Search results for "Tropical marine climate"
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Tropical marine climate during the late Paleozoic ice age using trace element analyses of brachiopods
2009
Abstract The late Paleozoic ice age can be considered an important analogue to the modern ice age, but comparisons between the two time intervals have been hampered by the difficulty of resolving climatic changes that occur over short (e.g., seasonal) time scales in the Paleozoic record. As a first step toward overcoming these limitations, this study employed Mg/Ca trace element ratios sampled across the growth bands of six specimens of the brachiopod Composita to assess differences in tropical marine mean temperature and seasonality in Visean and Moscovian time. These time intervals bracket the onset of the late Paleozoic ice age, which occurred in mid-Serpukhovian time, and thus provide a…
Interspecific-Competition Strongly Constrains Species-Richness and Species-Abundance Evenness in a Tropical Marine Molluscan Community Inhabiting Cau…
2021
Increasing species-richness at the local scale (within species communities) is accommodated, first, by the diversification of the niches respectively associated to species. Yet, in case of excessive supply in colonizing species issued from the regional pool, the corresponding increase in the number of solicited niches may lead to some “niche-overcrowding” resulting in significant niche-overlaps. Then, second, strong interspecific competition for shared resource can arise, triggered by the density in individuals among those species co-occurring at niche-overlaps. Accordingly, the accommodation of species-richness within a local community involves a balance between (i) the positive contributi…