Handbook of standardized protocols for collecting plant modularity traits

Abstract Plant modularity traits relevant to functions of on-spot persistence, space occupancy, resprouting after disturbance, as well as resource storage, sharing, and foraging have been underrepresented in functional ecology so far. This knowledge gap exists for multiple reasons. First, these functions and related traits have been considered less important than others (e.g., resource economics, organ-based traits). Second, collecting data for modularity traits can be difficult. Third, as a consequence of the previous points, there is a lack of standardized collection protocols. We now feel the time is ripe to provide a solid conceptual and terminological framework together with comparable protocols for plant modularity traits that can be applicable across species, regions and biomes. We identify a suite of 14 key traits, which are assembled into five groups. We discuss the functional relevance of each trait, supplying effective guidelines to assist in the use and selection of the most suitable traits in relation to specific research tasks. Finally, we are convinced that the systematic study and widespread assessment of plant modularity traits could bridge this knowledge gap. As a result, previously overlooked key functions could be incorporated into the functional ecology research-agenda, thus providing a more comprehensive understanding of plant and ecosystem functioning.