Poland’s Amazing Coastal Dunes

By Awake! writer in Poland

PICTURES usually portray rural Poland as a deep-green landscape of well-watered farms, fields, and forests. But did you know that Poland also possesses an amazing landscape of rolling white dunes that are visible even from outer space? Confined to an 11-mile [18 km] stretch of the Baltic Coast, this patch of quasi desert is one of the most popular features of Słowiński National Park.

There, says an official reference, “sea, lakes, rivers, dunes, forests, peatbogs and meadows border on each other to form a diversified mosaic of environments. . . . Only here do dunes run straight into lakes and forests.” Indeed, the park’s complex of migrating dunes​—called the white dunes or white hills—​and shallow lakes is unique in all of Europe.

These massive mounds of white and yellow sand constitute the largest dune area in Europe​—about 1,200 acres [500 ha]—​not stabilized by vegetation. Fittingly, Słowiński National Park’s official symbol is a white gull soaring  above a yellow dune and blue water.

More common in the park, but less dramatic, are the so-called gray dunes. Older than their white counterparts, they are overgrown with grass and trees that, besides forming soil, stabilize the sand by anchoring it and shielding it from direct exposure to the elements. One gray dune even has the distinction of being the highest of all the dunes in the park. Named the Czołpino dune, it is about 180 feet [55 m] high.

When visitors see the dunes​—especially the vast expanse of migrating white dunes—​many naturally ask, “Where did all the sand come from? And why did so much of it accumulate on this relatively small section of the Baltic Coast?”

The Birth of the Dunes

Although researchers have no definite answers to the aforementioned questions, evidence points to human involvement. Scientists have deduced this by studying the pollen preserved in the various layers of soil, termed “fossil soil,” in the park. Their research has revealed that the area now occupied by dunes was once well forested, primarily with oak trees. So, what caused the radical change in the landscape?

It is believed that before our Common Era, large areas of coastal forest were destroyed by catastrophic fires resulting from the activity of the tribes inhabiting the region. “The sands, formerly stabilized by the forests, moved for the first time,” says the book Słowiński National Park. According to the pollen record, however, forest again took hold, first in the form of beech trees and later, pine trees.

But then during the Middle Ages, for some unknown reason, the dunes were stirred from their slumber and again went on the march. In the 16th century, they even threatened to engulf the old town of Łeba. The people reacted by building another town, away from the danger zone, but their efforts only  made matters worse. Says the book Słowiński National Park: “The building of the town and port was accompanied by massive felling of trees but nobody seemed aware of the consequences.” The logging, says the above reference, “resulted in movement of the dunes on a scale never seen before.” Moving at a rate of between 10 and 30 feet [3-10 m] a year, migrating sands overwhelmed villages, fields, meadows, and even forest areas.

Where Did the Sand Come From?

Humans may have played a role in the localized change in the landscape, but they did not bring in the sand. So where did it come from? And is the process continuing? The answers may indicate how the park will fare in the future.

Researchers believe that some sand may have come from inland deposits and that it was carried down to the sea by rivers. Another source may be the coastline itself, where wave action continuously erodes cliff faces​—a process called abrasion. Along one stretch of the Baltic Coast, for example, waves roll in at a 45-degree angle to the shore, slowly wearing away the cliff face and carrying away the sand. The result is an accumulation of sand on the seabed.

In ways not yet fully understood, ocean currents and waves work together to transport some of this sand from the seabed to just off the coast of the national park, where it forms large sandbars and shoals that run parallel to the shoreline. Waves and inshore currents then progressively shift sand to the beach, where sun and wind take over, drying it and blowing it inland. There it forms several parallel ridges that get progressively bigger as sand blows from one ridge to the next, ultimately forming the white dunes.

Lakes by the “Desert”

Despite the foregoing, Słowiński National Park is far from being a lifeless desert. On the contrary, it is a thriving haven of life blessed with an abundance of water. In fact, dunes and beaches make up only about 5 percent of the park’s area, while rivers, lakes, and streams cover about 55 percent.

The largest of the lakes is Lake Łebsko, which has an area of 28 square miles [71 sq km] and a maximum depth of about 20 feet [6 m]. The biggest of the rivers, the Łeba, flows into this lake. The lake second  in size is Gardno, which is fed by the Łupawa River. Because of their sandy, unstable surroundings, the shorelines of these two lakes undergo constant change.

A Haven for Plants and Wildlife

The lakes, rivers, and streams complement the park’s three major habitats​—dunes, moors, and pine forest. Together these contrasting environments support almost 900 species of vascular plants, including orchids. One of the hardiest and most ecologically valuable plants is European beach grass, also called marram grass. A pioneer plant, beach grass usually begins the process of colonizing dunes. Its scaly underground stems spread out as far as 40 feet [13 m] and send numerous shoots to the surface, forming tufts. In this way, beach grass gradually anchors and stabilizes dunes, making it possible for other plants to take root and grow.

Situated on an avian migratory route, Słowiński National Park teems with birds. Some 260 species, representing about 70 percent of all the kinds found in Poland, either make the park their home or use it as a stopover during their migration. Water birds include black-headed gulls, common terns, crested grebes, mallard, swans, and mergansers​—ducks that are easily recognized by their spiky “hairdo.” Other species include eagle owls, golden eagles, lesser spotted eagles, sea eagles, and ravens. If you have a sharp eye and walk quietly, you may also observe some of the mammals residing in the park, such as red deer and roe deer, wild boars, hare, and raccoon dogs, which are related to the fox.

A Hiker’s Paradise

Hiking is the only form of tourism allowed. To that end, the park has 85 miles [140 km] of walking trails, which can take one progressively through each of the different habitats: coniferous forests; gray dunes, meadows, moors, and marshes; lakes with their viewing platforms and watchtowers; white dunes; fore dunes; and, finally, miles of white sandy beaches.

Visitors who come in autumn or winter may even see the dunes put on their own special show as strong winds whip up plumes of sand from their crests, like the spray of an ocean wave. The dunes are then said to smoke. Sound is added to the spectacle as the millions of sand particles rub violently against one another, making the dunes hum, or sing.

As many as 800,000 people visit the park annually because of its amazing and diverse natural assets. No doubt many of the visitors like to escape the hustle and bustle of city life, seeking nature’s therapy for jangled nerves in the solitude of the forest, the restful rumble of the surf, and the lonely cry of the gull.

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Słowiński National Park

This park is situated on Poland’s central coast, between the towns of Łeba and Rowy. It is named after the Kashubian tribe of Słowińcy, a Slavic people who lived in the area until just before the end of the second world war. The park was inaugurated in 1967 and was designated a World Biosphere Reserve in 1977. It has an area of 45,985 acres [18,618 ha], of which water covers more than half. The rest is composed of forests (25 percent), beaches and dunes (5 percent), swamps and moors (8 percent), and meadows and pastures (8 percent).

[Map]

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BALTIC SEA

RUSSIA

POLAND

SŁOWIŃSKI NATIONAL PARK

GERMANY

CZECH REPUBLIC

SLOVAKIA

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The dunes are said to smoke when strong winter winds whip up plumes of sand

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Common tern

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Photo by Chukchi Imuruk, National Park Service

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Dunes in summer

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Dunes in winter

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Lake Łebsko

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Mergansers

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European beach grass

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Unique sand formations

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Roe deer