Climate influences on the radial growth of Centrolobium microchaete, a valuable timber species in the tropical dry forests of Bolivia

LIDIO LOPEZ, RICARDO VILLALBA Y MARIELOS PEÑA-CLAROS

Buenos Aires, Argentina

Congreso; Congreso Forestal Mundial; 2009

FAO

Expansion of the agricultural lands and the use of new technologies for forest harvesting are putting the remnant patches of Bolivian native forests at risk. It is imperative to establish management practices based on the precise rate of growth of the Bolivian Chiquitano forest to revert the current degradation processes associated with large-scale deforestation. In this study, we use tree-ring records to determine the rate of growth and the climate factors controlling the growth of Centrolobium microchaete, a high-valuable timber species in the tropical dry Chiquitano forest. We present the first tree-ring chronologies from C. microchaete in Concepción (16° 22´ S; 61° 68´ W) and Santa Mónica (15° 96´S; 62° 22´ W), and determine the relationships between variations in radial growth and climate during the 20th century. Statistical analyses show that the chronologies are of good quality and have a significant common signal between trees in each stand. The growth of C. microchaete is strongly influenced by climatic conditions during the summer, but important differences in tree responses to climate are recorded between stands, reflecting differences in climate and soil water capacity between sites. Although the chronologies only cover the past 180 years, adding samples from older individuals would permit the extension of these records further back time. The results from this study have important implications for the management of the Bolivian lowland forests, suggesting that rotation periods of 30 years, established by the Bolivian Forest Law, overestimate the rate of growth of the Chiquitano forest.