The Acarlar Floodplain Forest in Sakarya, Türkiye’s largest single-piece floodplain forest, provides a unique habitat for plants and animals adapted to changing water levels, thanks to its distinctive ecosystem and rich biodiversity.
Located between the northern districts of Karasu and Kaynarca, the forest is home to 654 plant species from 360 genera across 97 families. Six plant species, including the endangered lake onion and the water violet found only in this area in Türkiye, are protected under the Bern Convention.
Registered as a Wildlife Development Area in 2004, the floodplain forest also stands out with 14 endemic plant species, including kilyos button, Istanbul snowdrop, wild sorrel, Anatolian mullein and Black Sea wisteria, underscoring its botanical diversity.
Covering an area of 24 square kilometers shaped by water dynamics, Acarlar Floodplain Forest provides habitat for 235 resident and migratory bird species, 147 of which are protected under the Bern Convention. These include herons, spoonbills, cormorants, diving birds, ducks, pheasants, woodcocks and sea and fish eagles.
The area, where rare and sensitive species coexist, also hosts fish such as eel, carp, catfish, pike and mullet, as well as various mites and algae that thrive despite fluctuating water levels.
Declared a first-degree natural protected site in 1998, the forest allows visitors to observe plant and bird species and explore its natural beauty via 1,250 meters of renovated wooden walkways and bridges. Drawing growing interest for combining marine, lake, dune and forest ecosystems, Acarlar Floodplain Forest welcomed around 350,000 visitors last year.
Associate Professor Mehmet Sagiroglu of Sakarya University’s Department of Biology said Acarlar is one of Türkiye’s three major floodplain forests, along with Igneada and Karacabey. He explained that such forests form when seasonal rains raise water levels, flooding surrounding lands, and noted that while Acarlar has no direct connection to the Black Sea, excess water is drained to the Sakarya River.
Emphasizing the area’s high biodiversity, Sagiroglu said the forest hosts a wide range of life forms, from birds and mammals to invertebrates and plants, adding that he has conducted field studies there with students to accurately document plant diversity.
Sagiroglu also pointed to waste problems caused by heavy visitor traffic, but said the benefits of public awareness outweigh the negatives. He noted that local communities use many plant species found in the forest, particularly the economically valuable lake onion, which is harvested with official permission in spring. According to studies, local residents use around 100 plant species from the area.
Stressing the importance of sustainable use, Sagiroglu said such areas should be carefully managed through protection and public education, adding that floodplain forests like Acarlar should be valued not only for conservation but also for their economic and cultural contributions.
