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

在中石炭世期间，南半球开始了大陆冰川作用，海洋动物遭受灭绝事件，陆地植物辐射。冰川作用肯定会导致高纬度地区变冷；它们还可以改善（温暖和湿润）赤道气候。海洋动物和陆地植物对冰川作用的不同反应可能与它们对赤道变暖的不同反应有关。冰期开始时这种改善的证据来自对气候敏感的沉积物和动物迁徙。如果中石炭世冰期改善了赤道陆地气候：1、冰期前，季节适应，赤道植物应该从赤道迁移到低纬度和中纬度地区；2、赤道带在冰川作用后应该经历了上升的起源率；中石炭世陆地植物的辐射应该集中在赤道地区。植物迁移的资料将建立中石炭世的陆相古气候史。在这段时间内植物的纬度多样性梯度变化的数据将证实这一历史。关于中石炭世植物的多样性和进化速率（起源和灭绝）的数据，在全球范围内，在花域内和纬度上，将表明中石炭世的花辐射是否集中在赤道地区。对中石炭世植物地理学的研究将有助于评估生物多样性、生物地理分化和两极到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.