Distributional patterns of Geometridae of the Biobio Region, Chile: An approach for their conservation

The Biobio Region in south-central Chile is a climatic transition area where temperate and sclerophyllous forests co-occur, generating a high diversity zone. However, the area has been strongly affected by antropic intervention and only a few relicts of native forest and shrubland are left. Geometrid moths, like many other insects, are closely associated to the vegetation and therefore they will be directly affected by antropic intervention. Thus, in this study we assessed the patterns of distribution and diversity of geometrids in the Biobio Region, aiming to propose high-priority sites for conservation by identifying endemism areas and diversity hot spots. The available data were processed by parsimony analysis of endemism and complementarity analysis, helped by GIS, for to fill up records and to extrapolate the distribution of some species according to established criteria. We found a diversity of 120 geometrid species, corresponding to 37.5 % of the Chilean diversity, distributed in six endemism areas located in the most frequent vegetational formations in the Biobio region: the Nahuelbuta high-mountain forest, the sclerophyllous forest of sandy grounds, the deciduous forest of Concepcion, the Andean deciduous forest of the Biobio, and the deciduous forest of the frontier. Complementarity analysis revealed that there were 18 square plots which included the total number of species in the region. Based on the above analyses, we determined that five areas should be considered as high-priority sites for the conservation of geometrids: (1) the western slope of the Nahuelbuta mountain range and its adjacent coastal sector, (2) the Pencopolitan area of the coastal zone of the region, (3) Cerro Negro-Quillon, (4) Las Trancas, and (5) the Alto Biobio-Queuco valley zone.