Age structure and climate sensitivity of a high Andean relict forest of Polylepis rodolfo-vasquezii in central Peru

Ginette Ticse-Otarola, Osir D Vidal, Laia Andreu-Hayles, Harold Rusbelth Quispe Melgar, Mariano M. Amoroso, Guaciara M. Santos, Edilson Jimmy Requena Rojas

Research output: Contribution to journalOriginal Articlepeer-review


For a better understanding of forest ecology, tree-ring studies can provide information on climate sensitivity, tree
growth patterns and population age structure that can inform about stand dynamics such as recruitment of new
individuals, and other interspecific interactions related to competition and facilitation. Little is known about the
ecology of the recently identified high Andean tree species Polylepis rodolfo-vasquezii. Here, we analyzed the
relationship between tree size and age of two P. rodolfo-vasquezii forest stands located in the central Peruvian
Andes at 11◦S in latitude, and compared their growth patterns and climate sensitivity. We measured the height
and diameter of each individual tree and collected tree core samples of living trees and cross sections of dead
standing trees to generate two centennial tree-ring chronology at Toldopampa (1825–2015 CE) and at Pomamanta
(1824–2014 CE) sites. The dendrochronological dates were evaluated by 14C analysis using the bombpulse
methods analyzing a total of 9 calendar years that confirm the annual periodicity of this tree species. At
the Toldopampa stand most trees ranged from 70 to 80 years old, with a 190-year old individual, being an older
and better preserve forest than Pomamanta, with younger trees, probably because more human disturbances due
to closer village proximity. No significant relationships were found between tree age and size in the oldest stand
alerting that tree diameter should not be used as a metric for estimating tree ages as a general rule. The distinct
growth patterns and the size-age relationship observed at the two forests may reflect distinct histories regarding
human activities such as fire and logging. Nevertheless, both the Toldopampa and the Pomamanta tree-ring
width chronologies exhibited common growth patterns and shared a similar positive response to temperature
of the current growing season. Overall, our study confirmed the annual radial growth periodicity in P. rodofolfovasquezii
trees using an independent method such as 14C analyses and a strong climate sensitivity of this tree
species. These findings encourage the development of an extensive P. rodolfo-vasquezii tree-ring network for
ecological and paleoclimate studies in the tropical Andes in South America.
Original languageAmerican English
Article number13
Pages (from-to)1
StatePublished - 10 Mar 2023

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