What is the future of Crno lake on Treskavica Mt. in Bosnia and Herzegovina?

Abstract

Crno jezero (1675 m a.s.l.) is an alpine lake on Treskavica Mt. in Bosnia and Herzegovina (BiH). We investigated the distribution and abundance of aquatic macrophytes in the lake after the standard BAS EN 15460:2009 and orthophotos that were taken by a drone at different heights (124, 80, 50, 20 m). Aquatic macrophytes were sampled on both the longitudinal and vertical profile of the lake, whereby the depth and temperature of water were measured by the Mares Quad dive computer. For the assessment of its ecological status, we used Macrophyte Nutrient Index for Ponds (M-NIP) and QGIS ver. 3.22.13. The most abundant macrophytes were: Equisetum fluviatile, Potamogeton alpinus, P. perfoliatus and Carex rostrata. By comparison of our results with the previous ones originating from 1954, we made a predictive model for the succession dynamics of macrophytic vegetation around the lake. In spite of that, calculated M-NIP classified the ecological status of Crno jezero as good. This research represents an original approach in the investigation of alpine lakes in BiH with the potential to be applied on a national scale as a contribution to global monitoring programs.