Fossil Floras and Glacial Periods
نویسندگان
چکیده
منابع مشابه
Relationships between leaf morphology and climate, Bolivia: implications for estimating paleoclimate from fossil floras
—Fossil floras are an important source of quantitative terrestrial paleoclimate data. Many paleoclimate estimates are based on relationships observed in modern vegetation between leaf morphology and climate, such as the increase in the percentage of entire-margined species with increasing temperature and the increase in leaf size with increasing precipitation. An important question is whether t...
متن کاملAtmospheric depletion of mercury over Antarctica during glacial periods
Mercury is a globally dispersed toxic metal that affects even remote polar areas. During seasonal atmospheric mercury depletion events in polar areas, mercury is removed from the atmosphere1,2 and subsequently deposited in the surface snows3. However, it is unknown whether these events, which have been documented for the past two decades, have occurred in the past. Here we show that over the pa...
متن کاملVariation in periodontal floras.
Statistical analyses indicated (i) that the floras of individual samples taken from the depth of sulci with nickel-plated Morse 00 scalers were highly reproducible and representative of the flora present at any given time, (ii) that the different compositions of floras of different people with similar clinical signs were statistically highly significant, and (iii) that floras of different affec...
متن کاملMolecular fossil evidence for anaerobic ammonium oxidation in the Arabian Sea over the last glacial cycle
[1] Anaerobic ammonium oxidation (anammox) has been recognized as an important process converting fixed nitrogen to N2 in many marine environments, thereby having a major impact on the present-day marine nitrogen cycle. However, essentially nothing is known about the importance of anammox in past marine nitrogen cycles. In this study, we analyzed the distribution of fossil ladderane lipids, der...
متن کاملIncreased dust deposition in the Pacific Southern Ocean during glacial periods.
Dust deposition in the Southern Ocean constitutes a critical modulator of past global climate variability, but how it has varied temporally and geographically is underdetermined. Here, we present data sets of glacial-interglacial dust-supply cycles from the largest Southern Ocean sector, the polar South Pacific, indicating three times higher dust deposition during glacial periods than during in...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nature
سال: 1877
ISSN: 0028-0836,1476-4687
DOI: 10.1038/016067a0