Identification and characterization of Prosopis sp growth rings in Peru northern coast

Abstract

Prosopis sp. is an emblematic genre on Peru coast; our ancestors have used it as a base in archaeological temples and colonial churches. Several dendropaleoclimatic studies have demonstrated that these species can be used as a source for the reconstruction of climatic events, for it is crucial identification and characterization of its growth rings since these species presents / displays variations in the wood growth with formation of false rings and missing rings. This research identifies and characterizes the growth rings of the specie Prosopis sp. and a methodology is presented in order to improve the dendrochronological series. False and absent rings formation can generate individual growth series which, when overlapped, have a low correlation (r = 0,2). Using CDendro software, correlations are improved by the insertion or elimination of growth rings in two ways: 1) dendrochronological series correlation of same disc radii for the errors detection in growth; 2) dendrochronological series correlation of different individuals using “El Niño” events as axes for sequence overlap. The corrected growth series gave better mean values of correlation coefficients, chi-square and test of 0,5; 4,8; 3,9 respectively. At the same time, maximum values were 0,65; 12,5; 5,5 respectively. In this way we can prove that the dendrochronological reading of Prosopis sp. Series can improve through a morphological and climatic growth study.