Rezovska Longoz Forest

Rezovska Longoz Forest is a designated Natural Monument situated along the Rezovska River in Burgas Province, on the Bulgarian-Turkish border near the town of Rezovo in the southernmost part of the Bulgarian Black Sea coast. A longoz is a type of riparian gallery forest characteristic of the southeastern Balkans and the lower reaches of rivers flowing into the Black Sea and the Sea of Marmara. These dense, multi-layered forests develop on periodically flooded river terraces and are dominated by trees with liana-covered canopies giving them a jungle-like character. The Rezovska Longoz Forest is one of the finest remaining examples of this distinctive forest type in Bulgaria and forms part of the broader Strandzha Nature Park landscape.

The Rezovska Longoz Forest supports exceptional biodiversity, reflecting its unique combination of Mediterranean, continental, and Pontic ecological influences. The dense riparian forest provides habitat for otters along the river, a species that is increasingly rare in Bulgaria. The river and its banks support populations of water shrews and several amphibian species including the fire-bellied toad and Greek tortoise on drier margins. Bird life in the longoz is particularly rich, with Kingfisher, Black Stork, Night Heron, Little Egret, and various warblers nesting in or near the forest. The surrounding Strandzha landscape harbors Middle Spotted Woodpecker—near its northeastern range limit—as well as numerous raptors. Wild boar and roe deer are common in the forest, and the area forms part of the range of European jackal.

The longoz forest of the Rezovska River valley represents one of the most distinctive and floristically rich forest communities in Bulgaria. The forest canopy is dominated by Oriental plane (Platanus orientalis), pedunculate oak, and white poplar, with branches heavily laden with lianas including wild grape, black bryony, common ivy, traveller's joy, and white bryony. This liana-draped canopy gives the forest its characteristic impenetrable, subtropical appearance that is unique in northern Bulgaria. The ground layer in periodically flooded sections supports moisture-tolerant species, while drier margins harbor more diverse herb communities. The Strandzha region is botanically exceptional, with numerous species found nowhere else in Bulgaria, including Pontic azalea and various relict tertiary plant species.

The Rezovska River valley is carved into the soft Eocene sedimentary rocks—primarily sandstones, clays, and marls—characteristic of the Strandzha geological zone in southeastern Bulgaria and adjacent Turkey. The longoz forest develops on the river's alluvial deposits, which overlie the bedrock at a shallow depth. Periodic flooding replenishes the nutrient-rich silts that support the lush forest growth. The river itself marks the international border between Bulgaria and Turkey in its lower reaches. The Strandzha region escaped significant glaciation during the Pleistocene, and the relatively stable Quaternary climate allowed the survival of thermophilous and relict forest elements that disappeared from much of Europe during colder periods.

The Rezovska Longoz Forest area experiences a transitional climate between the continental and Mediterranean regimes, strongly influenced by the proximity of the Black Sea and the warm, humid air masses from the Mediterranean that penetrate the Strandzha region. Winters are mild, with January temperatures averaging 4–6°C and snowfall relatively infrequent. Summers are warm and humid, with July temperatures around 23–26°C. Annual rainfall is approximately 700–800 mm, distributed fairly evenly through the year. The Strandzha region receives higher precipitation than most of the Bulgarian Black Sea coast, supporting the dense forest vegetation. Autumn fog is common in the river valleys. The mild, humid climate has allowed the survival of thermophilous relict plant species that require conditions warmer than most of Bulgaria can provide.

The Strandzha region, including the Rezovska River valley, has been inhabited since ancient Thracian times. The Thracian tribe of the Asti lived in this region, and archaeological evidence of their settlements has been found throughout the Strandzha. The Byzantine period saw the establishment of monasteries in the region, and the medieval Bulgarian kingdoms controlled the Strandzha at various times. The forest's position on the border with the Ottoman Empire (later Turkey) meant that the area experienced significant population movements and was never densely settled. During the Bulgarian National Revival period, the Strandzha forests provided refuge for Bulgarian revolutionary movements. The area became a militarized border zone during the socialist period, which paradoxically helped preserve its natural landscape.

The Rezovska Longoz Forest was designated as a Natural Monument to protect one of Bulgaria's finest examples of this rare riparian forest type. It falls within the boundaries of Strandzha Nature Park, which was established in 1995 and is the largest Nature Park in Bulgaria, covering approximately 1,161 square kilometers. The strict border control that isolated the Strandzha region during the Cold War era left a legacy of well-preserved natural habitats across much of the park. The longoz forests of the Rezovska and Veleka rivers are among the most internationally recognized features of the park. The site is included in the Natura 2000 network under both the Birds and Habitats Directives.

The Rezovska Longoz Forest can be explored on foot along the Rezovska River valley, with trails leading through the dense riparian woodland. The forest's liana-draped canopy is a major attraction for visitors interested in botanical diversity and landscape photography. The river itself can be observed from its banks, with opportunities to spot kingfishers, herons, and other riparian wildlife. The nearby village of Rezovo, on the Bulgarian-Turkish border, offers views over the river mouth and the Black Sea coast. The broader Strandzha Nature Park offers extensive trail networks connecting the longoz forests with other key habitats including oak-hornbeam forests, meadows, and the Veleka River estuary.

Access to the Rezovska Longoz Forest requires travel to the southernmost section of the Bulgarian Black Sea coast, passing through Ahtopol and continuing toward Rezovo. The road to Rezovo passes through Strandzha Nature Park and is generally accessible to ordinary vehicles. The village of Rezovo is small and has very limited facilities. Basic accommodation and services are available in Ahtopol, approximately 10 kilometers to the north, or in Tsarevo, the main town of the southern Bulgarian Black Sea coast. The Nature Park visitor center in Malko Tarnovo provides information on the park's features and trails. Visitors from Burgas can reach the area in approximately 2 hours by car.

The Rezovska Longoz Forest faces conservation challenges including the management of riparian hydrology to maintain periodic flooding that is essential for longoz forest renewal, control of invasive plant species that could displace native components of the forest, and management of human disturbance from increasing visitor numbers. The border location of the forest, while historically a protection against development, now presents management challenges as the border becomes more permeable. Climate change poses a significant long-term threat, as altered rainfall patterns and increased drought frequency could affect the flooding regime essential for longoz forest maintenance and could allow the northward spread of more drought-tolerant plant species at the expense of the relict Pontic forest elements.