quality:corruption
Natural history

The Euphrates flows through a number of distinct vegetation zones. Although millennia-long human occupation in most parts of the Euphrates basin has significantly degraded the landscape, patches of original vegetation remain. The steady drop in annual rainfall from the sources of the Euphrates toward the Persian Gulf is a strong determinant for the vegetation that can be supported. In its upper reaches the Euphrates flows through the mountains of Southeast Turkey and their southern foothills which support a xeric woodland. Plant species in the moister parts of this zone include various oaks, pistachio trees, and Rosaceae (rose/plum family). The drier parts of the xeric woodland zone supports less dense oak forest and Rosaceae. Here can also be found the wild variants of many cereals, including einkorn wheat, emmer, oat and rye.

South of this zone lies a zone of mixed woodland- steppe vegetation. Between Raqqa and the Syro–Iraqi border the Euphrates flows through a steppe landscape. This steppe is characterised by white wormwood (Artemisia herba-alba) and Amaranthaceae. Throughout history, this zone has been heavily overgrazed due to the practicing of sheep and goat pastoralism by its inhabitants. Southeast of the border between Syria and Iraq starts true desert. This zone supports either no vegetation at all or small pockets of Chenopodiaceae or Poa sinaica. Although today nothing of it survives due to human interference, research suggests that the Euphrates Valley would have supported a riverine forest. Species characteristic of this type of forest include the Oriental plane, the Euphrates poplar, the tamarisk, the ash and various wetland plants.

Among the fish species in the Tigris–Euphrates basin, the family of the Cyprinidae are the most common, with 34 species out of 52 in total. Among the Cyprinids, the mangar has good recreational fishing qualities, leading the British to nickname it the "Tigris salmon." The Euphrates softshell turtle is an endangered soft-shelled turtle that is limited to the Tigris–Euphrates river system.

The Neo-Assyrian palace reliefs from the 1st millennium BCE depict lion and bull hunts in fertile landscapes. Sixteenth to nineteenth century European travellers in the Syrian Euphrates basin reported on an abundance of animals living in the area, many of which have become rare or even extinct. Species like gazelle, onager and the now-extinct Arabian ostrich lived in the steppe bordering the Euphrates valley, while the valley itself was home to the wild boar. Carnivorous species include the wolf, the golden jackal, the red fox, the leopard and the lion. The Syrian brown bear can be found in the mountains of Southeast Turkey. The presence of Eurasian beaver has been attested in the bone assemblage of the prehistoric site of Tell Abu Hureyra in Syria, but the beaver has never been sighted in historical times.