaeobiome
 simulations. To enable comparisons with the climatic forcing, multivariate
 analyses were performed of global vegetation pattern dissimilarities
 between simulations. Results showed generally similar responses to
 glacial–interglacial climatic variations during each cycle, although no
 two interglacials or glacials had identical biome patterns. Atmospheric
 CO2 concentration was the strongest driver of the dissimilarity
 patterns. Dissimilarities relative to the time slice with the lowest
 atmospheric CO2 concentration show the log–linear relationship to
 atmospheric CO2 concentration expected of an index of ecocarbon
 sensitivity. For each simulation, extent and total above-ground biomass of
 each biome were calculated globally and for three longitudinal segments
 corresponding to the major continental regions. Mean and minimum past
 extents of forest biomes, notably Temperate Summergreen Forest, in the
 three major continental regions strongly parallel relative tree
 diversities, hence supporting the hypothesis that past biome extents
 played an important role in determining present diversity. Albeit that
 they reflect the climatic consequences only of the faster Earth system
 components, simulated potential future biome patterns are unlike any
 during the past 800 ky, and likely will continue to change markedly for
 millennia if projected CO2 concentrations are realised.
description: See Allen <em>et al</em>. (2020),
 Huntley <em>et al</em>. (2021) and Huntley <em>et
 al</em>. (2023): Allen, J.R.M.,
 Forrest, M., Hickler, T., Singarayer, J.S., Valdes, P.J. &
 Huntley, B. (2020). Global vegetation patterns of the past 140,000 years.
 Journal of Biogeography, 47, 2073-2090. doi 10.1111/jbi.13930
 Huntley, B., Allen, J.R.M., Forrest, M., Hickler, T.,
 Ohlemüller, R., Singarayer, J.S. & Valdes, P.J. (2021). Projected
 climatic changes lead to biome changes in areas of previously constant
 biome. Journal of Biogeography, 48, 2418-2428. doi
 10.1111/jbi.14213 Huntley, B., Allen, J.R.M.,
 Forrest, M., Hickler, T., Ohlemüller, R., Singarayer, J.S. &
 Valdes, P.J. (2023). Global biome patterns of the Middle and Late
 Pleistocene. Journal of Biogeography. doi 10.1111/jbi.14619
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