Old-growth Forests in Bulgaria: Distribution, Characteristics and Conservation Issues

d Pinus heldreichii forests in the Pirin Mountains, Picea abies forests in Rila and Rhodopes Mts., Pinus nigra in the Rhodopes and beech-fir-spruce forests in isolated locations. There is also one Juniperus excelsa forest, which although affected in the past by selective logging and pasturing, still preserves the largest species locality on the Balkan Peninsula with trees often exceeding 150-200 years. Old-growth beech forests are characterized by numerous small-sized gaps. Dead wood amount largely varies depending of site condition and past disturbances but rarely exceeds 100 m3/ha. DBH distributions resemble a rotated sigmoidal curve (Zlatanov et al. 2013). Old-growth Picea-dominated forests are characterized by younger and older patches resulting from windthrows and rarely fires of various sizes. Dead wood often exceeds 70-100 m3/ha. DBH distribution is resembles J-reversed. Typical for old-growth pine forests in the Pirin Mts. is high number of live old and dead trees with DBH often exceeding 100 cm and age > 500. Most important disturbances were fires, avalanches and rarely windthrows (Panayotov et al. 2017). Numerous fire traces in old Pinus nigra forests show that they were shaped by periodic fires. However, present day fire exclusion and past management guide dynamics towards increase of deciduous species in the understory. The total amount of deadwood rarely exceeds 30-40 m3/ha. The biggest threat to old-growth forests in Bulgaria is logging, including the potentially desired sanitary fellings in National Parks. In few locations conflicts arise also from desires to expand tourist infrastructure in old-growth forests. References: 1. Panayotov et al., 2017. Abiotic disturbances in Bulgarian mountain coniferous forests - an overview. Forest Ecology and Management, 388:13-28 2. Zlatanov et al., 2013. Index for identification and evaluation of old-growth forests in Bulgaria. Forest science, 17-28