Variations in the coverage of biological soil crusts along a gradient of aridity in the center-west of argentina

Abstract

18The biological soil crusts (biocrust) play a fundamental role in the arid and semiarid areas of 19 South America. However, little attention has been paid to the distribution and coverage of them. In 20 Argentina, studies about biocrust are still scarce. The goal of this contribution is to analyze the 21 coverage of the biocrust and each of the functional component along a gradient of aridity in the center-22 west of Argentina. The gradient included three differentiated sites: semiarid, arid, and hyperarid sites. 23 The coverage was recorded using the Point-quadrat method on 30 transects through a gradient 24 consisting of three sites: semiarid, arid, and hyper-arid sites. The arid site was the system with the 25 highest coverage of biocrust followed by the hyper-arid site. The semiarid site had the lowest values 26 of coverage and showed significant differences among the three systems were found. Cyanobacteria's 27 dominate in the hyper-arid site. On the other hand, cyanobacteria and lichens were dominant in the 28 arid site. The coverage of studied organisms showed variations in the semiarid site. These results 29 support the idea that the coverage has a strong relationship with the features of the studied ecosystem 30 and the environmental factors both at a mesoscale and a microscale in a determined community. 31

Organizing a global list of cyanobacteria and algae from soil biocrusts evidenced great geographic and taxonomic gaps

“…In relation to the characteristics of the environments where biocrusts are found, our data compilation shows occurrences from extremely dry to highly humid environments (Castillo-Monroy et al 2016 , Navas Romero et al 2019 , Hakkoum et al 2020 , Samolov et al 2020 ). However, information on environmental characteristics and species occurrence seems to be limited, since there are more studies in arid and semiarid climate, and almost all genera were reported for these regions (Román et al 2018 , Williams et al 2018 , Roncero-Ramos et al 2019 , Szyja et al 2019 , Romero et al 2020, Zhao et al 2021 ).…”