Om betydelsen av i vilken ordning arter introduceras till ängsväxtsamhällen

The order in which species arrive can have lasting effects on both individual species and communities as a whole. These "priority effects" occur when early-arriving species influence the success of those that arrive later. Understanding when and how priority effects occur can aid in the development of restoration methods, an increasingly critical goal as ecosystems face growing pressures from climate change, land-use change, and invasive species. This thesis investigates how the timing of species arrival affects community assembly in grasslands. Specifically, I used growth chamber and long-term field experiments to tests how plant traits modulate the strength of priority effects, both aboveground and below the soil surface. Further, the field experiments were duplicated across contrasting climates in order to test whether priority effects are site-dependent. The results show that priority effects are common and can strongly influence both individual species performance and community structure. Much of the variation in priority effect strength could be explained by species traits related to germination timing and competitive ability. The effects were also site-dependent, with stronger impacts observed in the boreal system. Additionally, sowing time itself, independent of arrival order, had significant consequences on plant community development. Together, these findings emphasize that in community assembly, timing is everything.