We used this dataset to determine whether area and connectivity of temporary ponds can predict plant species diversity, and the diversity and abundance of different plant life histories within the ponds. The studied system is located in the Ciuc Basin of the Southeastern Carpathian Mountains, Romania.  We collected data on the macrophyte species diversity of 28 temporary ponds between 2006-2009. Plant species identified in the ponds were assigned into one of the social behaviour types proposed by Borhidi (1995), which describe plant-habitat interactions within a framework extended from Grime’s evolutionary life strategies (Grime 1988), as follows: competitors, stress tolerants (generalists or specialists) and ruderals (natural pioneers i.e., plants of habitats disturbed by natural factors, and plants of habitats disturbed by human factors, classified as either: disturbance tolerants, native weeds, naturalised crops, adventitious weeds, ruderal competitors, alien competitors). We expressed species diversity as observed species richness (total number of species) and Shannon diversity index, and abundance as cumulative vegetation cover, calculated for each pond and for each social behaviour type separately. We calculated pond area using the short and long axis of the ellipse that best approximated the pond shape. Pond connectivity with the Olt river was defined as the pond present and respectively past (preceding river regulation) geographic distance from the Olt river, measured between the pond GPS coordinate and the nearest point of the river.

Description of methods used for collection/generation of data: 

We collected data on the macrophyte species diversity of 28 temporary ponds in the Ciuc Basin (Romania, Southeastern Carpathians, Europe) using a stratified sampling. Each plant community identified in a pond was recorded with one phytosociological relevé in a 25 m² plot placed randomly within that community. Vascular species were identified at the species level and mosses at the genus level, and assigned to six cover classes by visual estimation (Braun-Blanquet, 1964). Plant communities were identified following (Coldea 1991, Sanda et al. 2008). A short report on the plant communities identified is available in Csergő and Demeter (2011).

We recorded the geographic coordinates of each pond in the WGS84 Coordinate Reference System using a GPS device. We calculated pond area using the short and long axis of the ellipse that best approximated the pond shape. We defined pond connectivity with the Olt river as the pond present and respectively past geographic distance from the Olt river, measured between the pond GPS coordinate and the nearest point of the river. For obtaining the past distance we used the digitised map of the Second Military Survey of the Habsburg Empire (1853-1858 and 1869-1870) accessed from https://www.arcanum.com (Timár et al. 2010). All geo-spatial operations were performed using QGIS Desktop 3.16.6. with GRASS 7.8.5 software.

References:

Csergő, A. M., & Demeter, L. (2011). The Conservation Value of Temporary Ponds in the Ciuc Basin (Transylvania, Romania) from a Vegetation Perspective. In B. Knowles (Ed.), Mountain hay meadows: hotspots of biodiversity and traditional culture. Retrieved from http://www.mountainhaymeadows.eu/online_publication/index.html

Braun-Blanquet, J. (1964). Pflanzensoziologie, Grundzüge der Vegetationskunde (3rd ed., Vol. 631). Berlin: Springer-Verlag.

Coldea, G. (1991). Prodrome des associations Vegetales des Carpates du Sud-Est (Carpates Roumanies). Documents Phytosociologiques, N.S. 13, 1–540.

Sanda, V., Öllerer, K., & Burescu, P. (2008). Fitocenozele din România. Sintaxonomie, structură, dinamică şi evoluţie. Ed. Ars Docendi, București. 537 pp.

Timár, G., Biszak, S., Székely, B., & Molnár, G. (2010). Digitized Maps of the Habsburg Military Surveys – Overview of the Project of ARCANUM Ltd. (Hungary). In M. Jobst (Ed.), Preservation in Digital Cartography. Lecture Notes in Geoinformation and Cartography (pp. 273–283). Berlin: Springer.

Methods for processing the data: 

In each phytosociological relevé we converted the six cover classes into percentages as follows: 0.5%, 5%, 17.5%, 37.5%, 62.5%, and 87.5%. 

We grouped the recorded species into one of the social behaviour types proposed by Borhidi (1995), which describe plant-habitat interactions within a framework extended from Grime’s evolutionary life strategies (Grime 1988), as follows: competitors, stress tolerants (generalists or specialists) and ruderals (natural pioneers i.e., plants of habitats disturbed by natural factors, and plants of habitats disturbed by human factors, classified as either: disturbance tolerants, native weeds, naturalised crops, adventitious weeds, ruderal competitors, alien competitors). To quantify plant diversity and abundance at the pond- level and for each social behaviour type within a pond, we first calculated a pond-level pooled species dataset, selecting the average cover value observed for each species across all plots within a pond. Using the pooled dataset, we expressed species diversity as observed species richness (total number of species) and Shannon diversity index. We expressed abundance as cumulative vegetation cover, calculated for each pond and for each social behaviour type separately. To make the abundance values of different social behaviour types comparable, we divided the cumulative cover of each social behaviour type within a pond by the total vegetation cover obtained for the respective pond. The diversity metrics were calculated using the vegan package in R (Oksanen et al. 2013).

References:

Borhidi, A. (1995). Social Behaviour Types of the Hungarian Flora, its Naturalness and Relative Ecological Indicator Values. Acta Botanica Hungarica, 39(January 1995), 97–181.

Grime, J. P. (1988). The C-S-R model of primary plant strategies — origins, implications and tests. In L. D. Gottlieb & S. K. Jain (Eds.), Plant Evolutionary Biology (pp. 371–393). https://doi.org/10.1007/978-94-009-1207-6_14

Oksanen, J., Blanchet, F. G., Kindt, R., Legendre, P., Minchin, P. R., O’Hara, R. B., … Wagner, H. (2013). Vegan: Community Ecology Package.

The spreadsheets can be opened in versions of Excel and R.