DENDROCHRONOLOGIC POTENTIAL OF Juniperus monticola MARTÍNEZ IN MOUNTAIN TLÁLOC, MÉXICO

Abstract

A 264-year chronological study (1750-2013) for total ring width was produced from 33 series of 50 specimens of Mexican juniper MJ, (Juniperus monticola Martínez), also known as enebro or cedro blanco, at Mount Tláloc, along an altitudinal range from 3980 to 4060 masl. Despite irregular transversal sections and ring-width variability of this species, COFECHA and ARSTAN dendrochronological parameters like mean sensitivity (0.41), series intercorrelation (0.51), and signal-to-noise ratio (1.24) indicated that for dendrochronological studies are viable on this species. The correlation of the ring width series to mean annual temperature was statistically significant (r = 0.45, n = 54, p < 0.01). Also, a significant correlation was found for other dated series in Pinus hartwegii from the Iztaccíhuatl and Pico de Orizaba volcanoes. Significant correlations were found between the SOI (r = -0.27, p < 0.01, n = 113) and PDSI indexes reconstructed for June in Central México (r = 0.25, p < 0.01, n = 109). These results indicate that climatological events could be reliably predicted from rings of MJ trees grown at high altitudes (> 3500 msnm). For this species, mean annual temperature correlated highest to ring width. Intense El Niño events associated to high radial growth. Given human influence on climate change and the ecological impact on high altitude species, MJ is a reliable species to understand climatic variability.