[TriLUG] Really OT: maples turning yellow

[Joseph Mack NA3T]

On Wed, 3 Aug 2011, Aaron Joyner wrote:

> I'm not in the mountains proper, but at least in the 
> foothills, in Lenoir, Sawmills, Granite Falls,

just what I was looking for.

>... nothing has started to change yet.

Here you need to look for maples. Where I ride, there's not 
many maples, only one every half mile or so. I see the 
leaves on the trail and then I look up and see a tree 
turning yellow. If you were plunked down in a random piece 
of forest, you'd be unlikely to see any yellow, there are so 
few maples. If the maples were still green, I'm not good 
enough to spot a maple in half a mile of other trees.

> I doubt the temperature / water-shedding theory,

I haven't a clue myself. I was just looking for data that 
would test the photoperiod story.

On Wed, 3 Aug 2011, Alan Sterger wrote:
(with supporting evidence from  Carl Crider
and John Riselvato)

> I live in a new development, our maples have been red 
> red/orange since June. HOA called in an expert who is 
> calling it "drought stress".  They have now have water 
> bags at the base of the trees that trickle water but this 
> was done after the trees had already turned to fall colors 
> in June.

In the drought of about 4-5 yrs ago, all the trees were 
yellow/brown about now. When I saw the maples changing two 
weeks ago, my first thought was drought. However we aren't 
having a drought year. Well at least a drought year for the 
Triangle. Maybe maples like more water than they get here 
and even a regular Triangle year is drought for a maple.

The rainfall in the eastern section of Canada (which I 
assume is home for maples

hmm. The maple home turf is eastern NA centered on NY

http://en.wikipedia.org/wiki/Beech-maple_forest

) is about 800mm == 30".

http://www.eldoradocountyweather.com/canada/averageprecip.html

The average rainfall at RDU is 42"

http://www.raleigh-rdu.airports-guides.com/rdu_climate.html

and we're getting about the normal amount of rain.

http://www.wral.com/weather/page/1934052/

which is about 50% more rain than in the home territory of a 
maple.

However from the amount of water I need to drink while 
riding the last couple of weeks, compared to what I'd drink 
at 75deg, I can imagine that the current water stress on 
plants is large. Probably no amount of rain would make up 
for the heat stress. To get on well here, a plant would have 
to be heat tolerant. I imagine maples haven't been selected 
for heat tolerance and would be one of the first to suffer.

On Wed, 3 Aug 2011, John Wheeler wrote:

> My parents have a house in the northwest most county of 
> NC. google Lansing, NC, some miles west of there.
>
> They have a large maple in their front yard. Spoke with
> them moments ago and it is lush and green. They have not
> seen any other maples turning in the area either. The
> temperature there is incredibly mild in the summer, never
> feels above high 80s on the hottest summer days I can
> remember.

Why are we all doing living here then? Why isn't Raleigh in 
the mountains?

> There is generally a mild breeze that makes it
> feel a little cooler. Most summer days Hover at 73-78 F.
> Humidity doesn't linger in the air as long due to
> elevation but dew is thick on the ground every morning.

no watering the lawn or garden then.

The critical piece of data demolishing the photoperiod 
hypothesis - the maples in the mountains at the same 
latitude are happy. It must be heat and/or water. I should 
expect maples to start loosing their leaves at this time of 
year, every year, even in normal rain.

Thanks

Joe
-- 
Joseph Mack NA3T EME(B,D), FM05lw North Carolina
jmack (at) wm7d (dot) net - azimuthal equidistant map
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