Vascular flora of Tuškanac Forest Park (Zagreb, Croatia)

Tuškanac Forest Park has been floristically studied over the past 15 years, but most extensively and systematically during the year 2021. Tuškanac Forest Park is a natural treasure in the center of Zagreb City. This oblong 150-year-old stand of oak, common beech, and hornbeam is a natural extension of the vegetation of Mount Medvednica and descends almost to Zagreb's main street (Ilica). A total of 173 vascular plant taxa were recorded (62 families and 131 genera). The largest part of the flora consists of Angiospermae (163 taxa; 94.2 %), followed by Monilophyta (6 taxa; 3.5%) and Gymnospermae (4 taxa; 2.3%). Rosaceae is the richest family with 14 taxa (8.1%), followed by Asteraceae sensu lato (13 taxa; 7.5%), Poaceae (11 taxa; 6.4%), Lamiaceae (9 taxa; 5.2%) and Fabaceae (8 taxa; 4.6%). The highest percentage of recorded plants are hemicryptophytes (41.0%) and phanerophytes (27.7%). The analysis of chorotypes shows that the Eurasian floral elements dominate (50.9%), followed by European (18.5%) and Mediterranean elements (8.1%). Urbanophobic (45.3%) significantly outnumber urbanophilic taxa (8.7%). A “close to nature“ environmental condition is additionally confirmed by the low values calculated for indicators of anthropogenisation and by the low share of alien flora (27 taxa; 15.6%). The following invasive alien taxa grow in the study site: Ailanthus altissima, Duchesnea indica, Erigeron annuus, Parthenocissus quinquefolia, Phytolacca americana, Robinia pseudoacacia and Veronica persica. According to IUCN categories, only two taxa belong to threatened categories: Taxus baccata and Lilium martagon are vulnerable (VU) and both taxa are strictly protected in Croatia.