Sunday, May 29, 2011

Nature of a Dune

With each morning’s ramble down the beach, views to the left and right are forever a lesson, a shifting example of the divergent worlds of land and water. For the first half hour the ocean pounds on my left, while on the landward side eddies of wind stir the sand, at times rustling sea oats and beach grass on the dunes. Turning back toward home the contrasting sides shift and both land and the ocean opposite are affected by a different angle of the sun. The change in perspective is immediately noticeable in light and shadow, particularly toward the dunes. For the past months my main focus has been on the ocean with its shifting currents of blue, blue-gray, green and blue-green, on the cresting surf and the wet sand with its scatter of shells and birds. A return of the sea turtles has turned my eye toward the dunes.


Dunes are the result of wind blowing across plants on the beach. Sand particles are carried on the wind and as the wind passes across plants the windspeed slows and sand grains fall to the ground. At most times wind is a constant on the beach and little by little the windblown sand piles up and a dune grows. A variety of grasses and wild flowers colonize the dune as it grows taller. Dunes create a protected environment on their landward side allowing for various kinds of plants, which in turn support birds and animals. At different times the appearance of beach mice, doves and tortoises is not surprising. The lowest dunes provide a habitat for sea turtle eggs, sand crabs and other marine creatures. They also provide a barrier to salt intrusion from high tides and storm surges, in addition to protecting the land behind from erosion. Without the sea oats and other plant life dunes would have no anchor and blow away, changing the ecosystem drastically.


The turtle nesting season along Florida coasts is from mid-May until late October, a period of months when early morning patrols by marine biologists pinpoint the spots where large sea turtles have left egg deposits. Barriers are erected around the nesting sites, with the laying and approximate hatching dates marked on the barrier posts. The sites are monitored daily until the eggs hatch and the baby turtles make their dash to the water.


The past week four turtles have made their way to the stretch of beach along my walking path. Though it is my second time to be here for the season, there was still some excitement a few days back when I came upon a newly laid nest and the barricade put up by the biologists.


At a nesting site a mile south I got a good look at the surrounding dunes and was taken by the burst of spring growth in and around the dunes. Along with the biological renewal seen in the laying of turtle eggs, there is also a visible regeneration, a regrowth of plants and wildflowers. Interspersed with the brownish green of sea oats is a burst of red, yellow and orange from a bloom of dune sunflowers, firewheel and most surprising a fat pumpkin. In the midst of all this color I looked back over a shoulder to see the flat swath of blue water, the morning sunlight a scattering of jewels on its surface.


Something perfect about the scene a short distance above the turtle nest. Sun-worn stairs down to the beach crowded by sea oats, the white chair off to the side of a spreading firewheel plant.


A happy Halloween growing amidst the dried branches of palmetto and beach grass. Most curious of all is the Spanish moss to the left of the pumpkin’s vine and leaves. More common to the southern live oak, where it droops from branches, this plant (Angiosperm) is not common in sand dunes.


A spread of dune sunflowers, a sprinkle of firewheel in back, this is good example of the anchor plants provide to halt erosion and protect the land behind.


Couldn’t resist the splendor of this beach bouquet—a beautiful spray of firewheel flowers.


Each turtle nest is marked with this sign warning the curious to keep outside the set up barriers, to in no way interfere with the natural hatching of these endangered creatures.


For more detail on the laying of turtle eggs and their hatching, look back at Dreaming of the Sargasso Sea.

2 comments:

  1. I love that the turtles are back. It's so amazing to me that, even with all the tourists and foot traffic,so many turtles survive. The dune plants are beautiful this year - and the pumpkins! I'm going up to check them out today! As for the Spanish moss, I picture it being blown out to see on a storm, traveling hundreds or thousands of miles to NSB, washing up on shore, being dried and blown by the wind, and ending on the dune. Or, someone from Southern Oaks brought it over from DeLand and is using it for mulch on the pumpkin plants. Who knows???

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  2. I would imagine a lot of inland folks picture beach environs only as blue-green water rolling up on a white beach and never much thought of the abundance of life--both plant and animal--that abounds in both. The adaptability of the dune plants is particularly interesting and that burst of color along stretches of white sand is breath-taking.

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