Plants metacommunity from temporary ponds

The database comprises a long-term survey of a plant metacommunity of temporary ponds. The metacommunity is located in a flat landscape surrounded by hills, where a maximum of 61 ponds, every year, are filled with water in winter and dry out in summer in the same spatial locations. Information on species occurrences at the sampling unit level was recorded since 2005 (until 2022 and continuous). 

The database includes: 

Species occurrences at the sampling unit level for 61 temporary ponds along 14 years (to be periodically updated). 
Species traits database and functional description of traits. 
Environmental information of each pond including connectivity, area, heterogeneity and hydroperiod.

Methods

Every spring since 2005, ponds have been sampled equidistantly using 20x20 cm quadrants on the major axis. On average, five quadrants were sampled in most ponds. However, to account for the range of pond areas, which exhibits differences in several orders of magnitude (from 6.6 m2 to 24,673 m2) when the quadrants were closer than two meters, the number of sampled units was reduced, and if the quadrants were more than 10 meters apart, then the number of sampled units was increased.

A species-by-trait matrix was constructed from a review of the literature and direct observations. The list of traits considered is presented, introducing their description and functional roles. Different traits related to dispersal strategy, competitive ability, drought resistance strategy, life history, and tolerance to stress were considered.

Environmental data. Community connectivity was quantified by two centrality metrics, degree, closeness, and betwenness estimated on a percolation graph, which is a network that connects all ponds with the minimum linkage Euclidean distance required for linkage. Degree centrality is the number of direct connections of a local pond with other ponds, and closeness centrality is the reciprocal of the average distances of a local pond with all the other ponds in the metacommunity, representing metrics of direct and global connectivity, respectively. The area of the pond was estimated as the area of an oval using the length of the major and minor axes of the ponds. The hydroperiod was estimated as the proportion of sampling times with water for sampling carried out between 2006 and 2009 when the ponds were visited several times. Heterogeneity was estimated as the number of 'islands', emergent mounds above water level, per meter of the main and minor axes of the ponds. The average environmental values during the sampling time were used.