New island, same old ecological succession theory

Norderoogsand / Illustration by Perry Shirley

By John Upton

It’s easy to think of the earth’s lands as static. But shorelines are constantly shifting as sea levels and land masses rise and fall. New islands can appear, and old ones can be engulfed by the tides.

Sandbanks appear frequently in the  Wadden Sea National Park, off the coast of Germany, as tides and waves push particles of sand around. These are normally ephemeral features that wax and wane like an erratic moon.

But during the past decade, scientists have watched with interest as one particular sandbank has weathered the storms and grown into a full blown island.

Norderoogsand, as it is named, is sheltered by nearby islands and has benefited from rare occurrences of high storm surges during its short life. As reported by The Telegraph, some of the dunes on  the 34 acre island have reached four meters.

Norderoogsand is already home to grasses and seabirds. These are among the wildlife that typically first occupy a new island. According to ecological succession theory, pioneer species such as these are the first to colonize a new or recently scorched land mass. Pioneer species travel easily and they are generally hardy.

Once pioneer species have been established, the environment becomes more accommodating for other species, such as mammals and slow-growing trees.

“Birds are usually first to arrive naturally, and they can often bring in plant seeds or other species in their feathers or droppings,” Dan Grout, a scientist at the nonprofit Island Conservation, told me. “The rate of colonization will depend on the few usual factors such as distances to other land masses, likely migration routes and, not insignificantly, whether human visitation will assist in any directed or inadvertent release of organisms.”

Scientists are looking forward to watching as ecological succession plays itself out on the young island, where gulls, geese, plovers, terns and peregrine falcons have been spotted. “It is to be hoped that the rare sandwich tern will also discover these dunes as a breeding place,” a conservationist told Die Welt newspaper.

But the ecological extravaganza could be fleeting, the experts warn. The entire island could yet be wiped out by a strong tide surge.