Marcelo Cabido

The ReSurveyChaMon dataset provides a unique set of resurveyed vegetation plots spanning the sharp ecological transition between the Arid Chaco woodlands and the Monte steppe in central-western Argentina. The original plots were established in 1990 along a 300-km east-west transect covering a strong precipitation gradient, from xerophytic woodlands to desert shrublands, and were resurveyed in 2025 using the same protocol and plot size. In total, 104 vegetation plots are included in the dataset (52 original and 52 resurveyed). The dataset contains 164 vascular plant taxa from 113 genera and 41 families, with Poaceae, Fabaceae, and Cactaceae being the richest families. Species were assigned to life forms and chorotypes, and their native and endemic status (4 non-native and 39 endemic taxa) was also documented. All plots have been georeferenced, allowing integration with remote sensing and environmental data for future temporal and spatial analyses. ReSurveyChaMon offers an unprecedented opportunity to explore fine-scale vegetation dynamics across one of South America’s least studied dryland regions and provides a valuable baseline for biodiversity monitoring, conservation planning, and assessment of climate- and land-use-driven changes in arid and semi-arid ecosystems.

Question: We address the following questions: (1) which are the main plant communities in montane grasslands in central Argentina; (2) do those communities differ in terms of floristic composition, endemisms, chorotypes and life forms; and (3) which are the major environmental variables (climatic, topographic and edaphic) associated with the heterogeneity of the vegetation?Location: Pampean Mountains (Sierras Pampeanas), Córdoba Province, central Argentina, an area of ca. 37,000 km².Methods: The survey was based on a data set comprising 746 relevés and 822 vascular plant species, collected in accordance with the Braun‐Blanquet sampling method. The data were classified using the hierarchical ISOmetric feature mapping and Partitioning Around Medoids, and ordinated through isometric feature mapping (ISOPAM). The environmental variables were related to the ISOPAM ordination.Results: The ISOPAM classification identified two clusters, five vegetation types and 17 plant communities, which were distributed across different elevations. There were notable differences in the diagnostic species, average percentages of endemic species, chorotypes and life forms among the various vegetation types and plant communities. The primary gradient in grassland vegetation was found to be associated with elevation and related climatic variables.Conclusions: The study provides valuable insights into the montane grasslands of the Sierras Pampeanas in central Argentina. It presents a comprehensive classification of the region's grasslands, including tall tussock grasslands, humid grasslands, stony grasslands, and grasslands with scattered shrubs and trees. Each recognized unit is distinguished by diagnostic species and a distinct floristic composition. Our findings emphasize a significant division between grasslands at higher elevation, abundant in Andean species, and Piedmont and shrubby grasslands at lower elevations, characterized by a higher prevalence of Chacoan and other Neotropical species. Grassland vegetation in other regions of the Sierras Pampeanas remains poorly studied, requiring additional research to determine the syntaxonomic position of this vegetation.

Aims: We address the following questions: 1) Which are the main vegetation types that currently occur in the Arid Chaco? 2) Do those vegetation types differ in terms of floristic composition, endemism, chorotypes and life forms? and 3) Is there any spatial association between the vegetation types and the environmental heterogeneity of the Arid Chaco?Study area: The southwestern extreme of the Gran Chaco, in Central-Western Argentina.Methods: The survey was based on a dataset comprising 654 relevés collected according to the Braun-Blanquet method. Data were classified by the hierarchical ISOmetric feature mapping and Partition Around Medoids (ISOPAM), and ordinated through isometric feature mapping (ISOMAP). Bioclimatic and edaphic variables were related to the ISOMAP ordination.Results: We recorded 439 vascular plant species, 62 endemic at the national level and 22 endemic species restricted to the study and surrounding environments in Central-Western Argentina. A total of nine vegetation types, belonging to four major clusters, were identified. The most prominent chorotypes included species distributed in the Chaco region and in the Arid Chaco/Monte phytogeographic units. The predominant life forms were micro- and nano-phanerophytes, followed by hemicryptophytes, chamaephytes and mesophanerophytes.Conclusions: Major results highlighted that xerophytic shrublands are the most common vegetation types in this area as a result of the historical and present use, while old growth forests were constrained to areas with low anthropogenic disturbance in the last decades or to protected areas. Most vegetation types (with the exception of halophytic environments) are poorly differentiated from a floristic point of view; however, they clearly differ in physiognomy. The floristic composition of the vegetation types described revealed numerous species in common with other sectors of the Chaco of northern Argentina, Bolivia and Paraguay. Although the number of species restricted to the Arid Chaco was quite low, the most relevant chorotype included species with Western and Eastern Chaco distribution, conferring a clear Chaquenian identity to this area and discriminating it from other phytogeographic units.Taxonomic reference: Catálogo de las Plantas Vasculares del Cono Sur (Zuloaga et al. 2008) and its online update (http://www.darwin.edu.ar).Abbreviations: ISOMAP = isometric feature mapping; ISOPAM = isometric partitioning around medoids.

