Vernal Pools and Islands of Vegetation

I already described how Vernal Pools support Fairy Shrimp on Enchanted Rock.  Another result of the Vernal Pools are islands of vegetation that form up on the bare rock.

Vernal Pools are shallow depressions that temporarily hold water after rain. Algae grows in the water, and organic matter also get trapped.  In addition, blowing sand and stone fragments are also trapped in these pools. In the image below a Vernal Pool is drying out.  You can see the algae and other material left on the bottom.

Drying Vernal Pool

Over many years enough sediment and organic matter might collect in a pool to support plant life.  Grass seed blowing across the rock will find its way into the pool and sprout. In the middle pool below you can see grass sprouting on the left side of the pool.

Vernal Pool with Vegetation

Once grass starts to grow the depression catches even more sediment and organic matter, and larger plants gain a toehold.  Cactus and Yucca seem to be the next plants to sprout.

Prickly Pear and Grass

Yucca and Grass filling Vernal Pool

With enough time the soil and vegetation will deepen, and may eventually support small trees. Unfortunately the tree in the image below seems to have succumbed to the drought. 

Vernal Pool with (dead) Tree

Who knew that these shallow depressions in rock could eventually support an entire plant community?

Mark

Vernal Pools and Fairy Shrimp

One of the interesting micro ecosystems here at Enchanted Rock are the Vernal Pools up the rock itself. A Vernal Pool is a shallow depression that fills with water after rain.  Most of the pools will only hold water for a few days, but the deeper ones will stay full for several weeks.

Vernal Pool on Enchanted Rock

The deepest Vernal Pools host a tiny crustacean known as Fairy Shrimp. They are similar to Brine Shrimp or "Sea Monkeys" that we might have seen as children. The Fairy Shrimp have a very short life cycle, and their eggs persist in dried out pools for months. The eggs lay in the bottom of dried out Vernal Pools until it rains, at which time they hatch. The shrimp grow quickly and reproduce, laying eggs before the pools dry up. Fairy Shrimp are slow-moving and tasty, and they can't successfully exist in water with fish or other predators. Hence their need for short-lived Vernal Pools.

Vernal Pool with Fairy Shrimp

The Fairy Shrimp can blend into the bottom of the pools. Can you find the three Fairy Shrimp in the photo below?  They look like tiny gray tadpoles.

Fairy Shrimp

Here they are circled.

Fairy Shrimp - circled

Check back for another blog that will discuss life at the Vernal Pools.

Mark

Finished Our First Assignment

We've been here at Enchanted Rock for 4 weeks.  It has taken a while to get going on projects.  We only have to work 24 hours a week for the site.  That means we both work 2 days a week, 6 hours each of those days. 

Our first couple of weeks we spent our time checking cars for parking permits, cleaning the bath houses, and checking campsites for permits.  That left the remaining five hours to pick up trash.  We finally convinced the staff that we were willing and able to do much more to help out.  

Finally, we got our first project - painting 21 deer blinds and making repairs to any that needed it. We hopped right on that project.  The hunt here in the park is the first week in December so we were under a deadline to finish.

While painting, we found two wasps nests, one mouse nest with several hairless babies, and one bull snake.

Most of the blinds were in pretty good shape but there were a few repairs to be made:

Even though we ran out of paint twice (and had to create custom blends by scavenging partial cans of leftover paint), we completed our tasks this past week. 

On to the next project!

Teri

Hole - In - One !

After just a little over a year of playing disc golf, Mark got his first hole-in-one today!
Can you see the basket?  It couldn't be seen from the tee:

It is really tucked into the middle of two giant pecan trees:

The disk is laying on the left side of the basket:

It's customary to write your name and date on the rim of the basket after a hole-in-one:

Mark wrote his name in pencil so that it would eventually wash away. 

He will always remember his first ace!

Veterans Day

Those we love don’t go away

They walk beside us every day

Unseen, unheard, but always there

Still loved, still missed

Still very dear.

Enchanted Butterflies

Teri and I took a hike around Enchanted Rock this morning, and were surprised by the number and variety of butterflies that we saw.  There are not many flowers blooming, but those that are seem very popular.

Dainty Sulphurs and Common Mestras are everywhere.  We saw hundreds of them moving about.

Common Mestra

Dainty Sulphur

Some of the large flowers were attracting more than one species of butterfly.

Black Swallowtail and Queen

Queen and Monarch

We saw singles of a few species.

Common Buckeye

Common Checkered-Skipper

Variegated Fritillary

Vesta Crescent

We are expecting our first freeze next week, so the number of butterflies will decrease soon.  We will enjoy them while we can!

Mark

Geocaching Hawaii

This past summer, while in Colorado, we picked up a couple of Geocache Trackables.  A trackable is assigned a unique tracking ID which allows them to travel from geocache to geocache.

We hauled them to Hawaii and have been having fun following them as they are moved from site to site.

We left this one on the Big Island:

And this one was left at the salt flats on Kauai:

We haven’t been geocaching for very long, but we already have found 84 caches in 5 different states.  It’s a fun way to get out and see the area.

Teri