There are five nature reserves in Kraków with a total area of 48.6 ha (120 acres). Smaller green zones constitute parts of the Kraków-Częstochowa Upland Jurassic Landscape Parks' Board, which deals with the protection areas of the Polish Jura. Under its jurisdiction are: the Bielany-Tyniec Landscape Park (Park Bielańsko-Tyniecki), Tenczynek Landscape Park (Park Tencziński) and Kraków Valleys Landscape Park (Park Krajobrazowy Dolinki Krakowskie), with their watersheds. All natural reserves of the Polish Jura Chain are part of the CORINE biotopes programme due to their unique flora, fauna, geomorphology and landscape. The western part of Kraków constitutes the so-called Obszar Krakowski ecological network, including the ecological corridor of the Vistula river. The southern slopes of limestone hills provide conditions for the development of thermophilous vegetation, grasslands and scrubs.