Saturday, March 25, 2017


Hi Everyone,

There's a lot of little things we saw that aren't enough for a post all by themselves, so I've put them together in this post, which I call leftovers.

Leftover 1.  At the Gulf State Park, AL campground, we walked through a long-leaf yellow pine restoration area.  The kiosk said that when Europeans first arrived, there were over 90 million acres of long-leaf yellow pine forest.  Now, there is just 2.9.  The long-leaf yellow pines are excellent timber for building just about anything, and the tall pines were  used for sailing ship masts and the trees were also utilized as a source of turpentine (a paint solvent), before the introduction of mineral spirits. By 1932 the extensive forest ecosystem had largely collapsed.  The ecosystem was further harmed by preventing fires, a necessary factor that you've seen as beneficial to other species in earlier blog posts.  I guess
Smokey the Bear was pretty effective, but maybe not as beneficial as he thought.

During and after Hurricane Katrina, wind and saltwater damaged about 65 percent of the loblolly pine forest in the park.  So, managers began a project to foster the growth of the yellow pine ecosystem, which fared better in the hurricane.  This has included salvaging the downed timber, herbiciding competing species, prescribed burning, and replanting.  They expect it to take many years for the forests to provide the benefits of an intact ecosystem, which includes providing habitat for such species as bobwhite quail, gopher tortoise, white tailed deer, eastern king snakes, wild turkey, fox squirrels, and others.  Here's the trail through the re-established forest at twilight.

Leftover 2.  If there's one thing I've learned in this trip, its that the world is a place of contrasts.  Here's a beautiful tree tunneled road in Chalmette, LA....

About 500 feet from this humongous Valero refinery.  Each refinery we passed seemed to be ringed first by single-wide mobile homes, then a ring of more expensive double-wides, then a ring of duplex / rental properties, and then when you were far enough away, more expensive single family homes.

Leftover 3.  We went for a walk on a wildlife trail at the St. Bernard State Park.  We saw these interesting mud tubes, which are made by crawfish (or crawdads or crayfish, depending on where you are from).  We hadn't seen these before.  A ranger explained that the crawfish dig into the mud to feed.  The water table here is very close to the surface, so even though this is "dry" ground, the crawfish are still in their aquatic habitat.  This also provides them with protection from predation. The hole is about an inch or inch and a quarter in diameter, the tube is about 4 - 5 inches high.

The trail was beautiful, with very few mosquitoes, even though we were surrounded by water and wet places.  It smelled wonderful, and there was a wonderful spring warmth in the breeze.  Not too hot, not too cold, just right....

These are the Eastern Lubber Grasshopper Nymphs.  The nymphs are apparently gregarious, and come together in the evening to colonize in clumps.  This species is a pest for gardeners - adults are about 3 inches long.

This owl was hooting for quite a long time before we were lucky enough to spot him.  Prof.s McDonald and Parshall would know better than me, but I believe its a Barred Owl.

Leftover 4.  This is Walter F. George Reservoir, on the Chattahoochee River in Georgia, downstream of Atlanta.  One of the campgrounds we stayed at was in Florence Marina State Park, located on the lakeshore.  I worked for just under eight years as a contract employee to the US Army Corps of Engineers monitoring water quality, remediating the impacts of dams, and doing water quality data analysis.

Once, we did a cool project on West Point Lake, one of the Chattahoochee lakes just upstream of this one.  This was in the very early 90's, when GPS was a very new thing, and the signal from GPS's was scrambled so foreign governments could not use the signal to accurately pinpoint missile strikes. At the time, the best scientists could do to correct for this scramble was to use two GPS units (at the time they were the size of a large desktop computer or a suitcase, with separate antennas).  One was positioned near a known point that had been accurately surveyed in, the other was used to mark the position of whatever work you were doing.  The idea was that the signal of each was inaccurate in the same way, so you could post-differentially correct the working GPS with the fixed base station GPS's signal.

For the study we did, we wanted to correlate the chlorophyll in the lake with satellite images of the lake that were to be taken concurrent to our sampling to see if satellite data could be used to measure lake chlorophyll and productivity.  So, we needed to coordinate:

1.  A bright clear sky day, so the satellite could see the lake and take pictures.
2.  Professional surveyors with a base station GPS and field unit to get accurate locations for the sample sites.
3.  5 teams and sample boats to quickly take a "snapshot" of chlorophyll by collecting water samples over the entire lake surface (about 35 miles of lake).  I don't remember exactly, but I think we had about 40-50 sample locations to cover in about two hours.

At each station, we'd first take a secchi measurement by lowering a black and white quadrant patterned disk into the water until it just went out of sight.  This allowed us to see how deep light penetrated into the water column.  We reasoned that the photic zone (zone where there is enough light for photosynthesis to occur) is twice that secchi depth, since the light had to travel through the water to the disk, reflect off it, and come back through the water to our eye (i.e., twice through the water column).  

We collected two samples.  One was a surface grab sample, where we simply immersed a clean sample bottle, rinsed it several times, and collected a water sample just under the surface (being careful not to get surface scum or floating debris).  The second was an integrated sample.  To collect that one, we had a 20 foot 2" pvc pipe with a one-way valve on the bottom.  We slowly immersed that pipe to the depth of the photic zone, essentially "cutting a core" out of the water that was as long as the photic zone is deep.  We took the pipe out of the water and collected the sample in a bucket, stirred it up (integrating it), and got a sample in a sample bottle. 

All the samples were placed in dark coolers and iced to slow biological processes that might change chlorophyll concentrations, and the samples were taken back to a field lab where our lab folks measured the chlorophyll using a spectrophotometer.  

These data were later merged with the position data, which was merged with the satellite image data.  At the time, cutting edge stuff.  Now of course, any cell phone gets better position data, and just about any one of our ENVS graduates can do the mechanics of the study.

Technology moves on, but at the end of the day everyone can still enjoy the sunset.

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