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

LENCINAS, MV; MARTÍNEZ PASTUR, G; SOLER, R; SCHINDLER, S; CELLINI, JM; KREPS, G; HENN, J; IVANCICH, H; FRANCO, G; PERI, P; ANDERSON, CB; BARRERA, M; PAULI, H

Bergün

Conferencia; Conference Faster, Higher, More? Past, present and future dynamics of alpine and Arctic flora under climate change.; 2013

GLORIA

Plant diversity in sub-Antarctic ecosystems is currently threatened by land use, forest management, cattle grazing, species invasion and climate change. At a regional scale, large areas are preserved as protected areas, but their effectiveness for biodiversity conservation is unknown, untested or doubtful. Recently, national legislation has promoted native forest conservation in both Argentina and Chile, but biodiversity values were not explicitly applied as selection criteria, and protected areas were mostly assigned to marginal unproductive forests. Additionally, climate change could shift species? ranges to higher altitudes, but distributions of sensitive plant species remain unknown for the southern Andean region. Based on 535 floristic inventories (richness, coverage), including 230 vascular plant species distributed throughout Tierra del Fuego, we assessed plant distribution at stand, landscape and regional scales. We developed habitat suitability maps for 35 vascular plants using environmental niche factor analysis (ENFA) and a set of 14 environmental predictor variables. Maps were combined into an overall plant diversity conservation map, which showed the low effectiveness of the actual protected areas. We proposed this method as a decision tool for conservation strategies at the regional level. Additionally, a GLORIA-target region was established and sampled in Tierra del Fuego (54º39´50"S, 67º46´26"W, on the northern slopes of the Andean mountain range) during 2012-2013, to start a long term study about the impact of climate change in the upper tree-line ecosystems. The four summits were established between tree-line and higher elevations, where conditions limited most of the vascular vegetation. Thirty four species of vascular plants were detected with a clear decrease from the lowest peak (643masl-30 species) to the highest peak (867masl-11 species). Richness and coverage did not differ significantly among orientations (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 where the lower elevation level contained higher richness (F=15.0, p=0.008) and cover (F=26.7, p=0.002). ENFA models under different climate change scenarios could allow the identification of areas that should be conserved for hosting future conditions suitable for relevant plant species. Appropriate management actions including a targeted network of protected areas should be established for conserving plant diversity.