Forest structure of three endemic species of the genus Polylepis (Rosaceae) in central Perú

Polylepis (Rosaceae) is the dominant tree genus in High-Andean forest ecosystems. These ecosystems
are severely threatened, but li􀄴le is known about their structure and functioning. We provide the first reports
of the dasometric structure and spatial distribution of eight forests of Polylepis canoi, P. flavipila and P. rodolfovasquezii
in the Central Peruvian Andes as fundamental information for management and conservation
policies. We sampled all individuals ≥1 cm of diameter at ground level (DGL) in 20 plots of 10x10 m in each
forest, and measured total height (TH) and DGL. Also, we mapped the spatial distribution of the individuals
in two plots of 30x30 m (X and Y axes). We found differences in the dasometric structure between forests of
the same species, which, in some cases, were associated with climate, soil or elevation variables. However,
no well-defined pa􀄴ern was found. The allometric relationships of the linear and non-linear models did not
differ widely with respect to the R2 nor to the Akaike (AIC) scores, indicating that the forests did not show a
saturation of tree height with increasing diameter. In the P. canoi forests, individuals with diameters ≥10 cm
were the most abundant. In contrast, the forests of P. rodolfo-vasquezii showed a predominance of individuals
with diameters ≤10 cm, whereas P. flavipila presented an altered structure with no relationship between DGL
and TH in one of the evaluated forests. The analysis of spatial distribution according to the Ripley’s K function
on a small scale revealed that P. flavipila and P. canoi presented random pa􀄴erns, whereas P. rodolfo-vasquezii
showed an aggregate pa􀄴ern. Finally, our results showed that even forests of the same species have different
dasometric structures, whereas spatial pa􀄴erns differ only between species. So, caution must be taken when
extrapolating information between species or forests during ecological studies and conservation actions.