February 12-15, 2019 
Warsaw–Białowieża, PolandThe Białowieża Forest
The Białowieża Forest is a large (1500 km2) forest complex stretching over the Polish-Belarusian border (40% vs. 60%, respectively). This is the middle of the European lowlands (52º41'N and 23º52'E), the southern edge of the mixed (nemoral-boreal) forest zone containing native Norway spruce Picea abies which is present in all types of forest communities (Faliński 1986). The landscape of the region is flat, with the lowest point by river Narew (134 m a.s.l.) and the highest "peak" of Kazlinaya Gara (202 m a.s.l.) in Belarusian part of the forest. 
The temperate climate, with mean annual precipitation of 624 mm and mean annual temperature of +6.6 ºC (data from years 1952-2005) shows tendency to warm, especially during winter period.
The change in mean annual temperature since 1952 already reached the level of 1.3 ºC (Sparks et al. 2008) - more than mean global annual temperature change. Climate change already shows effects on organisms living in the forest: some birds species start nesting a few days earlier than 30 years ago (Wesołowski & Cholewa 2009), other species arrive from wintering sites up to a week earlier than they use to few decades ago (Mitrus 2005), early spring plants flower 10-14 days earlier than 50 years ago (Sparks et al. 2008).
The forest is famous for containing the last extensive fragments of close-to-natural forests in the temperate zone. It is a home to many species that are recently rare or extinct elsewhere ("relicts of primaeval forest"), which survived here due to continuity of forest cover for the last 12 thousand years (Latałowa et al. 2016) and close to 600 years long protection by Polish kings and Russian tsars. It includes the largest terrestrial European mammal, the European bison Bison bonasus. At the beginning of the twentieth century the first formal protected areas were established but on the other hand, commercial timber exploitation had started outside of them. Since then, most of the forest in the Polish part has been managed for timber (Wesołowski 2005; Latałowa et al. 2015). The Belarusian part (the border exists since 1944) used to be a zapovednik (1944-1956; the highest form on nature conservation is the Soviet Union), hunting reserve (1956-1992) and the national park since 1992.
A small portion of the forest (c. 47.5 km2) in the Polish part has been strictly protected (no intervention management) since 1921. This is recently the core area of the Białowieża National Park (BNP). The way of ecosystem functioning, existing within limits of the BNP are indicative of those that existed in European temperate primeval forests before their clearance and modification by silviculture.
The forest is a living museum and research laboratory, a 'window into the past' through which we can gain insights into the ecology, functioning and adaptations of temperate forest organisms. It differs from other European temperate forests by (inter alia): large size of trees, multistorey uneven-aged stands, species rich tree communities, large amount of standing and downed deadwood and uprooted trees, high abundance of tree cavities (potential hiding and nesting sites).
The future of this forest in the Polish part is still unsure. While the whole Belarusian part is protected in the State National Park "Belovezhskay Pushcha", only 16% of the forest in the Polish part is in the national park limits. The rest is managed by Polish National Forest Holding "State Forests" as a commercial timber forest, involving logging of the last patches of old growths outside the national park. This is a source of over 25 years long conflict over the management of this precious forest, as goals of silviculture are not in line with the level of naturalness of the forest. They are also in conflict with the goals of Natura 2000 (existing since 2006) or UNESCO World Heritage site (since 2014) covering the whole area in the Polish part.
