Plant conservation in Tierra del Fuego: assessing assemblages across scales, modeling habitat suitability, and analyzing GLORIA baseline data

LENCINAS, MARIA VANESSA; MARTÍNEZ PASTUR, GUILLERMO; SOLER ESTEBAN, ROSINA MATILDE; SCHINDLER, STEFAN; JUAN MANUEL CELLINI; KREPS, GASTÓN; HENN, JONATHAN JEFFREY; IVANCICH, HORACIO; PERI, PABLO LUIS; ANDERSON, CHRISTOPHER; BARRERA, MARCELO; PAULI, HARALD

Bergün

Simposio; Faster, Higher, More?; 2013

Plant conservation in Sub-antarctic ecosystems is currently threatened by land management, fragmentation, species invasion and climate change. At a regional scale, large areas are preserved as natural reserves, but their effectiveness in plant conservation is usually unknown. Recently, national legislations promote native forest conservation in Argentina and Chile, but biodiversity values are not explicitly included in forest evaluation, regarding most of the protection to marginal unproductive forests. Moreover, it is expected a shift in species? ranges to higher altitudes mainly due to climate warming, but sensitive plant species distribution in South Andes region remains unknown. Therefore, we present here evidences about differences in plant species distribution within regional, local and stand scales, which reduce effectiveness of large natural reserves as a conservation strategy, based in 535 floristic inventories (richness and cover) including 230 vascular plant species, distributed throughout Tierra del Fuego. Likewise, we develop biodiversity conservation maps using environmental niche factor analysis (ENFA) for 35 vascular plants, based on climatic and topographical predictor variables, and combined it in a unique plant diversity conservation map, which is proposed as a decision tool for conservation strategies at regional level. Finally, a GLORIA-target region was established and sampled in Tierra del Fuego during 2012 and 2013, to start a long term study about the impact of climate change in alpine ecosystems. It is located East of Lago Escondido (54º39'50"S, 67º46'26"W) on the northern slopes of the Andean main chain. Conditions are suitable for alpine vegetation in a narrow fringe between the tree line and the inhostile higher elevations, and the four summits were established in elevations between 643 - 867 m. 34 species of vascular plants were detected with a clear decline from the lowest peak (30 species) to the highest peak (11 species). Species richness and coverage did not differ significantly among orientations (N, E, S, W; F=5.1, p=0.07) or elevation levels (0-5m vs. 5-10m below summit; F=1.7, p=0.24), except for the highest peak were the lower elevation level had more plants (richness: F=15.0, p=0.008; coverage: F=26.7, p=0.002). Landscape analysis and ENFA simulations under different climate change scenarios could allow us to identify areas with better status of the original vegetation diversity (composition and structure) to be conserved, by applying appropriate management actions for important and sensitive species.