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March 8, 2019. Life / Islands

Wallacea

Nicholas D. Holmes, Olivier Langrand, Russell A. Mittermeier, Anthony B. Rylands, Thomas Brooks, Dena R. Spatz, James C. Russell, Wes Sechrest, Federico Mendez Sanchez

The Wallace and Lydekker Lines frame the islands of the Wallacea Biodiversity Hotspot. Wallacea is made up of thousands of islands which cover 338, 800 km2 in total —comparable in size to the Philippines— and are grouped in three biogeographic regions: Sulawesi, Maluku, and the Lesser Sundas. Wallacea is named after the great British naturalist and explorer Alfred Russel Wallace.

Sulawesi, together with the Sangihe-Talaud Archipelago and the Togian, Banggai, and Sula island groups, has the largest land area (186,000 km2).

Maluku (70,000 km2) is composed of the islands of Halmahera, Bacan, Obi, Seram, Buru, Tanimbar, Banda, and Kai.

Five main islands make up the Lesser Sundas (81,000 km2): Lombok, Sumbawa, Sumba, Flores, and Timor.

Wallacea’s complex geological history created young oceanic islands ringed by limestone (e.g., Lombok and Flores), continental crustal fragments (e.g., Sumba and Timor), and composite islands whereby different islands joined due to tectonic action (e.g., Sulawesi and Halmahera).

 

This is an excerpt from the CEMEX Nature Series Book “Islands” (2018)

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