Abstract

CORREA-DIAZ, Arian et al. Dendroclimatic analysis of baldcypress (Taxodium mucronatum Ten.) in central Mexico. Agrociencia [online]. 2014, vol.48, n.5, pp.537-551. ISSN 2521-9766.

The historic information of growth rings in long-living trees and their relationship with climate is useful for understanding climatic variability and impact of man on the water cycle. The objective of the present study was to develop total ring dendrochronological series of Montezuma baldcypress (Taxodium mucronatum Ten.) in central Mexico to study their relationship with climate. The study sites were: San Felipe, State of Mexico (SF), San Miguel, state of Querétaro (SM), Tasquillo, state of Hidalgo (TA) and Jantetelco, state of Morelos (JA); located in different climatic conditions. The minimum and maximum amplitude of the chronologies were 109 for SF and 260 years for TA. Except for TA, all of the chronologies were highly significant. The highest variation among indices of ring width (RWI) was for SF (σ=2.66) and the lowest for JA ((σ=0.97). There was a significant correlation between RWI and basal area increment (BAI). BAI has remained stable in most of the sites, but in SF the BAI decreased by 85 % after 1970, although it had the youngest trees. No association was found among the dendrochronological indices of the sites studied, but in episodes of low frequency there was coincidence. In most of the sites, since 1910 the wet periods have been less frequent, going from a return period of approximately 15 to 40 years, whereas since 1970 the periods of extreme drought have gone from a return period of approximately 20 to 10 years. The growth of the Montezuma baldcypress presented minimum influence from the precipitation of previous years; however, for the growth year, the January-February precipitation was determinant for its development. The correlation among the climatic and growth variables varied among the sites; in SM precipitation was significant, but in SF temperature was more correlated with growth. For purposes of reconstruction and climatic projection, the growth rings of the Montezuma baldcypress of some sites are adequate for reconstructing the history of temperature, and for others rainfall.

Keywords : Baldcypress; juniper; ring chronologies; climatic variation.