Monday, April 13, 2009

Scrub a Dub Dub, a Day at Yamato Scrub

Yamato Scrub
Boca Raton, Florida

Visiting the Florida Scrub habitat is like visiting the southwest desert - so alien to the rest of Florida's habitats. It is arid, sandy, thorny, and hot.
Because of the heat and sun exposure, the animals mostly live underground and come out at night, the plants and animals are adapted to fire - which often sweeps through after a lightning storm, and many of the animals and plants that live there - live ONLY there - endemic to that little island of sand.

Florida's Scrub habitats are ancient sand dunes - sculpted by the blowing of the wind and the movements of the ocean. Over and over again in history, Florida has been under water, partially under water, or mostly exposed. When ice ages come-on and the planet's water freezes, Florida's land mass becomes exposed and the peninsula becomes large and dry. When the glaciers melt, the oceans fill and Florida's low lands become part of the ocean once again.

Scrub lands are some of the most ancient habitats in Florida because they are the areas of land that would have most likely remained dry when the rest of Florida was under water - and therefore, have been establishing themselves for long, consistent periods of time.

They might have been islands, or sand bars, or the coastline of a much smaller Florida. If you look at a topical map of Florida, you can see those ridges that may have once been islands- along the coasts, and right down the middle of Florida. The ridge traveling down the middle of the peninsula is known as the Lake Wales Ridge, - an ancient and fascinating place.

Yamato Scrub, in Boca Raton, Florida, is part of the Atlantic Coastal Ridge. At one time it was part of the beach line for the eastern shore of Florida.

Over millions of years sediment, from the mountains in Georgia and the Carolinas, has drifted and flowed south into Florida. The sediment is pushed back and forth, up and down- moving along the coast - creating dunes and barrier islands, flowing through rivers and streams - building up and flooding down - always on the move. At one time, the area north of Yamato Scrub, where the Loxahatchee National Wildlife Refuge now sits, there was an estuary of a great river. This estuary pushed up sand on it's northern and southern sides, creating a ridge of high, sandy ground - which is now called the Yamato Scrub.

Historically, these scrub areas have often been isolated - sometimes as true islands, surrounded by water, other times their seclusion due only to their higher elevation and sandy soils. The animals and plants that survived, and therefore, evolved and adapted, became endemic to those islands, meaning they live in the scrub, and only in the scrub. An example would be the Florida Scrub Jay, It is related to the common Blue Jay and the Western Scrub Jay, but completely adapted to thousands of years living in the Florida scrub. They are birds that will captivate your interest and make you want to learn more. They are endangered, very endangered - due to the fact that we are eliminating our scrub lands - building strip mall after strip mall on their dry and high ground!

Not only are these scrub lands beautiful and a sacred haven for unique and unusual animals, but they are important to our water supply!
How, you ask? Well, when it rains on these sandy soils, the rain filters through the sand and cleans itself as it delves deeper, once it trickles into the aquifer, it is clean.

There is so much to say about Florida Scrub: like how the ecosystem relies on fire to sustain itself, and how some of the plants have very long tap roots to find water, or like how some of the trees, like the scrub oak, may look like small trees above ground, but are hiding their true bulk under the sand for fire protection, and how fire helps burst the sand pine's cones...a truly phenomenal place, but I don't want to tell you everything, go out and discover for yourself.

I wanted the kids to understand the ecosystem, not just visit it, so I planned some experiments - based on lessons prepared by the teachers at the Archbold Station website (see the link above). The first activity was an experiment to test how burrows in the sand might hold up to pressure.
The burrows held up very well. Many of the animals in the scrub are burrowing animals. They stay underground during the hot day and come out at night to eat and hunt. A great example is the Gopher Tortoise (whom we have talked about in detail in earlier blog posts). Gopher Tortoises create huge, complex burrows - sometimes 40 feet wide and 10 or more feet deep. These burrows become homes to many different animals, like the Gopher Frog, the Indigo Snake, among many more. During a fire, the burrow is safe - below ground, away from the heat. During cold, it is warm, and during intense heat - it is cool and shady.

