Global diversity patterns of larger benthic foraminifera under future climate change

Global warming threatens the viability of tropical coral reefs and
associated marine calcifiers, including symbiont-bearing larger benthic
foraminifera (LBF). The impacts of current climate change on LBF are
debated because they were particularly diverse and abundant during past
warm periods. Studies on the responses of selected LBF species to changing
environmental conditions reveal varying results. Based on a comprehensive
review of the scientific literature on LBF species occurrences, we applied
species distribution modeling using Maxent to estimate present-day and
future species richness patterns on a global scale for the time periods
2040–2050 and 2090–2100.  For our future projections, we focus on
Representative Concentration Pathway 6.0 from the Intergovernmental Panel
on Climate Change, which projects mean surface temperature changes of
+2.2°C by the year 2100. This data set comprises all raw data and results.
Our results suggest that species richness in the Central Indo-Pacific is
two to three times higher than in the Bahamian ecoregion, which we have
identified as the present-day center of LBF diversity in the Atlantic. Our
future predictions project a dramatic temperature-driven decline in
low-latitude species richness and an increasing widening bimodal
latitudinal pattern of species diversity. While the central Indo-Pacific,
now the stronghold of LBF diversity, is expected to be most pushed outside
of the currently realized niches of most species, refugia may be largely
preserved in the Atlantic. LBF species will face large-scale non-analogous
climatic conditions compared to currently realized climate space in the
near future, as reflected in the extensive areas of extrapolation,
particularly in the Indo-Pacific. Our study supports hypotheses that
species richness and biogeographical patterns of LBF will fundamentally
change under future climate conditions, possibly initiating a faunal
turnover by the late 21st century.