The ArgVeg is a repository of vegetation-plots data registered in the Global Index of Vegetation Databases (GIVD ID: SA-AR-002). This report presents its main characteristics, potential uses, and future perspectives. In September 2022, the database contained 1092 vegetation-plot records, including 1184 valid native and non-native vascular plants. The database covers the main vegetation types of nine vegetation units of the Chaco, Espinal and Pampean phytogeographic provinces in central Argentina. Those types include native forests, shrublands, grasslands, halophytic vegetation and non-native woody communities present in either lowlands or mountain areas. This database represents a significant improvement in the availability of floristic information from subtropical and warm temperate areas in South America, which still represents a major knowledge gap worldwide. ArgVeg reflects the outstanding plant diversity of central Argentina and it is managed by the Plant Ecology and Phytogeography Group at the Multidisciplinary Institute of Plant Biology (Córdoba, Argentina). Not only the high biodiversity but also the complex landscape heterogeneity are the most important characteristics of the vegetation in this region. We hope to increase the number of plots in the near future and to strengthen regional and global networks to enhance the conservation and management of these endangered ecosystems.

Aims: Classification of plant communities and identification of their diagnostic species in different types of rocky outcrops in mountains from Central Argentina. We also explored how these plant communities differ in their endemisms, chorotypes and non‐natives species composition, as well as in rock chemistry, elevation and climatic variables.Location: Córdoba Province, Central Argentina.Methods: The study was based on 505 phytosociological relevés collected from 2009 to 2019 using the Braun‐Blanquet cover‐abundance scale. The hierarchical ISOmetric feature mapping and Partition Around Medoids (ISOPAM) analysis was applied. The vegetation matrix was ordinated through isometric feature mapping (ISOMAP), and the geochemical and bioclimatic variables were related to the ISOMAP ordination.Results: We identified 14 plant communities distributed in three main clusters. We recorded 59 endemic species at the national level and 28 narrow endemics, restricted to the study area and nearby mountains. The number of non‐native plants was relatively low (26 species). Perennial herbs (221 species), grasses (97 species) and shrubs (68 species) were the most prominent life forms. Plant communities were associated with rock chemistry (carbonate and acidic rocks), and also with elevation and climatic variables.Conclusion: This study highlights the remarkable heterogeneity of outcrop vegetation in Central Argentina. It reveals that elevation and rock type (geochemical composition) were relevant factors associated with the floristic composition of plant communities and also, that outcrop habitats comprise a high level of endemisms, as well as a low number of non‐native species, suggesting a high value for the conservation of local and regional biodiversity.

Introducción y objetivos: Un mapa de vegetación detallado y actualizado es clave para el ordenamiento territorial. Dada la necesidad de un ordenamiento para las Sierras de Córdoba, nos propusimos: confeccionar un mapa de vegetación de estas montañas; describir la vegetación de las clases identificadas; interpretar su distribución a lo largo del gradiente altitudinal y discutir las implicancias para el ordenamiento territorial. M&M: Construimos un mapa preliminar a partir de imágenes satelitales e información de campo, donde discriminamos 14 unidades de vegetación. Luego de hacer un control a campo, elaboramos el mapa final, agrupando las unidades de vegetación en siete clases. Resultados: En el mapa final identificamos: bosques nativos, bosques exóticos, matorrales nativos, pajonales, céspedes, pastizales con roca y/o suelo desnudo y roquedales. Estas clases se discriminaron con una precisión general del 82,6%. Además, separamos cuerpos de agua, zonas inundables, cultivos y zonas urbanas. Los matorrales, que fueron la clase más extendida, abarcaron un 37% del paisaje, le siguieron los cultivos, que cubrieron un 23% del territorio. Los bosques nativos sólo ocuparon un 5,5% del área. Matorrales y bosques disminuyeron a lo largo del gradiente altitudinal, mientras que pastizales y roquedales aumentaron. Conclusiones: Sugerimos que un ordenamiento territorial de las montañas debería promover la restauración de los bosques nativos hasta ocupar un 20-40% del paisaje, el control del avance de las zonas urbanas y cultivos, y el manejo de especies exóticas invasoras para limitar su expansión sobre las fisonomías nativas.

Introducción y Objetivos: Las montañas concentran gran parte de la biodiversidad del planeta y brindan importantes beneficios al ser humano. Con el objetivo de generar una herramienta clave para el manejo sostenible de los ecosistemas de montaña de Córdoba, nos propusimos presentar una lista exhaustiva de plantas vasculares y sus rangos altitudinales. M&M: Recopilamos 669 censos florísticos completos y 1178 inventarios parciales realizados a campo desde 2005 hasta 2020. Resultados: Registramos 1069 especies de plantas: 147 exóticas, 143 endémicas de Argentina, 25 endémicas de Córdoba y San Luis y 19 endémicas de Córdoba. La mayoría de las especies encuentran su mediana altitudinal por debajo de los 1000 m. El recambio de especies hasta los 1250 msnm es lento, pero a partir de esta altitud comienza a acelerarse, y continúa de forma similar hasta el extremo más alto del gradiente. El 46% de las especies registradas han sido reportadas como medicinales, de ellas, 79 son exóticas, 36 endémicas de Argentina, dos endémicas de Córdoba y San Luis y dos exclusivas de Córdoba. Conclusiones: El listado incluye el 60% de las especies citadas para Córdoba y el 65.5% de la flora medicinal registrada para la provincia. El extremo superior de las montañas, que representa menos del 10% de la superficie, concentra la mayor proporción y diversidad de especies endémicas del centro de Argentina. Nuestros resultados muestran la importancia de estas montañas para la conservación y el manejo sostenible de la biodiversidad de Córdoba, y representan una línea de base para futuros estudios.

