Shallow Soil and Tall Trees?

Today's Partial Track (via APRS)
A More Accurate Track via PlotaRoute

The last couple days I haven't really looked forward to a trike ride but it's kind of a tradition and even when my mood is lacking I always feel better when pedaling roundabout.
Today was no exception.  It was quite cold all day, with a HIGH of around 51 degrees and stiff COLD wind.  I wore 3 layers of shirt:  A "normal" short sleeve shirt underneath,  one of Jacque's homemade flannel shirts on top of that, and my nylon yellow visibility jacket on the outside.  I did NOT get overheated, and barely stayed warm enough on most of the ride.
I wanted to get in a few more miles than my too-usual 5-ish mile runs.  So I took off toward the airport and south on Bell Crossing Road from there.  I faintly remember riding this area before and finding a paved return route somewhere out there, but the closest cross road I came to was Sunshine, and that immediately turned to gravel, which I detest.  So I turned around and retraced my route all the way back.
Along the way, I again noticed the really TALL trees lining the roadway.  The soil around here is not deep at all;  a couple feet of soil shows in the road cuts, atop layers of limestone.  Yet most of the trees get super tall.

Many of such trees are over 100 feet high... It's a wonder they all don't blow over when the winds get high.  Some do.  Maybe they have taproots that penetrate the shallow soil and through the layers of limestone to some depth.
One slight problem cropped up on this ride.  I turned the brakes loose going down a long hill (thus the 29+ MPH reading), I bounced over several large pavement ruts and bumps, and suddenly the GPS bleeped and said something about needing external power.  I looked at the radio/GPS cluster closer and realized the Kenwood walkie-talkie was dead, without power, and thus the GPS had complained because it was now running on it internal battery.  I checked and re-checked the various DC connection leading from the Lithium-Ion battery in the saddlebag and the radios and could find nothing wrong.  Starting to ride again, I thought suddenly about the actual connectors ON the battery inside the saddlebag.  It took a bit of digging to get it out, but sure enough, one of the spade connectors had popped loose during all the road-bouncing.  I don't think I've ever seen that happen before... But it's always something.

Ride Started:    3:44 PM      Ride Ended:  5:01 PM
Beginning Battery Voltage:  13.9  Ending Battery Voltage:  13.0   Lowest Voltage:  13.0

Beginning Blood Glucose:  111      Ending BG: 89

Lowest Temp:  57 F    Highest Temp:  64  F

Stats from the GPS:  Total Miles:   7.64
Distance Walked: .6 mile
Overall Average Speed       Moving Avg          Max Speed
  5.9 MPH                             6.8 MPH               29.3 MPH (Downhill w/Tailwind!)

Total Trip Time                   Moving Time        Stopped  Time
 1 hour 17 mins                  1 hour 7 mins         10 minutes