Change of Species and Habitat Diversity in the Pannonian Region of Eastern Lower Austria over 170 Years: Using Herbarium Records as a Witness

Abstract

By dint of historical herbarium specimens, we show how changes in species and habitat diversity can be reviewed and correlated with historical events. Our work is based on a digital database of specimens of the BOKU herbarium (WHB), which can be assigned to the Pannonian region of eastern Lower Austria. The complete dataset ( n = 6655 specimens) was analyzed with the aid of statistical methods allowing computational elimination of collectors ' effects ( i.e. unbalanced collecting interests of collectors over time; multiple regression analysis, general linear model), from the first herbarium specimens (dating back to 1830) to the present. As a result, a significant decrease in the proportion of species of some habitats (above all water bodies and closely associated habitats, humid and wet meadows, fens and fen meadows, and nutrient poor grassland) was detected. For water-influenced habitats, this decrease correlates with the time of Danube regulation. Moreover, an increase in the proportion of species of ruderal sites was asserted during the observation period. The analysis procedure developed can be used for evaluation of major digitized herbaria in order to trace historical changes in species and habitat diversity.