Diversity and variation of the arachnid community from the puna ecoregion, Salta Province, Argentina

GONZÁLEZ-REYES ANDREA; OLIVO VERÓNICA; CORRONCA JOSÉ; RUBIO GONZALO

Sao Paulo

Congreso; 17th International Congress of Arachnology; 2007

Several ecoregions are represented in Salta province. For them, the Puna is very important because it is a priority conservation area included in the Global 200 (109 Central Andean Dry Puna; conservation status= vulnerable). The Argentinean Puna has a low diversity value but a high percentage of endemism represented by unique flora and fauna. Studies on this area are a need to obtain a baseline dataset for future comparative researches. The aim of this study is to analyze the arachnid diversity and its variation between the 3000-4000masl in different sites with the purpose to know if there are a difference between them and along the year. The study was carried out in Muñano locality, Salta (Argentina) where we consider three transect in different altitude, separated by at least 4km between them: the first site at 3705masl (24º21.88’S 66º05.76’W), the second site at 3861masl (24º19.77’S 66º06.68’W) and the third site at 3989masl (24º18.24’S 66º08.44’W). The arthropods were collected seasonally using a pit-fall trapping from the spring 2005 until winter 2006. We put 10 traps on each sites and the activity of them was 7 days on each season. The collected material was identified in order, family and species/morphospecies using a digital dataset generated by TAXIS3.5 software. Eleven thousand four hundred and eighty nine arthropods were collected and the arachnids represented the 15% (1697 specimens). Acari was the most abundant (N01543, S=12) but Araneae was the more diverse (N=119, S=26) following by Solifugae (N=30, S=2) and Scorpiones (N=5, S=1). The index value cooresponding to each sites were: first site (S=26, N=532, D=0.2093, H’=2.077 and J’=0.6376); second site (S=33, N=1028, D=0.238, H’=1.984 and J’=0.5676), and third site (S=16, N=407, D=0.333, H’=1.528 and J’=0.5512). The first ante the second sites did not show a significant differences in S, D and H´. The first-third sites and the second-third sites showed significant differences between the index values. The cluster analysis showed more similarity between the first and the second sites (Jaccard index=0.595). Philodromidae was the dominant spider family in the first sites, Orsolobidae in the second and Dyctinidae in the third site. The Solifugae (Mummucidae) and the scorpions (Bothriuridae) were more abundant in the second site. The seasonal activity showed a great abundance of arachnid in summer. The second site is the more diverse maybe relationship with the vegetation heterogeneity and the texture and coverage of the soil.