Diversity and variation of the arachnid community from the Puna Ecoregion, Salta Province, Argentina. 17Th

GONZÁLEZ REYES, ANDREA X; OLIVO VERÓNICA,; CORRONCA, J. A.; GONZALO DANIEL, RUBIO

Congreso; 17Th International Arachnological Congress, Sao Paulo, Brazil; 2007

international Arachnological Society

Several ecoregions are represented in Salta province. There, the Puna is very important because it is a priority conservation area included in Global 200 (109 Central Andean Dry Puna conservation status = vulnerable). The Argentinean Puna has a low diversity value but a high percentage of endemism. Studies there are needed to obtain a baseline dataset for future comparative researches. The aim of this study is to analyze the arachnid diversity and its variation in different sites (3000 ñ 4000 m asl) and try to know if there are differences between them and along the year. The study was carried out in MuÒano locality. We consider three transect in different altitudes, separated by at least 4 km between them: the first site at 3705 m asl (24º 21.88íS 66º 05.76íW), the second site at 3861 m asl (24º 19.77íS 66º 06.68íW) and the third site at 3989 m asl (24º 18.24íS 66º 08.44íW). Arthropods were collected seasonally with pitfall traps (spring 2005 until winter 2006), by 10 traps on each sites with 7 days of activity. The material was identified into order, family and species/morphospecies using TAXIS3.5 software. Eleven thousand four hundred and eighty nine arthropods were collected and the arachnids represented 15% (1697 specimens) of the total. Acari was the most abundant (N = 1543, S = 12) group , but Araneae was the more diverse (N = 119, S = 26) group. The index values were: 1st site (S = 26, N = 532, D = 0.2093, Hí = 2.077, Jí = 0.6376) 2nd site (S = 33, N = 1028, D = 0.238, Hí = 1.984, Jí = 0.5676), and 3rd site (S = 16, N = 407, D = 0.333, Hí = 1.528, Jí = 0.551). The 1-2 sites did not show a significant difference in S, D and H¥. The 1-3 sites and the 2-3 sites showed significant differences between them. The similarity was high between the 1st and 2nd sites (Jaccard index = 0.595). Philodromidae was the dominant spider family in the 1st site, Orsolobidae in the 2nd and Dyctynidae in the 3rd site. Solifugae (Mummucidae) and scorpions (Bothriuridae) were more abundant in the 2nd site. The seasonal activity showed a great abundance of arachnid in summer. The high diversity of the 2nd site is explained by the vegetation heterogeneity and the texture and coverage of the soil