1 Subalpine Nothofagus and Araucaria forests across an environmental and disturbance gradient in South Central Chile: a floristic approach

• Main Authors: Eduardo A, B. Paul
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Araucaria raucana; Chile; environmental gradient; volcanism; disturbance; subalpine Abbreviations; Antarc*; Antarctica
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.561.8280; http://www2.udec.cl/~pauchard/conguillio.pdf

Vegetation response to environment and disturbance were studied in a subalpine volcanic national park in southern Chile to better understand how this unique flora responds to complex gradients, and to provide baseline information for environmental assessment studies in the region. We describe community assemblages and species distribution patterns in a Nothofagus pp.- Araucaria araucana forest mosaic using physiognomic vegetation mapping, phytosociological classification methods and an indirect gradient analysis. Four physiognomic types were defined including 3 forest types and a lake shore shrubland. Six plant communities were defined (4 forest, 1 shrubland and 1 grassland). Most of the study area was dominated by a mixed Nothofagus antarctica – A. araucana forest followed by N. dombeyi – A. araucana forests. A. araucana had multimodal diameter distributions reflecting a long history of fire and volcanic disturbances. Detrended correspondance analysis suggested that floristic patterns followed a disturbance and geomorphic gradient. Temperature extremes and disturbance types were hypothesized as the most critical factors determining changes in dominant species distributions. The gradient was closely correlated with vegetation structural complexity. We found 115 species belonging to 45 families in the 241 ha study area. The highest diversity occurred in pure N. antarctica forests, intermediate in total cover and height.