PhysOrg: For thousands of years, the marshes at the confluence of the Tigris and Euphrates rivers in modern day Iraq were an oasis of green in a dry landscape, hosting a wealth of wildlife. The culture of the Marsh Arab, or Ma'dan, people who live there is tightly interwoven with the ecosystem of the marshes. The once dense and ubiquitous common reed (Phragmites australis) served as raw material for homes, handicrafts, tools, and animal fodder for thousands of years. Distinctive mudhif communal houses, built...