Desert soil fauna is more vulnerable to pine afforestation than in old-growth natural forests

ADELIA GONZÁLEZ ARZAC; AMY T. AUSTIN

Capital Federal

Simposio; 32nd New Phytologist Symposium: Plant interactions with other organisms:molecules, ecology and evolution; 2013

New Phytologist Trust

Soil fauna are a fundamental component of terrestrial ecosystems, in part due to their importance in the decomposition of organic matter, and carbon and nutrient cycling in terrestrial ecosystems. Exotic conifer afforestation is becoming increasingly popular as a mitigation measure to compensate for increased CO2 emissions from human activity, but the effects of these land-use changes on soil fauna are relatively unknown The objective of this study was to evaluate the effects of pine afforestation on soil fauna communities along a precipitation gradient (250-2200 mm MAP) in Patagonia, Argentina, comparing native intact vegetation with afforested plantations of similar age. The effects of afforestation in arid zones were dramatic for soil macrofaunal invertebrates, including the disappearance of a key predator, significant reduction in ant abundance, and the appearance of novel fungivorous groups. Overall, there was a marked homogenization in the soil communities along the precipitation gradient in pine plantations, and all afforested sites were more similar to the natural forests than to the steppes or woodlands they were replacing. Caution should be employed when considering afforestation projects due to potential for multiple collateral effects on the natural biodiversity in terrestrial ecosystems, and the inherent vulnerability to disturbance of soil faunal communities.