DIASPORE MORPHOLOGY AND SEED DISPERSAL IN SEVERAL WIND-DISPERSED ASTERACEAE
DIASPORE MORPHOLOGY AND SEED DISPERSAL IN SEVERAL WIND-DISPERSED ASTERACEAE
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DOI：
10.2307/2445362
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发表时间：
1993-05-01
影响因子：
3
通讯作者：
ANDERSEN, MC
中科院分区：
文献类型：
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作者：
ANDERSEN, MC
我对19种风散菊科植物的种子进行了形态和沉降速度的测量。从形态测量，我计算雷诺数和近似羽负载的物种。一水硬铝石的沉降速度与羽流负荷的平方根成线性关系。这种关系在物种和亚科之间各不相同，但在生活史类型之间不相同。雷诺数是高度可变的亚族之间，所以在亚族内。喙瘦果的一水硬铝石有显着较低的沉降速度比与unbeaked瘦果的一水硬铝石，即使喙和unbeaked瘦果没有不同的羽负载或雷诺数。所有的一水硬铝石的雷诺数检查远高于斯托克斯定律适用的范围。我建议在研究羽流负荷和沉降速度之间的关系时，减少使用基于斯托克斯定律的公式。结果表明，许多种子性状的进化可能是由于选择的传播能力。这是尽管在形态上反映在亚科内雷诺数的相对均匀性的种类限制。
I made measurements of morphology and settling velocity on seeds of 19 species of wind-dispersed Asteraceae. From the morphological measurements I calculated Reynolds numbers and approximate plume loadings for the species. Diaspore settling velocity increases linearly with the square root of plume loading. This relationship varies among species and among subfamilies, but not among life history types. Reynolds number is highly variable among subfamilies, less so within subfamilies. Diaspores with beaked achenes have significantly lower settling velocities than diaspores with unbeaked achenes, even though beaked and unbeaked achenes do not differ in plume loading or in Reynolds number. Reynolds numbers of all diaspores examined are well above the range in which Stokes' Law applies. I recommend that the use of formulae based on Stokes' Law be curtailed in studies of the relationship between plume loading and settling velocity. The results suggest that many seed characters may have evolved due to selection on dispersal ability. This is in spite of phyletic constraints on morphology reflected in the relative uniformity of Reynolds numbers within subfamilies.