Differences in plant trait distribution in semi-natural grassland habitats of Sweden

Abstract: Habitat type has been suggested to be a major factor contributing to differencesin plant trait distribution of grassland habitats. Land use changes in agricultural landscapes have affected the available habitats and the dispersal ability of plants, which may effect plant trait diversity of agricultural landscapes. Little is also known about the effects of landscape openness on plant trait diversity. This study analysed differences in plant traits between different semi-natural grassland habitats in agricultural landscapes in four different regions in Sweden: Skåne, Södermanland, Gävleborg, and Norrbotten. The following research questions were used: (1) How does landscape openness (the amount of open andarable land found in a landscape) affect plant trait values collected from a new database in semi-natural grassland habitats in agricultural landscapes? (2) How does the type of habitat affect plant trait values in semi-natural grassland habitats in agricultural landscapes? (3) How does geographical location in Sweden affect plant trait values in semi-natural grassland habitats in agricultural landscapes? Overall 12 landscapes in each region were surveyed for plant data using 20 sample plots in each landscape. Trait values for biodiversity relevance, nectar production, nitrogen, phosphorus, grazing/mowing, soil disturbance, longevity, pollinator dependence, and seed dispenser were assigned for each plant species based on an external database, and average trait values were calculated for each of the studied traits in each sample. Kruskal-Wallis test andANOVA were performed on average trait values to identify differences between each habitat types and regions. Besides the effect of habitat type, the effect of openness in the landscape on the chosen traits was analysed with Spearman’s and Pearson’s correlations. The results revealed differences between habitat types in almost all studied traits: grazed habitats had plants with higher biodiversity relevance but lower nectar production. Differences were also found between the southern and northern regions. More open landscapes had plants with higher biodiversity relevance as well as higher tolerance for both nitrogen and phosphorus. Less open landscapes had higher tolerance for grazing/mowing and higher nectar production. The results of this study therefore support earlier findings of the importance of habitat in plant trait distribution of grassland habitats.