Extent and timing of floristic exchange between Australian and Asian rain forests
Extent and timing of floristic exchange between Australian and Asian rain forests
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DOI：
10.1111/j.1365-2699.2011.02519.x
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发表时间：
2011-08-01
影响因子：
3.9
通讯作者：
Jordan, Gregory J.
中科院分区：
文献类型：
--
作者：
Sniderman, J. M. Kale;Jordan, Gregory J.
目的我们测试了一个根深蒂固的概念-澳大利亚雨林植物群基本上是冈瓦纳的遗迹。我们还评估了该植物群的组装区域水平的源汇动态的作用。位置东Australia.Methods为了避免潜在的偏见固有的选择性研究进行到目前为止，我们使用了分析，整体的植物群的方法与化石记录相结合。我们确定了木本澳大利亚热带雨林植物类群和其他土地上的亲戚之间的分离。为了测试该植物群的区域古老性的化石证据的强度，我们评估了在澳大利亚化石记录中代表的这些间断分支的比例，并将该记录中的偏差的影响降到最低，我们比较了晚第四纪（即晚更新世和全新世，126-0 ka），上新世和晚渐新世-早中新世澳大利亚花粉记录解释为热带雨林。使用种内分离作为代理，我们评估了最近从亚洲到澳大利亚的移民的作用。要评估的源-汇动态的作用，我们进行了比较分析的主要雨林类别代表南北/climate gradient.Results的脱节，澳大利亚南部，冷温带（微热）雨林包含许多植物区系的脱节与冈瓦纳碎片和大多数这些分支冈瓦纳化石。澳大利亚温带雨林中的间断分支大多发生在亚洲/马来西亚，这些分支中的一小部分显示出前新第三纪的记录。许多分支在低地热带和'干燥'雨林显示与亚洲/Malaysia的分离，很少有澳大利亚的化石记录。在这些北方森林中，最近来自亚洲/马尔代夫的移民率很高，大约是最近移民率的九倍。晚第四纪化石记录有更多的雨林被子植物比渐新世-中新世和上新世植物群，广泛的晚新生代immigration.Main conclusions一致的低温雨林主要是冈瓦纳遗骨，但有逐步更大，更近的贡献，从亚洲/Maleanus到更多的北方，更多的低地热带雨林。这种变化反映了强烈的梯度，这些森林和源植物区系在亚洲/马来西亚之间的地理和生态接近，并与移民的源-汇大小模型驱动的晚新生代收缩和澳大利亚雨林的扩张是一致的。
Aim We tested an entrenched concept - that the Australian rain forest flora is essentially a Gondwanan relict. We also assessed the role of regional-level source-sink dynamics in the assembly of this flora.Location Eastern Australia.Methods To avoid potential biases inherent in selective studies undertaken to date, we used an analytical, whole-of-flora approach integrated with the fossil record. We identified disjunctions between woody Australian rain forest plant taxa and relatives on other land masses. To test the strength of the fossil evidence for the regional antiquity of this flora, we evaluated the proportion of these disjunct clades represented in the Australian fossil record, and to minimize the effects of biases in this record, we compared late Quaternary (i.e. late Pleistocene and Holocene, 126-0 ka), Pliocene and late Oligocene-early Miocene Australian pollen records interpreted as tropical rain forest. Using within-species disjunctions as a proxy, we assessed the role of recent immigration from Asia into Australia. To assess the role of source-sink dynamics, we performed comparative analyses of disjunctions in major rain forest categories representing a north-south/climatic gradient.Results Southern Australian, cool temperate (microthermal) rain forests contain many floristic disjunctions with Gondwanan fragments and most of these clades have Gondwanan fossils. Disjunct clades in Australian mesothermal rain forest mostly occur in Asia/Malesia and a low proportion of these clades show pre-Neogene records. Many clades in lowland tropical and 'dry' rain forest show disjunctions with Asia/Malesia and few have Australian fossil records. Rates of recent immigration from Asia/Malesia are high in these northern forests, and outweigh rates of recent emigration approximately nine-fold. The late Quaternary fossil record has many more rain forest angiosperms than Oligocene-Miocene and Pliocene floras, consistent with extensive late Cenozoic immigration.Main conclusions The microthermal rain forests are largely Gondwanan relicts, but there is progressively greater, and more recent contribution from Asia/Malesia into more northern, and more lowland tropical rain forests. This variation reflects a strong gradient in geographic and ecological proximity between these forests and source floras in Asia/Malesia, and is consistent with a source-sink size model of immigration driven by late Cenozoic contractions and expansions of Australian rain forest.