Plant functional traits shape multiple ecosystem services, their trade-offs and synergies in grasslands.
Functional traits offer promising avenues to investigate how community composition and diversity define ecosystem functioning and service delivery. In recent years, many empirical studies on the importance of functional traits for ecosystem service provisioning have been undertaken, but a general understanding and synthesis of results is lacking for many ecosystems. Here we focus on temperate grasslands and present a systematic literature review synthesizing how plant functional traits are interrelated with ecosystem services. Based on 108 studies, we identified a core set of 40 functional traits and 11 ecosystem services. Several of these traits were only linked to one, while 75% of traits were linked to two or more ecosystem services. We found that trait-specific constraints can lead to both synergies and trade-offs in the supply of multiple ecosystem services. For instance, synergies between biomass production and climate regulation can be achieved by changing morphometric root traits such as increasing root diameter, tissue density or shoot to root ratio. On the other hand, supporting fast-growing exploitative species characterized by high specific leaf area and nitrogen content typically leads to trade-offs between fodder quality and water purification. Synthesis and applications. By applying network analysis, we found five groups of ecosystem services sharing common functional traits. Within and among these groups, we identified trade-offs among traits as well as among services and found options for synergies. These can be particularly useful in landscape planning, and when management aims focus on maintaining multifunctionality of ecosystems and maximizing corresponding ecosystem service delivery.