Re: Warm-climate autumns

["Chris Collinson" <chris_collinson@hotmail.com>]

> > Do the following plants drop their leaves with the onset of > cooler 
> weather? Do they change color (reds, yellows)? > poplars/cottonwoods 
> (Populus) [...] Yes, they do. Populus: yellow to orange or red, sometimes 
> with blackish spots. [...]
David Marjanovic wrote:
> Over here the poplars become yellow -- but there is frost every >winter, so 
> this doesn't count. In a climate without pronounced seasons plants >have 
> little reason to drop all their leaves at once, if they aren't >ill.

Plants(trees)drop their leaves in response to the shorting duration of 
daylight. Most of the time this signals the onset of winter. In thoes 
regions in which frost is rare, such as coastal areas, or non exsistant, as 
in southernly latitudes, the plants still go through the motions and 
progress through an dormant period though a much abriviated one. For the 
most part, this applies to plants which are not native to these southernly 
latitudes, or evolved further north and subsequently spread south. Plants 
native to these latidues do not drop their leaves, or do so in responce to 
different stimuli, such as a dry season.
Hope this helps.

-Chris

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