Pennsylvanian coniferopsid forests in sabkha facies reveal the nature of seasonal tropical biome
Pennsylvanian coniferopsid forests in sabkha facies reveal the nature of seasonal tropical biome
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DOI：
10.1130/g31764.1
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发表时间：
2011-04
期刊：
影响因子：
5.8
通讯作者：
H. Falcon-Lang;N. Jud;W. Nelson;W. DiMichele;D. Chaney;S. Lucas
中科院分区：
文献类型：
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作者：
H. Falcon-Lang;N. Jud;W. Nelson;W. DiMichele;D. Chaney;S. Lucas
宾夕法尼亚化石森林在热带盘古大陆的数百个地点已知，但几乎所有都是潮湿的煤炭森林的遗迹。在这里，我们报告了一种独特的季节性干燥植被，保存在美国新墨西哥州宾夕法尼亚期(密苏里早期卡西莫万)沿5公里走向的生长位置。对树桩解剖、直径和空间密度的分析，以及对维管束和相关大绿叶植物的观察，表明这是一片落叶、混龄、针叶林地(∼每公顷100棵树)，树冠开阔。针叶藻类在沿海萨布卡相定居，并显示树木年轮，证实了在季节性干燥条件下的生长。这样的林地可能是针叶足类的来源，在更干燥的气候阶段，针叶树在盘古大陆中部更东边的地方取代了煤炭森林。因此，新发现的林地有助于解开生物群规模的植被动态，并允许校准气候模型。
Pennsylvanian fossil forests are known from hundreds of sites across tropical Pangea, but nearly all comprise remains of humid Coal Forests. Here we report a unique occurrence of seasonally dry vegetation, preserved in growth position along >5 km of strike, in the Pennsylvanian (early Kasimovian, Missourian) of New Mexico (United States). Analyses of stump anatomy, diameter, and spatial density, coupled with observations of vascular traces and associated megaflora, show that this was a deciduous, mixed-age, coniferopsid woodland (∼100 trees per hectare) with an open canopy. The coniferopsids colonized coastal sabkha facies and show tree rings, confirming growth under seasonally dry conditions. Such woodlands probably served as the source of coniferopsids that replaced Coal Forests farther east in central Pangea during drier climate phases. Thus, the newly discovered woodland helps unravel biome-scale vegetation dynamics and allows calibration of climate models.