Tree-ring chronology network from Centrolobium microchaete in the tropical Cerrado region, Santa Cruz, Bolivia

LIDIO LOPEZ; RICARDO VILLALBA

Melbourne

Congreso; WorldDendro Conference 2014; 2014

The Cerrado, one of the largest biogeographical regions in South America (> 24 million ha), extends from central Brazil to eastern Bolivia and northeastern Paraguay. In Bolivia, the Cerrado region covers an area > 16.5 million ha and includes both wet and dry tropical ecosystems. In order to reconstruct past regional climatic variations, cross-sections of Centrolobium microchaete were collected from sites with current logging located in both wet and dry forests. Eight site chronologies have been developed by measuring ring widths from previously dated cross-sections. The number of trees per site chronology varies from 22 in Zapocó to more than 50 in Santa Monica. Tree-ring chronologies from humid sites are shorter in length (Makanaté, 100 years) than those originating from trees in dry forests (Purubí, 254 years). The statistics indicate that the chronologies are of good quality with a high percentage of common signals between trees. The growth of C. microchaete is strongly influenced by weather conditions during summer. Summer rainfalls favor radial growth, whereas high summer temperatures, which reduce the water available for growth, are inversely correlated to tree growth. This newly developed chronology network will be used to develop the first dendroclimatic reconstructions in the Bolivian Cerrado region.