Seemingly nondescript messes of tangled branches and exposed roots, mangrove forests cling to the coasts of many tropical countries. However, mangroves are far from unexceptional, providing critical ecosystem services like erosion control, flood mitigation and nurseries for fish. Mangroves also store a lot of carbon, with a hectare of mangrove forest sequestering up to four times as much carbon as a similarly sized tract of rainforest. (Source: Mongabay)