Re: Do deciduous trees annually lose their leaves regardless of climate?

Yes. In tropical climates some trees are deciduous even though there are no 
freezing temperatures. However, there are often wet and dry seasons so trees 
tend to lose leaves before the dry season.

In the US, some species have a very wide north-south distribution. For example, 
flowering dogwood (Cornus florida) is native from Florida to Maine but is 
deciduous everywhere. In temperate areas, the daylength varies throughout the 
year and enables plants to detect when fall is approaching, thereby triggering 
leaf drop in deciduous species. Some trees, such as sweetbay (Magnolia 
virginiana) are nearly evergreen in the southern US but fully deciduous in the 
northern US.