Spatio-temporal flowering patterns in Mediterranean Poaceae. A community study in SW Spain

J. Cebrino, J. L. García-Castaño, E. Domínguez-Vilches, C. Galán

This study focused on phenological timing and spatial patterns in 30 Poaceae species flowering in spring in different types of plant cover (scrub, riverbank and pasture). Grass community composition was studied, and the influence of species and plant cover on the start date and duration of flowering was assessed from March to June in both 2014 and 2015. Twenty-nine sampling sites were selected for phenological monitoring using the BBCH scale. Data were subjected to GLMM analyses. Binary discriminant analysis revealed differences in grass community composition as a function of plant cover type; scrub cover comprised a considerably larger number of species than those in riverbank and pasture. Moreover, more species diversity was observed in 2014 than in 2015 with a drier and stressed pre-flowering period. Differences on phenology were also recorded between plant cover types and study years. Species in pasture and riverbank flowered before (113.4 days; 116.1 days) than species in scrub (120.9 days), being these species with shorter flowering length because they are more exposed to the characteristic of the Mediterranean region during the summer. In general, flowering onset occurred later in 2014 (118.2 days) than in 2015 (115.8 days), probably attributable to precipitation occurring during March. On the other hand, spatial autocorrelation within some cover types has been observed, showing spatial patterns exist at a smaller scale. The findings of this study contribute to a better understanding of grass phenology in different environments.