TY - JOUR
T1 - Planktonic foraminiferal response to the latest Maastrichtian abrupt warm event
T2 - A case study from South Atlantic DSDP Site 525A
AU - Abramovich, Sigal
AU - Keller, Gerta
N1 - Funding Information:
We thank the reviewers Alexandra Nederbragt and Stephen Culver for their comments, suggestions and encouragement. We thank Zsolt Berner and Doris Stüben for analysis of stable isotopes. Samples from DSDP Site 525A were provided by the Ocean Drilling Program. This study was supported by BSF Grant 98 00425.
PY - 2003/7
Y1 - 2003/7
N2 - An abrupt global warming of 3-4°C occurred near the end of the Maastrichtian at 65.45-65.10 Ma. The environmental effects of this warm event are here documented based on stable isotopes and quantitative analysis of planktonic foraminifera at the South Atlantic DSDP Site 525A. Stable isotopes of individual species mark a rapid increase in temperature and a reduction in the vertical water mass stratification that is accompanied by a decrease in niche habitats, reduced species diversity and/or abundance, smaller species morphologies or dwarfing, and reduced photosymbiotic activity. During the warm event, the relative abundance of a large number of species decreased, including tropical-subtropical affiliated species, whereas typical mid-latitude species retained high abundances. This indicates that climate warming did not create favorable conditions for all tropical-subtropical species at mid-latitudes and did not cause a massive retreat in the local mid-latitude population. A noticeable exception is the ecological generalist Heterohelix dentata Stenestad that dominated during the cool intervals, but significantly decreased during the warm event. However, dwarfing is the most striking response to the abrupt warming and occurred in various species of different morphologies and lineages (e.g. biserial, trochospiral, keeled globotruncanids). Dwarfing is a typical reaction to environmental stress conditions and was likely the result of increased reproduction rates. Similarly, photosymbiotic activity appears to have been reduced significantly during the maximum warming, as indicated by decreased δ13C values. The foraminiferal response to climate change is thus multifaceted resulting in decreased species diversity, decreased species populations, increased competition due to reduced niche habitats, dwarfing and reduced photosymbiotic activity.
AB - An abrupt global warming of 3-4°C occurred near the end of the Maastrichtian at 65.45-65.10 Ma. The environmental effects of this warm event are here documented based on stable isotopes and quantitative analysis of planktonic foraminifera at the South Atlantic DSDP Site 525A. Stable isotopes of individual species mark a rapid increase in temperature and a reduction in the vertical water mass stratification that is accompanied by a decrease in niche habitats, reduced species diversity and/or abundance, smaller species morphologies or dwarfing, and reduced photosymbiotic activity. During the warm event, the relative abundance of a large number of species decreased, including tropical-subtropical affiliated species, whereas typical mid-latitude species retained high abundances. This indicates that climate warming did not create favorable conditions for all tropical-subtropical species at mid-latitudes and did not cause a massive retreat in the local mid-latitude population. A noticeable exception is the ecological generalist Heterohelix dentata Stenestad that dominated during the cool intervals, but significantly decreased during the warm event. However, dwarfing is the most striking response to the abrupt warming and occurred in various species of different morphologies and lineages (e.g. biserial, trochospiral, keeled globotruncanids). Dwarfing is a typical reaction to environmental stress conditions and was likely the result of increased reproduction rates. Similarly, photosymbiotic activity appears to have been reduced significantly during the maximum warming, as indicated by decreased δ13C values. The foraminiferal response to climate change is thus multifaceted resulting in decreased species diversity, decreased species populations, increased competition due to reduced niche habitats, dwarfing and reduced photosymbiotic activity.
KW - Climate change
KW - Late Maastrichtian
KW - Planktonic foraminifera
UR - http://www.scopus.com/inward/record.url?scp=0038348478&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0038348478&partnerID=8YFLogxK
U2 - 10.1016/S0377-8398(03)00021-5
DO - 10.1016/S0377-8398(03)00021-5
M3 - Article
AN - SCOPUS:0038348478
SN - 0377-8398
VL - 48
SP - 225
EP - 249
JO - Marine Micropaleontology
JF - Marine Micropaleontology
IS - 3-4
ER -