FIRST TREE - RING CHRONOLOGY FROM CAESALPINIA ECHINATA LAM. (CAESALPINIOIDEA - LEGUMINIOSAE), AN ENDANGERED SPECIES FROM THE TROPICS IN BRAZIL.

TAHYSA MOTA MACEDO; CLAUDIA FRANCA BARROS; PIRAINO, SERGIO; CECÍLIA GONÇALVES COSTA; ROIG-JUÑENT, FIDEL ALEJANDRO

Salvador de Bahía

Congreso; XI Congreso Latinoamericano de Botanica; 2014

Caesalpinia echinata Lam. is a native tree species that named Brazil and occur from Rio Grande do Norte (5º11´56´´ S - 35º27´39´´W) to Rio de Janeiro 22º54´ 10´´S - 43º12´27´´W) in the Atlantic Rain forest at the coastal zone of Brazil. The species known as Brazilwood was used up to XIX century to produce dyes and afterward for the manufacture of high quality bows for stringed instruments. Because its history of wood exploitation and its localization in densely populated urban areas of Brazil, the species is included as endangered on the CITES and IUCN red list. However, little is known about its growth and the possible influence of climatic parameters in the growth of native populations, which could be an important data for species conservation. We present the first tree-ring chronology of Brazilwood from Armação de Búzios, Rio de Janeiro. We used this tree-ring record to examine the climate factors controlling the growth of C. echinata. Thus, two-four rays from 14 trees were dated, measured and dating quality controlled by cross-matching techniques, to finally construct a tree-ring index chronology based on the growth information from 9 trees. Correlation analyses were performed between the chronology and monthly precipitation and total precipitation. Growth ring boundaries are evident by a marginal parenchyma, with combinations of locally distended rays, latewood thicker and radially flattened fiber walls and differences in the vessel diameter between contiguous rings. The cross-dating indicated an intercorrelation between tree-ring series of 0.41, and a mean sensitivity of 0.71. Correlation analysis between the individual species chronologies and monthly precipitation revealed significant correlations during the late-spring and early summer, r= 0.26, confirming a strong influence of the precipitation during the late spring (September)-early summer (March) on C. echinata radial growth during the interval 1953-2012. The present study revealed that precipitation is the main factor determining growth variability of C. echinata in the Atlantic Rain forest, and represent important advance for future studies in different populations