Ecosystem services show us fundamental importance of biodiversity although magnitude of the importance of biodiversity might be locally different for each service. In order to derive benefits from ecosystems by conserving forest biodiversity, we need scientific studies to determine quantities of ecosystem services, understand the functional species and relationships that supply ecosystem services, and understand the environmental variables to which the functional species or group responds. We also need to understand which ecosystem service might be expected at different scales: carbon sequestration and climate regulation occur at the global scale, while crop pollination and pest and disease control occur at the scale of the management unit. Therefore, we should develop assessment methods to assess forest ecosystem services at at the different scales: management unit, national, and regional scales. For example, while yield from a pollinated crop/ pollinator assemblage is a potential indicator, a habitat assessment of pollinators as a coarse filter indicator could be more practical.