H.S., Arathi .
Contrasting seed dispersal traits in urban and 'mainland' populations of the common dandelion, Taraxacum officinale.
For successful dispersal, plant seeds must land on suitable surfaces. Increased urbanization and habitat fragmentation have resulted in such sites becoming smaller and creating isolated ‘urban islands’. The common dandelion, Taraxacum officinale, grows extensively in such ‘urban islands’ although it is also found growing in large country meadows. A comparison of achenes from these two kinds of populations indicates that ‘urban island’ achenes have longer pappus shafts, correlated to a decreased airborne time, thus reducing horizontal dispersal distances. Achenes from urban dandelions however do not compromise on seed weight, a trait critical for survival. Such morphological changes affecting dispersal are known in plant populations on oceanic islands but this is the first report of a similar response in plant populations in fragmented urban landscapes. Although rapid evolution is a characteristic of successful weedy species, it remains to be seen whether this highly adaptive species of dandelions will develop secondary dispersal-related traits to enhance dispersal in fragmented urban habitats.
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1 - Colorado State University, Biology, 1878 Biology, Fort Collins, CO, 80523, USA
Presentation Type: Poster:Posters for BSA Sections
Location: Event Tent/Cliff Lodge
Date: Tuesday, July 28th, 2009
Time: 5:30 PM