Publication Date:
2001-09-05
Description:
Although C4 plant expansions have been recognized in the late Miocene, identification of the underlying causes is complicated by the uncertainties associated with estimates of ancient precipitation, temperature, and partial pressure of atmospheric carbon dioxide (PCO2). Here we report the carbon isotopic compositions of leaf wax n-alkanes in lake sediment cores from two sites in Mesoamerica that have experienced contrasting moisture variations since the last glacial maximum. Opposite isotopic trends obtained from these two sites indicate that regional climate exerts a strong control on the relative abundance of C3 and C4 plants and that in the absence of favorable moisture and temperature conditions, low PCO2 alone is insufficient to drive an expansion of C4 plants.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Huang, Y -- Street-Perrott, F A -- Metcalfe, S E -- Brenner, M -- Moreland, M -- Freeman, K H -- New York, N.Y. -- Science. 2001 Aug 31;293(5535):1647-51.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Geological Sciences, Brown University, Providence, RI 02912, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11533488" target="_blank"〉PubMed〈/a〉
Keywords:
Alkanes/analysis
;
Atmosphere
;
Carbon Dioxide
;
Carbon Isotopes/analysis
;
*Climate
;
*Ecosystem
;
Fossils
;
Fresh Water
;
Geologic Sediments/*chemistry
;
Guatemala
;
Mexico
;
Photosynthesis
;
*Plant Development
;
Plant Leaves/chemistry
;
Plants/metabolism
;
Poaceae/*growth & development/metabolism
;
Pollen
;
Rain
;
Seasons
;
Temperature
;
Trees/growth & development
;
Weather
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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