Aims: The native woody vegetation from the Espinal phytogeographic province in central Argentina, found in subtropical-warm temperate climates, represents part of the southernmost seasonally dry forest in South America. Although this vegetation has been studied for over a century, a complete phytosociological survey is still needed. This lack of knowledge makes its spatial delimitation and the establishment of efficient conservation strategies particularly difficult. The main goals of this study were to classify these forests and assess their current forest cover and to better define the extent of the Espinal phytogeographic province in Córdoba region, central Argentina. Study area: Espinal Phytogeographic Province in Córdoba region, central Argentina (ca. 101,500 km²). Methods: We sampled 122 stands following the principles of the Zürich-Montpellier School of phytosociology; relevés were classified through the ISOPAM hierarchical analysis. The extent of the Espinal phytogeographic province was established by overlaying previous vegetation maps, and a map showing the current distribution of forest patches was constructed based on a supervised classification of Landsat images. Results: Four woody vegetation types of seasonally dry subtropical forest were identified based on the fidelity and the abundance of diagnostic species: (1) Aspidosperma quebracho-blanco forest; (2) Zanthoxylum coco forest; (3) Geoffroea decorticans forest; and (4) Prosopis caldenia forest. These vegetation types were segregated along gradients of temperature and precipitation seasonality and soil-texture and sodium content. The remaining forest patches represent 3.43% of the extent of the Espinal province in Córdoba region of which only 1.05% is represented in protected areas. Conclusions: We present a classification of the Espinal forest based on a complete floristic survey. Despite the dramatic forest loss reported, our results show that some forest patches representative of the Espinal are still likely to be found in the area. However, urgent measures should be taken to establish new protected natural areas in order to preserve the last remaining forest patches. Taxonomic reference: Catálogo de las Plantas Vasculares del Cono Sur (Zuloaga et al. 2008) and its online update (http://www.darwin.edu.ar). Abbreviations: ISOMAP = isometric feature mapping; ISOPAM = isometric partitioning around medoids.

Land-cover changes are driven by different combinations of biophysical, economic, and cultural drivers that are acting at different scales. We aimed to (1) analyze trends in land use and land cover changes (conversion, abandonment, forest persistence) in the dry Chaco in central Argentina (1979 to 2010), and (2) examine how physical and socio-economic drivers have influenced those changes. Based on Landsat data, we obtained the proportion of 16 classes of land cover changes for 81 individual circular samples. We performed a Principal Component Analysis (PCA) to identify the main trends of change across the whole region. To explore the relationships between the changes in land cover and drivers, we developed a GIS comprising thematic maps representing the different drivers. The drivers were first correlated with the two first PCA axes, and in a second approximation were subjected to multiple regression analyses. We obtained in this way the best model to explain each PCA axis. The highest conversion, as indicated by PCA axis 1, was experienced by flat areas close to roads and with the highest annual rainfall. Besides agricultural expansion that was triggered by precipitation increase as a major driver of forest conversion, changes that were observed during the period 1979–2010, may have also been influenced by several other driving forces acting at different spatial scales and contexts.

Questions: Most vegetation descriptions tacitly assume that floristic composition and physiognomy are tightly linked. However, the two vegetation properties may not respond in a similar way to environmental and disturbance gradients, leading to uninformed management planning and difficulties when attempting to restore degraded ecosystems. In this context, we addressed two main questions: (1) how close are relations between floristic and physiognomic types as defined by numerical vegetation classification in mountain ecosystems; and (2) how are floristic and physiognomic types distributed along the elevation gradient?Location: Central mountains of Argentina, between 500 and 1700 m a.s.l.Methods: We selected 437 sites where we performed complete floristic and physiognomic relevés. We classified eight physiognomic and eight floristic types. We tested the relationship between the two classifications through a chi square analysis. We tested the association between elevation and each physiognomic and floristic type with random permutations.Results: In general, floristic types were significantly and positively associated with more than one physiognomic type and vice versa. Physiognomic and floristic types responded differently to the elevation gradient. Floristic types were restricted to different sections of the gradient, although having large overlap among them. In contrast, seven out of the eight physiognomic types did not show elevation restriction, being distributed along the complete elevation gradient. The open low woodland with shrubs was the only restricted physiognomy, significantly absent from the upper part of the gradient.Conclusions: We highlight the importance of considering the two vegetation properties independently when characterizing vegetation patterns in heterogeneous systems, since they show decoupled responses to environmental gradients. We note that the assumption of a direct link between floristic composition and physiognomy may induce bias into the understanding of vegetation patterns and processes. Hence, we encourage managers and restoration practitioners to consider the complete range of possible physiognomic types under each floristic type.