First insights into functional and taxonomic changes after three years of simulated extreme events in wet grasslands

Grasslands are an integral part of terrestrial land cover being highly biodiverse, semi-natural habitats. With the decline of this ecosystem due to direct human impacts, remaining grasslands are under increasing pressure from climate change. Thus, the main objective of our research was to determine the taxonomic and functional responses in grasslands under the influence of simulated extreme inundation and climate warming. The field experiment was conducted on translocated grassland plots in the Radzionków Botanical Garden. We analysed the response of vegetation with the use of plant functional trait changes related to persistence, growth rate, reproduction and competitive ability (specific leaf area, SLA; leaf dry matter content, LDMC; height; seed mass) and plant life strategies ( C , S , R ) using trait-based approach (community weighted means and functional diversity indices). The results showed increased temperature caused a significant increase in competitiveness ( C strategy) for all species and for the forb group counted separately, and a decrease in the ruderal strategy for the forb group. We found that the higher the hydration, the lower the species richness (more so at higher temperatures). In addition, we find that drought increases functional richness, mainly due to an increase in SLA and a higher proportion of forbs. Furthermore, warming decreases functional richness of graminoids and increases functional divergence of graminoids and forbs, especially in dry conditions. Our research indicates that climate change has a complex impact on plant diversity in European grasslands, highlighting the need for further exploration of these interactions to predict long-term effects on biodiversity and ecosystem functioning. • Higher hydration reduces species richness, especially at higher temperatures. • Drought increases forb functional richness, while warming reduces graminoid functional richness. • Additional irrigation and warming increase functional divergence. • Warming increases plant C strategy in grasslands. • Drought favors, while warming hinders, the R strategy of forbs.