Species traits are better determinants of mobility than management in a species‐rich meadow

Abstract

AbstractQuestionInter‐annual species mobility within a community might support species co‐existence in species‐rich ecosystems. We asked how species mobility within a highly diverse grassland community is affected by species traits and how external conditions (management) affect mobility.LocationSemi‐natural wet meadow in southern Bohemia, Czech Republic (48°57′ N, 14°36′ E, 510 m a.s.l.).MethodsA manipulative experiment comprising mowing, fertilization, and removal of the dominant species Molinia caerulea was established, in factorial design, in a semi‐natural species‐rich meadow in 1994. Rooting presence of all species was recorded in individual 0.1 m × 0.1 m cells grid within 0.5 m × 0.5 m permanently fixed quadrats. We used a 14‐year continuous time series to evaluate species persistence (ability to stay in a cell over time) in each plot, using the point correlation coefficient (V), and related persistence to different plant traits. At the community level we also determined mobility, as floristic dissimilarity of the individual cell and the whole 0.5 m × 0.5 m quadrat across contiguous years.ResultsThe differences in traits and mobility among species were remarkable: “sitters,” retaining their spatial position (e.g. Succisa pratensis, Carex umbrosa) had tougher leaves, usually had shoot generation overlap, a rosette and did not have effective clonal spreading; “travelers” (e.g. Lysimachia vulgaris, Lathyrus pratensis) changed their position frequently and had opposite traits. Of the experimental factors, only mowing affected mobility, increasing persistence, but all factors modified species mobility ranking slightly. Against expectation, species richness was negatively correlated with community mobility.ConclusionsA high degree of mobility in species‐rich meadows does not necessarily enhance diversity. However, a functional differentiation between more mobile and fixed species can be expected within co‐existing species. Species mobility is highly species‐specific and less affected by management.