拉丁美洲海岸侵蚀的现状英文文献和中文翻译(2)
In addition, tectonic subsidence is often a cause of regional vulnerability, as well as that which occurs in areas of permanent loss of sediments, owing to deforestation or to fragmentation of coastal ecosystems (e.g., sand dune vegetation, mangroves), to land use changes (mostly for agriculture and cattle ranching, and focal urban sprawl) and to sediment deficits caused by the presence of infrastructure (dams in the watersheds, jetties and groynes). Regionally, differentiated climatologic and oceanographic forcing mechanisms impose different responses to the varied geologic-geomorphologic environments. In this article we analyse coastal erosion in Latin America and the challenges it presents to the region. We first highlight the relevance of Latin America in terms of its biopersity and show the spatial patterns of species richness; we then analyse the population at risk throughout the low lying coastal areas, as well as the demographic trends and economic growth. To assess the vulnerability of this region we also analyse the vulnerability and resilience of key coastal ecosystems, and explore the most frequent and intense hazards that occur in the coastal zones, namely tropical cyclones, sea level rise, ocean acidification, earthquakes and tsunamis. Finally, we discuss some case studies of coastal erosion across Latin America; in Cuba, Puerto Rico, Mexico, Costa Rica, Brazil, Uruguay and Chile. We close the study by pinpointing the main areas of concern in Latin America and explore possible strategies to be considered in order to sustain economic growth, minimize population risk and maintain regional biopersity. LATIN AMERICA IN A WORLD CONTEXT Different criteria exist to define the countries that make up Latin America, but for the purposes of this study, we focused on those countries where Spanish, Portuguese or French is spoken and which are considered as Latin American by the World Bank (2014). Hence, Latin America consists of twenty countries (see Figure 1). Of these, only Bolivia and Paraguay have no coastline, while three countries are islands (Cuba, Dominican Republic and Haiti). Based on economic criteria, the World Bank has considered Haiti as a low-income country; Bolivia, El Salvador, Guatemala, Honduras, Nicaragua and Paraguay are lower middle income countries and the rest (Argentina, Brazil, Chile, Colombia, Costa Rica, Dominica, Dominican Republic,
Ecuador, Mexico, Panama, Peru, Uruguay, and Venezuela) are upper middle income countries. Figure 1. Location of the countries of Latin American. Biopersity As reported by Mittermeier et al., (1997), 70% of the world´s biopersity is concentrated in some 17 countries, which are described as "megaperse" by the World Conservation Monitoring Centre of the UN Environment Programme (UNEP-WCMC). Of the ten most megaperse nations in the world, six are Latin American: Brazil, Colombia, Peru, Mexico, Ecuador and Venezuela (1st, 2nd, 4th, 5th, 6th and 9th, respectively). The potential loss of ecosystems due to sea level rise and coastal erosion will have a shift in response patterns of biopersity, both terrestrial and marine. Spatial patterns of coastal and marine persity vary throughout Latin America. Coral reefs (Figure 2a) occur mostly along the Atlantic coast, and are concentrated in the Caribbean, Mexico, Central America, Colombia, Venezuela and some parts of the central region of the Brazilian coast (IMaRS-USF, 2005; IMaRS-USF and IRD, 2005; Spalding et al., 2001; UNEP-WCMC et al., 2010). Worldwide, there is greatest coral reef species richness in South East Asia, while the Caribbean-Central America and India follow (Tittensor et al., 2010a). Mangroves are more widely distributed than coral reefs, and are found along the Pacific and Atlantic coasts of Latin America (Figure 2b), on both shorelines of Mexico, the Caribbean, Central America, Colombia, Venezuela, Ecuador and Brazil (Spalding et al., 2010a; 2010b; Lopez-Portillo et al., 2011). As with the spatial pattern of coral reefs, the highest species persity of mangroves is also found in South East Asia (Tittensor et al., 2010a), but ranking in second place are central America, Colombia and Venezuela. Seagrasses follow a similar distribution pattern, except that they are more scarce on the Pacific coast, do not occur in Ecuador, but are found in Chile (Green and Short, 2003) (Figure 2c). Seagrass biopersity is also concentrated in South East Asia, while the second most perse area is the eastern coast of Africa, followed by the Caribbean (Tittensor et al., 2010a; 2010b). Finally, Tittensor et al., (2010a; 2010b) analysed the global patterns of marine persity in terms of species richness, and considered a total of 11,567 species that covered 13 major coastal and maritime species groups: marine zooplankton, mangroves, seagrasses, corals, squids, cephalopods, fish (coastal fish, tuna and sharks) and mammals (cetaceans and pinnipeds). In Latin America, marine biopersity is greatest in the Caribbean,