Evaluating the distribution of plant life-history traits in relation to current and historical landscape configurations

1 In north European rural landscapes, abandonment of small farms and agricultural intensification have led to a decline in semi-natural grassland, with associated biodiversity loss. Although species richness response to land-use change in rural landscapes is relatively well studied, few have examined its effects on plant species composition over time. 2 In this study, four life-history traits associated with spatiotemporal dispersal were analysed: seed size, seed dispersal attributes (e.g. awns, wings), seed bank persistence and plant longevity (annuals, perennial with and without clonal ability). I investigated how differences in distribution of these traits among plants in semi-natural grasslands are related to current and historical landscape configuration. 3 The distributions of two out of the four investigated traits, longevity and seed bank persistence, were correlated with grassland connectivity and area, whereas seed size and seed dispersal attributes were not. The proportion of short-lived plants was positively associated with current grassland connectivity and grassland area, whereas long-lived species, with and without clonal ability, were unrelated to current grassland connectivity and area. 4 In contrast, short-lived plants were not affected by historical grassland connectivity, but the proportion of long-lived clonal plants was negatively associated with high historical grassland connectivity and large grassland area. In addition, the proportion of species with long persistence in the seed bank was negatively associated with historical grassland connectivity. 5 The result suggests that there are two main strategies to persist in response to landscape fragmentation: either persist in the seed bank or disperse vegetatively. The higher sensitivity to isolation among short-lived plants and plants without clonal ability calls attention to the importance of considering life-history traits to understand plant community dynamics fully over time. In the long term, reduction in historical connectivity and grassland area will thus create a grassland community dominated by clonal long-lived plants and plants with a persistent seed bank. 6 This study shows that both spatial and temporal effects of landscape configuration are important factors structuring local plant species composition in grasslands. The results bring important insights to our understanding of large-scale ecological processes, and are also highly relevant to biodiversity conservation in fragmented agricultural landscapes worldwide.