Phytogeography and Floral Diversity of the Namurian and Westphalian A (Carboniferous)

在中石炭世，南半球开始了大陆冰川作用，海洋动物群遭受灭绝事件，陆地植物辐射。冰川当然会导致高纬度的降温；它们也可能改善(温暖和潮湿)赤道气候。海洋动物群和陆地植物群对冰川作用的不同响应可能与它们对赤道改善的不同反应有关。冰川开始期间这种改善的证据来自对气候敏感的沉积物和动物迁徙。如果中石炭世冰川作用改善了陆地上的赤道气候：1，冰期前，季节性适应，赤道植物应该已经从赤道迁移到中低纬度地区；2，赤道带冰川作用后，赤道地区的起源速率应该增加；中石炭世陆地植物的辐射应该集中在赤道地带。有关植物镜面的数据将建立中石炭世的陆地古气候历史。关于植物在这段时间内纬度多样性梯度变化的数据将记录这段历史。关于中石炭世植物的多样性和进化率(起源和灭绝)的全球、花界和纬度的数据将表明中石炭世植物辐射是否集中在赤道地带。对中石炭世植物地理学的研究将有助于评估生物多样性、生物地理分化和极地至赤道气候梯度之间的联系。

During the middle Carboniferous, continental glaciation began in the Southern Hemisphere, marine faunas suffered an extinction event, and land plants radiated. Glaciations certainly cause high-latitude cooling; they may also ameliorate (warm and moisten) equatorial climates. The differing responses of marine faunas and land floras to glaciation may relate to their differing responses to equatorial amelioration. Evidence for this amelioration during glacial onset comes from climatically-sensitive sediments and faunal migrations. If mid-Carboniferous glaciation ameliorated equatorial climates on land: 1, pre-glacial, seasonally adapted, equatorial plants should have migrated away from the equator into the low and middle latitudes; 2, the equatorial zone should have experienced increased origination rates following glaciation; the mid-Carboniferous radiation of land plants should have been centered on the equatorial zone. Data on floral mirgrations will establish the terrestrial paleoclimatic history of the mid- Carboniferous. Data on changes in the latitudinal diversity gradient of plants during this interval will carroborate that history. Data on the diversity and evolutionary rates (origination and extinction) of mid-Carboniferous plants, globally, within floral realms, and latitudinally, will indicate whether the mid-Carboniferous floral radiation was centered on the equatorial zone. A study of mid-Carboniferous phytogeography will allow evaluation of the link between biotic diversity, biogeographic differentiation and the pole-to-equator climatic gradient.