Environmental variability of urban endangered wetlands of western central Argentina (Mendoza, 33°S) during the last 2200 yrs.

RÍOS L.D.; DE PORRAS M.E.; MOREIRAS S.M.; GÓMEZ L.; D´AMBROSIO S.

Encuentro; IAL-IPA 2022 joint meeting; 2022

Wetlands located in arid and semi-arid regions are hot spots of biodiversity and play a key role for migrating species. In eastern Mendoza (western central Argentina) exists a series of wetlands which according to historical documents were key not just for plants and animals but for native human groups as a source of resources for survival. However, in the last 100 yrs, changes in these wetlands watersheds summed to the development of extensive and intensive agriculture as well as urbanization have seriously affected their dynamics up to dry them seasonally. Therefore, this paper aims to disentangle the environmental variability of one of the Arroyo Tulumaya wetlands, the laguna El Viborón (LVI, 32° 53' 36.49" S & 68° 36' 40.76" W), during the last 2200 yrs in order to provide a long term picture of its dynamics to be applied on their proper management and conservation. The pollen record of a 0.7m-long core retrieved from a coastal area of LVI was analyzed. It is dominated by azonal pollen types such as Poaceae, Cyperaceae, Juncaceae, Amaranthaceae and Asteraceae subf. Asteroideae and reflects four main phases. Phase I, starting at 2200 cal yrs BP, reveals slightly wetter than present conditions followed by desiccation of the coastal area of the LVI under modern levels of the lagoon during Phase II. Phase III was the wettest phase during the last 2200 cal yrs BP which turned into the driest part of the whole record at the beginning of Phase IV. Since then, a gradual increase in moisture and plant diversity occurred also showing the appearance of exotic pollen types around 1929 AD. Phase IV changes, however, would be related to human activities as the establishment of a private fishing club for tourism and sport activities by this age.Acknowledgements: PICT 2019-3426; ANLAC; Proyecto PIO.