The significance of the effort becomes clear when the global picture is considered. Over the last century, millions of vegetation plots have been recorded worldwide, together with vast amounts of associated environmental information. Yet the distribution of these records is strikingly uneven.

Europe, with its long tradition of classical phytosociological survey work, dominates the global holdings, and North America and Australia also contribute thousands of relevés. According to the Global Index of Vegetation-Plot Databases, South America and Africa are the continents least represented. Before electronic databases and digital communication tools existed, access to vegetation plot information at regional and global scales was extremely limited, and much of what was collected in South America ended up unpublished or buried in grey literature that never reached digital archives.

Argentina illustrates that problem acutely. Large numbers of floristic surveys have been carried out in the country, but most of this information remains inaccessible in unpublished reports or scattered documents. The urgency of compiling a national vegetation-plot database is heightened by the fact that Argentinian plant communities are currently highly threatened.

Central Argentina in particular harbours a diversity of vegetation that is extensively recognised, but that diversity is under pressure from multiple directions: the advance of the agricultural frontier, the spread of non-native species, and increasing urbanization. Against this backdrop, the compilers of ArgVeg set out to collect published and unpublished floristic information, georeference every vegetation plot, and analyse the spatial distribution of the different plant communities the records represent. The database has grown steadily since its inception.

ArgVeg began in 2017 with a set of vegetation plots published in studies from 1991 and 1994. By 2019, after the inclusion of further published plots and other unpublished surveys, it comprised 819 records. The current version encompasses 1,092 plots, with the latest update adding surveys published in 2020 and 2021 along with additional unpublished data.

Handling data from so many sources required careful standardisation. Because species abundances had been recorded on different scales, all data were transformed into a common percentage cover scale. Most surveys had originally used a continuous cover scale, but some followed the Braun-Blanquet ordinal scale, a classical method in vegetation science that ranks species abundance in categories.

Georeferencing presented its own challenges. In most cases, plot locations were recorded in the field with a GPS device. For the oldest plots, coordinates were inferred from locality descriptions and proximity to other georeferenced plots, an approach that proved impossible in only six of the 1,092 cases.

Species names were harmonised in September 2022 using the Taxonomic Name Resolution Service, an online tool that standardises plant nomenclature, applied with default settings. The content of the database reveals both the richness of central Argentine vegetation and the unevenness of what survives to be sampled. The plots span sampling areas from 9 to 400 square metres, with most plots measuring 400 square metres, followed by 16 square metres and 100 square metres.

The largest plots capture different physiognomic vegetation types, while the smaller ones correspond to grasslands, grazing lawns and rocky outcrops. The oldest plot dates to 1989, but the bulk of the data, 84 percent, was collected between 2004 and 2019. In total, the database includes 1,184 specific and infraspecific taxa, representing 54 percent of the vascular plants registered for Córdoba province.

Córdoba province encompasses three phytogeographic provinces under a subtropical seasonally dry climate, with annual precipitation declining from about 900 millimetres in the southeast to 450 millimetres in the northwest. The plots are distributed across all three provinces, but the largest proportion lies in the Chaco phytogeographic province, particularly in its mountain areas. That concentration is not accidental.

Most Pampean and Espinal vegetation has been replaced by crops, leaving only small remnants of natural and semi-natural vegetation in those units, so the surviving plots document what little remains. Within the Chaco, the database captures a striking elevational and climatic range. The Arid Chaco of the northwestern and western plains, receiving less than 500 millimetres of rain per year, holds 6.4 percent of the plots, mostly representing subtropical xerophytic shrublands and woodlands characterised by species such as Larrea divaricata, Senegalia gilliesii and Mimozyganthus carinatus.

The Semi-Arid Chaco of the northern lowlands, with 600 to 800 millimetres of annual precipitation, is represented by 4.8 percent of the plots; today less than 20 percent of that unit retains open to closed forest, the rest having been converted to agriculture. The Mountain Chaco, spanning roughly 500 to 1,700 metres above sea level, dominates the database with 48.2 percent of all plots, documenting a complex mosaic of native forests, shrublands and grasslands interspersed with non-native plantations. The Sub-Andean unit, from about 1,700 metres up to the mountain summits at 2,770 metres, contributes 30.5 percent of the plots, including native shrublands and forests of Polylepis australis set within a landscape of grasslands, rocky outcrops and grazing lawns.

Halophytic vegetation in saline depressions, dominated by succulent shrublands, accounts for 1.2 percent. The Espinal and Pampean provinces tell a starker story of transformation. In the Espinal, where forests and savannas dominated by Prosopis tree species were the potential vegetation, 88 percent of the area has been replaced by soybean and corn crops and grazing lands, and the remaining woody patches are threatened by invasions of non-native species such as the glossy privet, Ligustrum lucidum.

Only 7.3 percent of the database plots come from this province, split between the Southern Espinal with its Prosopis caldenia forest and the Central Espinal with low open forests of Geoffroea decorticans. The Pampean province fares worse still: temperate grasslands that once covered the southeastern lowlands are now 92 percent cropland, and invasive grasses and woody species add further pressure. Just 1.7 percent of the plots represent the Pampean units, and the Ondulate Pampa has no plots at all.

The compilers see ArgVeg as more than an archive. Because most plots carry geographic coordinates, they can be combined with environmental data or protected-area information for broader analyses, and the database offers an overall description of the diversity of current vegetation types in central Argentina that may serve as a key tool for nature conservation. Some plots sit in remnants of natural or semi-natural vegetation in one of the most threatened parts of the country, making them valuable for restoration planning, conservation and long-term vegetation monitoring.

Most plots are already included in sPlot, the global vegetation database, extending the reach of these Argentine records into worldwide comparative studies. The team plans to expand the geographic extent, increase sampling in poorly represented areas such as non-native woody vegetation, riparian zones and Pampean grasslands, and incorporate further published surveys to build a comprehensive overview of all major vegetation types in central Argentina. ArgVeg remains under constant development, tied to ongoing research projects, with data ownership retained by contributors and sharing decisions made individually for each request.

Subject of Research: A vegetation-plot database of central Argentina compiling floristic surveys across the Chaco, Espinal and Pampean phytogeographic provinces

Article Title: ArgVeg – Database of Central Argentina

Article References: Giorgis, M. A., Cabido, M. R., Cingolani, A. M., Palchetti, M. V., Zeballos, S. R., Cantero, J. J., & Acosta, A. T. R. (2022). ArgVeg – Database of Central Argentina. Vegetation Classification and Survey, 3, 223-230. https://doi.org/10.3897/vcs.94256

Image Credits: AI Generated

DOI: 10.3897/VCS.94256

Keywords: vegetation plots, ArgVeg, Argentina, Córdoba, phytosociology, Chaco, Espinal, Pampas, plant conservation, biodiversity database, sPlot, floristic surveys