Background/Question/Methods In spite of the increasing amount of information demostrating the importance of plant diversity in ecosystem functioning, data of its role in the generation of ecosystem services is limited. Data is readily available on the positive effects of plant diversity on the provision of ecosystems services, at the species level, and for the richness component but there is scarce or no information for other organization levels, and for other components of plant diversity. An assessment of expert knowledge allowed us to answer the question: What is the relationship between plant diversity and the provision of ecosystem services at landscape scales? In this study surveys of experts in the areas of biodiversity, ecosystem functioning and ecosystem services were used to evaluate the effect and relative importance of different levels of organization and components of plant diversity on the generation of 14 different services at the landscape scale, as well as the relative importance of plant diversity was examined in relation to abiotic factors. Results/Conclusions Of the 344 surveys sent to experts, 83 replies were received from across 27 countries in all five continents. The experts identified diversity of species within a community and diversity of communities within a landscape as the most important levels of organization for services generation; in both cases a positive relationship was acknowledged. Composition and number of species were found to be the most relevant components of the plant diversity with a positive effect on services, whereas water and nutrient availability were identified as the most important resources that modify service generation. The expert's survey allowed for the generation of rapid, reliable and detailed information about the relationship between plant diversity and services, opening the possibility for the generation of hypotheses to be further tested.