Vegetation recovery on a gas-pipeline track along the elevational gradient of a subtropical montane forest

MALIZIA, A., NATACHA P CHACOFF, RICARDO GRAU, ALEJANDRO BROWN

Puerto Alegre, Brasil

Simposio; 45th Symposium of the International Association for Vegetation Science; 2002

International Association of Vegetation Science

Oil exploitation is an increasing activity in subtropical forests of NW Argentina that produces different ecological impacts. Understanding vegetation recovery after oil-related disturbances is essential for ecological impact assessments and restoration plans. However, basic information on these processes is lacking. The Nor-Andino gas pipeline stretches from NW Argentina to Northern Chile. In the Argentine portion it goes through the Yungas, from 450 to 2000m. We described patterns of re-vegetation on 15 sites distributed along the elevational gradient on this pipeline track, 12 months after the construction was finished. We measured saplings species richness and density and estimated vegetation cover and relative cover and richness of different life forms. Sapling species richness decreased with elevation. Cover recovery was 25% faster at 500 than at 2000m, and the recovery rate was linearly related to elevation. Species richness of trees and small shrubs decreased with elevation whereas herbs increased. Estimated cover of trees, small shrubs and grasses declined with altitude. Elevational gradients of forest recovery rates reflect expected differences due to the elevational decrease in temperature. Despite these differences, along the complete elevational gradient vegetation recovery implies relatively good capacity of these ecosystems for ecological restoration after this type of disturbance.