Arachnid assemblages in Tierra del Fuego landscape and impact in variable retention harvested forests.

MV LENCINAS; G MARTÍNEZ PASTUR; C GRISMADO

Tartu

Conferencia; IUFRO Landscape Ecology Conference; 2015

Tartu University

Spiders are relatively unknown in South Patagonia, but potentially useful as bio-indicators. Therefore, we evaluate potentiality analyzing spider assemblage at landscape level and impact under forest management in Tierra del Fuego. At landscape level we compare grasslands, peat-lands, Nothofagus antarctica and N. pumilio forests, while under management we study primary (BP) and harvested N. pumilio forests, with aggregated (RA) and dispersed (RD) retention. We located pitfall traps in 6 replica of each environment, which were collected every 15 days during one summer. We sampled 524 individuals from 41 species (Linyphiida, Mecysmaucheniida, Anyphaenida, Amaurobiida, Zodariida and Salticida families), with more abundant captures at the beginning of the summer. Richness and abundance followed the pattern: N. antarctica > N. pumilio > peat-land > grassland and RD > BP > RA, with 18 species characteristics of forests, 16 of open environments and 3 generalists. In harvested forests, 7 species diminished abundance, 11 were new or increased, and 5 did not varied. Ordination at landscape level showed differences among forests and open environments, while RA and RD overlapped distribution but RD had greater dispersion. Spider assemblage differed in landscape and under management, denoting to be a good potential bio-indicador of the environmental conservation status.