Dendroclimatological assessment of Polylepis rodolfo-vasquezii: A novel Polylepis species in the Peru highlands

REQUENA-ROJAS, E.J.; VILLALBA, R.; MORALES, M.

Dendrochronologia

ELSEVIER GMBH, URBAN & FISCHER VERLAG

Lugar: ALEMANIA; Año: 2020 vol. 62

1125-7865

In spite of enormous diversity in tree species, dendrochronological records in the tropical Andes are very scarce.Therefore, it is necessary to increase the search for new tree species with high dendrochronological characteristicsin the tropical Andes, including the humid Puna of Peru. We present the first tree-ring chronology fromPolylepis rodolfo-vasquezii, a recently described tree species in the Central Andes of Peru between 4000 and 4400m elevation. Fifty trees were sampled in the district of Comas, Peru. After establishing the anatomical characteristicsthat delimit the annual growth rings, we developed a ring-width chronology by applying conventionaldendrochronological techniques. The chronology covers the period 1869?2015 (157 years) and is well replicatedfrom 1920 to present (> 20 samples). The statistics used to evaluate the quality of the chronology indicate thatthe P. rodolfo-vasquezii has similar values of MS, RBAR and EPS to those shown by other Polylepis spp chronologies.To determine the main climatic factors controlling the growth of P. rodolfo-vasquezii, we compared ourchronology with local and regional temperature and precipitation records. Growth season temperature(November to May) seems to be the main climatic factor modulating inter-annual variations in the growth of thisspecies. The sensitivity to inter-annual temperature variations highlights the potential of P. rodolfo-vasquezii toprovide climatically sensitive dendrochronological records in the Central Andes. To our knowledge, this is thefirst tree-ring record in South America displaying significant relationships with temperature over the tropicalAtlantic Ocean.