Tree rings indicate different drought resistance of two competing species in Sierra Tarahumara, México

POMPA-GARCIA, M; HADAD MARTÍN A.

Mendoza

Conferencia; Third American Dendrochronology Conference; 2016

CONICET

In northern Mexico, in the Sierra Tarahumara living diverse indigenous ethnic groups that are economically dependent on forestry. In this ecosystems grows Pinus durangensis and Pinus lumholtzi. These species are commercial interest and until the moment it has not been explored its dendrochronological potential. However the droughts could incite tree decline and death in Pinus spp. Forests. We study growth responses to drought using tree ring chronology of P. durangenisis and P. lumholtzi. Tree-ring width chronologies were related with Standardized Precipitation?Evapotranspiration Index (SPEI) to determine the significant times scale at which drought affected tree growth. The correlation coefficent showed that P. durangensis is more sensitive to drought. The tree growth was significant and negatively (r=-0.19 a -0.34, p=0.5) from January to October of prior growth period. P. lumholtzi showed more drought resistance, January and February were significant and negatively (r=-0.17 a -0.19, p=0.5) in prior growth period. Dry conditions before tree-ring formation affect the growth in P. durangensis and P. lumholtzi. In the context of climate change, Mexico has experienced an increase in temperature during the last century. If this trend continues and intensifies, can affect forest productivity and carbon cycles.