Biodiversity of Archaea and floral of two inland saltern ecosystems in the Alto Vinalopó Valley, Spain

Background. The extraction of salt from seawater by means of coastal solar salterns is a very well-described process. Moreover, the characterization of these environments from ecological, biochemical and microbiological perspectives has become a key focus for many research groups all over the world over the last 20 years. In countries such as Spain, there are several examples of coastal solar salterns (mainly on the Mediterranean coast) and inland solar salterns, from which sodium chloride is obtained for human consumption. However, studies focused on the characterization of inland solar salterns are scarce and both the archaeal diversity and the plant communities inhabiting these environments remain poorly described. Results. Two of the inland solar salterns (termed Redonda and Penalva), located in the Alto Vinalopó Valley (Alicante, Spain), were characterized regarding their geological and physico-chemical characteristics and their archaeal and botanical biodiversity. A preliminary eukaryotic diversity survey was also performed using saline water. The chemical characterization of the brine has revealed that the salted groundwater extracted to fill these inland solar salterns is thalassohaline. The plant communities living in this environment are dominated by Sarcocornia fruticosa (L.) A.J. Scott, Arthrocnemum macrostachyum (Moris) K. Koch, Suaeda vera Forsk. ex Gmelin (Amaranthaceae) and several species of Limonium (Mill) and Tamarix (L). Archaeal diversity was analyzed and compared by polymerase chain reaction (PCR)-based molecular phylogenetic techniques. Most of the sequences recovered from environmental DNA samples are affiliated with haloarchaeal genera such as Haloarcula, Halorubrum, Haloquadratum and Halobacterium, and with an unclassified member of the Halobacteriaceae. The eukaryote Dunaliella was also present in the samples. Conclusions. To our knowledge, this study constitutes the first analysis centered on inland solar salterns located in the southeastern region of Spain. The results obtained revealed that the salt deposits of this region have marine origins. Plant communities typical of salt marshes are present in this ecosystem and members of the Halobacteriaceae family can be easily detected in the microbial populations of these habitats. Possible origins of the haloarchaea detected in this study are discussed.

The Iron Age landscape of Alcoi Valley, eastern Iberia: Agricultural intensification and sociopolitical dynamics

New archaeological survey data are combined with previous evidence to examine the rural landscape during the Iberian Iron Age in the Valencia region of eastern Spain. One goal was to understand the settlement pattern and agricultural intensification through manuring. The second objective was to address the socioeconomic aspects of changes in the landscape. It is possible to trace the emergence of a hierarchical settlement pattern in the Iberian Iron Age in which large fortified settlements carried out the most important functions of control and exploitation of the territory, extending their authority over small rural villages and farmsteads. This pattern is associated with the complex socioeconomic structures and political organization of early Iberian states.

Soil characteristics in Doon Valley (north west Himalaya, India) by inversion of H/V spectral ratios from ambient noise measurements

Past and recent observations have shown that the local site conditions significantly affect the behavior of seismic waves and its potential to cause destructive earthquakes. Thus, seismic microzonation studies have become crucial for seismic hazard assessment, providing local soil characteristics that can help to evaluate the possible seismic effects. Among the different methods used for estimating the soil characteristics, the ones based on ambient noise measurements, such as the H/V technique, become a cheap, non-invasive and successful way for evaluating the soil properties along a studied area. In this work, ambient noise measurements were taken at 240 sites around the Doon Valley, India, in order to characterize the sediment deposits. First, the H/V analysis has been carried out to estimate the resonant frequencies along the valley. Subsequently, some of this H/V results have been inverted, using the neighborhood algorithm and the available geotechnical information, in order to provide an estimation of the S-wave velocity profiles at the studied sites. Using all these information, we have characterized the sedimentary deposits in different areas of the Doon Valley, providing the resonant frequency, the soil thickness, the mean S-wave velocity of the sediments, and the mean S-wave velocity in the uppermost 30 m.