Conservation of land snails in the mountain grasslands of the Argeninian pampas

DELHEY VALDEMAR K.; BURELA SILVANA; PIZÁ JULIA; GHEZZI NATALIA S; CAZZANIGA NÉSTOR J.

Tentacle

IUCN/SSC Mollusc Specialist Group

Año: 2005 vol. 13 p. 11 - 13

0958-5079

 We performed a land snail and earthworm conservation project in this area, funded by the BP Conservation Programme 2002. Regarding land snails, the aim of our project was to investigate the distribution, habitat requirements and potentially threatening factors on land snail populations in the only reserve that protects this unique mountains: the ‘Ernesto Tornquist’ Provincial Park (ETPP). This reserve is cause of conservation concern due to the biological invasions of feral horses and exotic woody plants, especially pines, which could be also posing a threat to land snail populations. The qualitative type of response to environmetal variables was similar for the different snail species, and they commonly co-occurred. Snails preferred a balanced relative covers of rocks and vegetation. Plots without rocks were rejected, with a remarkable exception in summits, where we observed the highest densities of D. aguirrei (60 snails/10 m2) under the dense cover of stems of the endemic tiny shrub Grindelia ventanensis, in an area without rocks. We also observed the highest densities of P. patagonicus in summits (112 snails/ 10 m2), but in a plot with rocks and the shrub G. ventanensis. Resting sites differed among species. Austroborus lutescens dorbignyi is a burrowing species, never found attached to rocks. Narrow fissures among rock layers were used by V. avellanedae and D. aguirrei.