Modeling the potential distribution of floristic assemblages of high Andean wetlands dominated by Juncaceae and Cyperaceae in the Argentine Puna

Prepared by Elvira Casagranda & Andrea E. Izquierdo

View of the “Acay Sur” vega during one of the vegetation sampling campaigns. Photo credits: A.E. Izquierdo

Plant communities are the main biological factor determining the functional ecosystem processes of the systems. In the Puna, a highland desert from the Andes, vegas are important wetlands representing real oases in the arid soil matrix. Vegas occur in concave areas where the sediments are retained, and the water is close to the surface, promoting high diversity of plant communities. In these ecosystems, the typical cushion structures of the high Andean vegas are mainly dominated by specific plant species that promote soil formation, which modifies the landform and, at the same time, contributes to the retention and regulation of water flows. In the context of ongoing climate change, these ecosystems are considered highly vulnerable to the predicted changes in precipitation and temperature in the region.

A view of the typical cushions formed by Oxychloe andina in the “Barranca Blanca” vega. Photo credits: A.E. Izquierdo.

Our article aims to study the distribution of two previously described plant communities in the high Andean vegas of the Argentine Puna region. We modeled the distribution of two floristic types of vegas dominated by plants of the families Juncaceaea (Oxychloe andina) and Cyperaceae, respectively, which are important components of these ecosystems. For analysis, we used occurrence records of the plant communities and environmental data to create models that predict the potential distribution of the above-mentioned communities. We found that the distribution of these plant communities is influenced by several environmental factors, such as temperature, precipitation, and soil characteristics.

Detail of an individual of Oxychloe andina, the cushion-dominant species in Juncaceae vegas. Photo credits: A.E. Izquierdo.

Our results indicate that the communities dominated by Juncaceae are most likely to occur in higher elevation areas with higher humidity and lower temperatures, while vegas dominated by Cyperaceae tend to be located at lower elevation areas with lower humidity and higher temperatures. This distribution pattern highlights the vulnerability of these ecosystems to climate change scenarios which forecast an increase in temperature and lower precipitation, which may have implications for the conservation of these ecosystems.

Overall, this study provides important insights into the distribution and potential future changes of plant communities in the high Andean vegas of the Argentine Puna. Understanding which environmental variables determine the distribution of these plant community assemblages is key to informing conservation efforts and management practices for these important ecosystems.

This is a plain language summary of the paper of Casagranda and Izquierdo published in Vegetation Classification and Survey (