Read the following text and make a flow-chart showing the factors causing the disappearance of the mangrove forest. (One is done for you.):— A vast mangrove forest shared by Bangladesh and India that is home to possibly 500 Bengal tigers is being rapidly destroyed by erosion, rising sea levels and storm surges, according to a major study by researchers at the Zoological Society of London (ZSL) and others. Natalie Pettorelli, one of the report's authors, said, "Coastline retreat is evident everywhere. A continuing rate of retreat would see these parts of the mangrove disappear within 50 years. On the Indian side of the Sundarbans, the island which extends most into the Bay of Bengal has receded by an average of 150 metres a year, with a maximum of just over 200 metres this would see the disappearance of the island in about 20 years." The Sundarbans is known for vanishing islands but the scientists said the current retreat of the mangrove forests on the southern coastline is not normal. "The causes for increasing coastline retreat, other than anthropogenic ones, include increased frequency of storm surges and other extreme natural events, rises in seal-level and increased salinity which increases the vulnerability of mangroves," said Pettorelli. 1. Frequent storm surges → 2 → 3 → 4 → 5 → 6.