Seas rise, trees die: Cli­mate change be­fore your very eyes

The Washington Times Daily - - NATION - BY WAYNE PARRY

PORT REPUB­LIC, N.J. | They’re called “ghost forests” — dead trees along vast swaths of coast­line in­vaded by ris­ing seas, some­thing sci­en­tists call one of the most vis­i­ble mark­ers of cli­mate change.

The process has oc­curred nat­u­rally for thou­sands of years, but it has ac­cel­er­ated in re­cent decades as po­lar ice melts and raises sea lev­els, sci­en­tists say, push­ing salt wa­ter farther in­land and killing trees in what used to be thriv­ing fresh­wa­ter plains.

Ef­forts are un­der­way world­wide to de­ter­mine ex­actly how quickly the cre­ation of ghost forests is in­creas­ing. But sci­en­tists agree the star­tling sight of dead trees in once-healthy ar­eas is an easy-tograsp ex­am­ple of the con­se­quences of cli­mate change.

“I think ghost forests are the most ob­vi­ous in­di­ca­tor of cli­mate change any­where on the Eastern coast of the U.S.,” said Matthew Kir­wan, a pro­fes­sor at Vir­ginia In­sti­tute of Marine Science who is study­ing ghost forests in his state and Mary­land. “It was dry, us­able land 50 years ago; now it’s marshes with dead stumps and dead trees.”

It is hap­pen­ing around the world, but re­searchers say new ghost forests are par­tic­u­larly ap­par­ent in North Amer­ica, with hun­dreds of thou­sands of acres of salt-killed trees stretch­ing from Canada down the East Coast, around Florida and over to Texas.

The in­trud­ing salt wa­ter changes coastal ecosys­tems, cre­at­ing marshes where forests used to be. This has nu­mer­ous ef­fects on the en­vi­ron­ment, though many sci­en­tists cau­tion against view­ing them in terms of “good” or “bad.” What ben­e­fits one species or ecosys­tem might harm an­other one, they say.

For in­stance, mi­gra­tory birds that rely on coastal forests have less habi­tat. And the death of the trees makes soil mi­crobes re­lease ni­tro­gen, which adds to ni­tro­gen al­ready oc­cur­ring from other sources, in­clud­ing agri­cul­tural runoff, to con­trib­ute to al­gae blooms and re­duced oxy­gen that can sicken or kill fish.

But the con­ver­sion of for­est into marsh­land pro­duces “ex­tremely pro­duc­tive” wet­lands that feed and shel­ter fish and shell­fish.

The At­lantic croaker fish, for in­stance, was rare 15 years ago in south­ern New Jersey waters but now is abun­dant, said Ken Able, a Rut­gers Univer­sity pro­fes­sor.

“There is a lot of change go­ing on,” said Greg Noe, a re­search ecol­o­gist with the U.S. Ge­o­log­i­cal Sur­vey. “It’s dra­matic and it’s chang­ing faster than it has be­fore in hu­man his­tory.”

Quan­ti­fy­ing the rate of in­crease in ghost forests is a ma­jor fo­cus of Mr. Able’s re­search. Some sci­en­tists say the in­crease be­gan around the time of the In­dus­trial Rev­o­lu­tion, while oth­ers say the speedup be­gan more re­cently than that.

In the past 100 years, Mr. Kir­wan said, 100,000 acres of for­est in the Ch­e­sa­peake Bay has con­verted to marsh­land. Photographs show the rate of coastal for­est loss is four times greater now than it was dur­ing the 1930s, he said.

Seas off the East Coast have risen by 1.3 feet over the last 100 years, said Ben Hor­ton, a Rut­gers Univer­sity pro­fes­sor and ex­pert on sea level rise. That is a faster pace than for the past 2,000 years com­bined, he said.

Some of the most dra­matic anec­do­tal ev­i­dence of the ac­cel­er­a­tion in ghost for­est cre­ation is along the Sa­van­nah River be­tween Ge­or­gia and South Carolina, Mr. Noe said.

When his team first got there 10 years ago, “it looked like the trees were un­der a lit­tle stress, but they were all alive,” he said. “But five years later, the vast ma­jor­ity of them were dead. That hap­pened right in front of our eyes, much faster than we ex­pected.”

ASSOCIATED PRESS

Ris­ing sea lev­els are killing trees along vast swaths of the North Amer­i­can coast by in­un­dat­ing them in salt wa­ter. Re­searchers call these dead trees “ghost forests.”

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