We learned how changeable dry sand can be - flowing like a liquid and moving and shifting, or as a solid wall when faced with shock. Burrows - the shallow, long ones, work due to this shape-shifting trait.

On our walk we discovered and appreciated so many things. The place itself is beautiful - well taken care of and maintained with neat and accessible trails, but also allowing for the more wild side with sandy trails through the Palmetto, and pine-needle covered trails through the Pine Flatwoods.

We measured and examined Saw and Scrub Palmettos, both relatives to our friend, the Cabbage Palm or Sabal Palmetto.

The Saw Palmetto is the prickly cousin of the palms, named for its saw like branches - so easy to recognize.

The Scrub Palmetto looks more like the Cabbage Palm, but has more, what I call, Hair. It has wispy "hairs" coming off its leaves. We found out that you can measure the age of the Saw Palmettos by measuring how many inches there are from where the leaves start to where the stem sticks out of the sand, and then dividing that by 1.2. A biologist found out that they grow at a rate of 1.2 inches a year, hence the dividing factor. We discovered that most of the trees were about 40-5o years old. In Lake Wales Ridge, some are as old as 700 or more years!!! That's an old tree!

We enjoyed the blooming Prickly Pear along the way,

and seeing extraordinary things like Reindeer Moss Lichen.

On our way down the sandy side trail, a mom with really keen eyes spotted a very young Gopher Tortoise hatchling.
What a sight! It was so cute and so camouflaged, and very hard to see. The kids sat and watched as he or she tried to decide what to do - flee or stand still. Eventually the little tortoise decided to hide under a leaf - a game of hide-n-seek. I'm not sure how young the tortoise was - my guess is a few weeks, maybe even less, but I think they grow slowly.
I looked online and couldn't find any more information on it - if anyone knows, please leave a comment for me.

Since we are a wild bunch, we decided to take the nature/woodsy trail. The trail runs through the pine flatwoods and is wonderfully shady and smells of pine. We examined the leaves of the oaks and looked for the bugs and/or larvae that was munching on them, we found wasp galls and talked about the teeny-tiny wasps that live inside, and we looked for the beetles that live on Saw Palmetto leaves. As we walked, I heard the tell-tale call of the Osprey.

When we turned a bend we saw a huge nest in a snag not too far away. Upon further examination we noticed the baby Osprey in the nest. We got up as close as possible, and using our binoculars, observed the nest. I knew it was a baby right away, it was big, but the downy feathers - all fluffed up around his face, were a sure sign of its youth. Osprey can live up to 35 years!! The babies lose their downy feathers after around 60 days and try to fly. They lose their juvenile spots around 18months and are considered mature at age 4-5 years. When in the nest, they are fed by the fish that the father catches. They mate for life and often return to the same nest year after year. They summer alone. The baby we saw wasn't a fledgling yet - still waiting to be big enough to fly.
We stood still and watched the bird for some time, as we walked away, the mother bird shot out of the nest, we hadn't even seen her in there. It was an exciting and memorable experience.

As we walked toward the wetland we spotted a huge bug along the trail. It was a leaf-footed bug - brown and leafy looking. Leaf-footed bugs are "True" bugs, in the order of Hemiptera. True bugs have wings that can be folded out of the way on their backs, the mouth parts are adapted for sucking and piercing, and they have stink glands. I thought I had gotten a picture of the bug close up, but don't seem to have it. The kids had fun catching it and observing it for awhile before releasing it.

We had two fabulous days out there - one very hot (around 92 F) and the other cool and pleasant (around 75 F) - what a difference! The kids enjoyed it equally - all were astounded by the wildlife and the burgeoning of new life in this wild and exemplary place.

1 comment:

  1. Very informative post. That sugar sand will keep your tires turning ... and I mean in your mind. Lots to see.


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