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The reappearance of long-forgotten habitats and the resurgence ofspecies unseen for years may not be among the expected effects of anatural disaster. Yet that's exactly what researchers have found onthe sandy beaches of south central Chile, after an 8.8-magnitudeearthquake and devastating tsunami in 2010. Their study alsorevealed a preview of the problems wrought by sea level rise - amajor symptom of climate change. In a scientific first, researchers from Universidad Austral deChile and UC Santa Barbara's Marine Science Institute (MSI) wereable to document the before-and-after ecological impacts of suchcataclysmic occurrences. A new paper appearing in the journal PLoS ONE elucidates thesurprising results of their collaborative study, pointing to thepotential effects of natural disasters on sandy beaches worldwide. "So often you think of earthquakes as causing total devastation,and adding a tsunami on top of that is a major catastrophe forcoastal ecosystems. As expected, we saw high mortality ofintertidal life on beaches and rocky shores, but the ecologicalrecovery at some of our sandy beach sites was remarkable," saidJenifer Dugan, an associate research biologist at MSI. "Dune plants are coming back in places there haven't been plants,as far as we know, for a very long time. The earthquake createdsandy beach habitat where it had been lost. This is not the initialecological response you might expect from a major earthquake andtsunami." Their findings owe a debt to serendipity. With joint support fromChile's Fondo Nacional de Desarrollo Cientifico y Tecnologico andthe U.S. National Science Foundation's Long Term EcologicalResearch program, the scientists were already knee-deep in acollaborative study of how sandy beaches in Santa Barbara and southcentral Chile respond, ecologically, to man-made armoring such asseawalls and rocky revetments. As part of that project, the Chilean team surveyed nine sandybeaches along the coasts of Maule and Biobio in late January, 2010.The earthquake hit in February. Realizing their unique opportunity, the scientists quickly changedgears and within days were back on the beaches to reassess theirstudy sites in the catastrophe's aftermath. They have returned manytimes since, diligently documenting the ecological recovery andlong-term effects of the earthquake and tsunami on thesecoastlines, in both natural and human-altered settings. The magnitude and direction of land-level change brought thegreatest impact, drowning beaches especially where the tsunamiexacerbated earthquake-induced subsidence - and widening andflattening beaches where the earthquake brought uplift. The drownedbeach areas suffered mortality of intertidal life; the widenedbeaches quickly saw the return of plants and animals that hadvanished due to the effects of coastal armoring. "With the study in California and our study here, we knew thatbuilding coastal defense structures, such as seawalls, decreasesbeach area, and that a seawall results in the decline of intertidaldiversity," said lead author Eduardo Jaramillo, of UniversidadAustral de Chile. "But after the earthquake, where significant continental upliftoccurred, the beach area that had been lost due to coastal armoringhas now been restored. And the re-colonization of the mobile beachfauna was under way just weeks after." With responses varying so widely depending on land-level changes,mobility of flora and fauna, and shore type, the findings show notonly that the interactions of extreme events with armored beachescan produce surprising ecological outcomes - but also suggest thatlandscape alteration, including armoring, can leave lastingfootprints in coastal ecosystems. "When someone builds a seawall, not only is beach habitat coveredup with the wall itself, but, over time, sand is lost in front ofthe wall until the beach eventually drowns," Dugan said. "The semi-dry and damp sand zones of the upper and mid intertidalare lost first, leaving only the wet lower beach zones. This causesthe beach to lose diversity, including birds, and to loseecological function. This is an underappreciated human impact oncoastlines around the world, and with climate change squeezingbeaches further, it's a very serious issue to consider." Jaramillo elaborated, "This is very important because sandy beachesrepresent about 80 percent of the open coastlines globally. Also,sandy beaches are very good barriers against the sea level rise weare seeing around the world. It is essential to take care of sandybeaches. They are not only important for recreation, but also forconservation." The study is said to be the first-ever quantification of earthquakeand tsunami effects on sandy beach ecosystems along a tectonicallyactive coastal zone. We are high quality suppliers, our products such as China Car Key Programer , China Vag Diagnostic Equipment for oversee buyer. To know more, please visits Car Key Programer.
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