|Heubes, J; Retzer, V; Schmidtlein, S; Beierkuhnlein, C: Historical land use explains current distribution of calcareous grassland species, Folia Geobotanica, 46(1), 1-16 (2011)|
In this study we analyzed if characteristic calcareous grassland species persist in forest habitats after land use change. Furthermore, we investigated whether the current distribution of such species is related to historical land use of the mid-19th century. Current distributions of nine calcareous grassland species were recorded in a region of Upper Franconia, Germany. Historical (up to 1850) and current land-use data were analyzed using historical maps and aerial photographs. To study the effects of historical land use in current species distributions, we used Generalized Estimating Equations (GEE) and ANOVA, accounting for spatial autocorrelation. Variance partitioning was applied to separate the influence of historical versus current land use. On average 26% of the recorded grassland species occurrences are located in sub-optimal forest habitats. Grassland populations are likely to persist in forest for at least 50 years. Even though current land use explains a higher proportion of the variation in species distribution than historical land use alone, model fit could be significantly improved (P < 0.001) considering the historical component. We conclude that consideration of historical land use is essential to understand the current grassland species distributions and may be of general importance for perennial species of temperate grasslands. In addition, historical legacy has far-reaching implications for conservation biology in terms of realistic assessments of species threat status in present landscapes.