Polylepis woodlands, endemic to the Andean Mountains, are critical for biodiversity and ecosystem services but face threats from anthropogenic disturbances and climate change. This study employed sonic tomography (ST) to assess the structural integrity of three relict Polylepis stands on the western slopes of the Peruvian Andes. A total of 192 tomograms from 48 trees across three sites revealed substantial variation in internal decay (2.5–70%), with mean decay levels of 11.6% (Z1), 16.6% (Z2), and 10.5% (Z3). Although the initial generalized linear mixed models (GLMMs) suggested tree diameters at breast height (DBH) as a potential predictor of decay, subsequent non-parametric Spearman’s correlation analysis found no significant relationship between DBH and decay (r < 0.001, p > 0.05) or between altitude and decay (r = 0.187, p = 0.204). No significant differences were detected among species or zones. The study demonstrates the efficacy of ST for noninvasive health assessment in high-altitude ecosystems and underscores the need for long-term monitoring to guide conservation strategies.

This study assessed the floristic composition, endemism, and conservation status of three relict Polylepis forests (“queñua”) in Oyón, Peru, located between 4000 and 4500 m a.s.l. A total of 150 vascular plant species were recorded, belonging to 100 genera and 47 families. Asteraceae (52 spp.) and Poaceae (17 spp.) were the most diverse, while herbs dominated the life-form spectrum (73%). Species richness decreased significantly with elevation (R² = 0.86, p < 0.001): Zone 3 (4000 m) hosted 100 species, Zone 2 had 52, and Zone 1 had 35. Floristic similarity (Jaccard index) revealed that Zone 3 was the most distinct, sharing as little as 6% of its species with higher zones. Endemism was notable, with 14 species (9.33%), 100% concentrated in Zone 3, which also harbored 71.4% of the 7 species categorized as threatened, including Polylepis incana (CR) and Senecio nutans (VU). These findings identify lower-elevation relicts as critical biodiversity hotspots, likely sustained by milder microclimates and greater habitat heterogeneity. However, ongoing threats from fragmentation, logging, and grazing jeopardize their persistence. Therefore, site-specific conservation strategies that prioritize these lower-altitude hotspots are urgently required.

Palms of the genus Ceroxylon constitute a key component of Andean tropical montane forests; however, their internal structural integrity has been scarcely studied in Peru. The present study assessed the internal structural condition of natural populations within the Private Conservation Area (PCA) Bosque de Palmeras of the Taulía-Molinopampa Peasant Community using sonic tomography, a non-invasive technique for detecting cavities and decay in the stipe. A total of 64 individuals distributed across four zones with differing degrees of anthropogenic disturbance — passive recovery, reforestation, active cattle ranching, and mixed forest — were analyzed, generating 256 tomograms at four vertical levels. Results revealed high levels of structural deterioration across all zones (59.8%–67.9%), with the greatest affectation recorded in the active cattle ranching zone, and significant differences among zones (Kruskal–Wallis, p < 0.05). A significant positive correlation was found between diameter at breast height (DBH) and structural damage (ρ = 0.298; p = 0.0168), whereas altitude showed no significant association (p = 0.7462). Structural deterioration exhibited a heterogeneous distribution both vertically and among individuals. Taken together, these findings indicate that anthropogenic activities increase structural deterioration and compromise the stability of Ceroxylon populations, and confirm the potential of sonic tomography as an effective tool for the monitoring and conservation of Andean palms.

Palms of the genus Ceroxylon constitute a key component of Andean tropical montane forests; however, their internal structural integrity has been scarcely studied in Peru. The present study assessed the internal structural condition of natural populations within the Private Conservation Area (PCA) Bosque de Palmeras of the Taulía-Molinopampa (Amazonas, Peru) using sonic tomography. A total of 64 individuals distributed across four zones with differing degrees of anthropogenic disturbance—Mixed Forest (MF), Active Restoration (AR), Passive Restoration (PR), and Cattle Ranching (CR)—were analyzed, generating 256 tomograms across four vertical levels. Results revealed high levels of structural deterioration (mean = 63.58%), with significant differences observed among zones (p < 0.05). A linear mixed model (LMM) demonstrated that both study zone and diameter at breast height (DBH) are significant predictors of decay (p < 0.05), with the CR zone exhibiting a significant increase of 9.28% in damage compared to the MF reference. Furthermore, a significant positive relationship was found between DBH and structural damage (increase of 0.419% per cm), while fixed effects in the model explained 24.1% of the total variance. Structural deterioration exhibited a heterogeneous vertical distribution, being most sensitive to anthropogenic pressure at the basal level (10 cm). These findings demonstrate that areas under greater anthropogenic pressure and larger individuals are associated with higher structural deterioration, confirming the potential of sonic tomography as an effective tool for the monitoring and conservation of Andean palms.

Tropical Amazonian forests serve as critical carbon reservoirs, although their storage capacity varies significantly depending on the topographic, hydrologic, and successional heterogeneity of the landscape. This study quantified aboveground biomass (AGB) and carbon stocks across four vegetation units in the Tacshitea sector, Sierra del Divisor Na-tional Park (Peru): semi-dense flooded forest (Z1), hill forest (Z2), hill forest associated with secondary growth (Z3), and Mauritia flexuosa palm forest (Z4). We established 100 plots of 20 × 20 m (1 ha per zone), assessing all individuals with diameter at breast height (DBH) ≥ 10 cm using allometric equations validated for Amazonian ecosystems. A total of 2,363 individuals belonging to 158 species from 41 families were recorded. AGB varied sig-nificantly among vegetation units (Kruskal-Wallis, p < 0.001), with the highest values in Z1 (414.09 Mg ha⁻¹; 194.62 Mg C ha⁻¹) and Z2 (332.01 Mg ha⁻¹; 156.05 Mg C ha⁻¹), whereas Z3 and Z4 recorded substantially lower values (145.27–153.18 Mg ha⁻¹; 68.28–71.99 Mg C ha⁻¹). The Fabaceae family dominated carbon storage at the landscape scale (33.82%). Floristic diversity showed positive but weak associations with carbon storage (R² = 0.045–0.056), and this relationship lost significance when controlling for spatial structure using linear mixed-effects models (p = 0.409), indicating that structural attributes—particularly basal area and wood density—are more robust predictors of storage capacity than taxo-nomic richness per se. Beta diversity analysis revealed that floristic differentiation among zones was dominated by species turnover, explaining 26.5% of the variation by vege-tation unit (PERMANOVA, F = 11.55; p = 0.001). These results support the relevance of Sierra del Divisor National Park as a priority carbon sink in the western Peruvian Amazon and underscore the necessity of conservation strategies that integrate the structural heterogeneity of the forest mosaic.

Amazonian forests store large amounts of carbon, but storage capacity varies widely with topography, hydrology and successional stage. We quantified aboveground biomass (AGB) and carbon stocks across four vegetation units in the Tacshitea sector, Sierra del Divisor National Park (Peru): semi-dense flooded forest (Z1), hill forest (Z2), hill forest associated with secondary growth (Z3), and Mauritia flexuosa palm forest (Z4). In each unit we established a contiguous 5 × 5 grid of 20 × 20 m plots (25 plots, 1 ha sampled per unit) and assessed all individuals with diameter at breast height (DBH) ≥ 10 cm, using allometric equations validated for Amazonian ecosystems. A total of 2363 individuals belonging to 156 species from 41 families were recorded. Aboveground biomass differed markedly among vegetation units, with the highest values in Z1 (401.15 Mg ha⁻¹; 188.54 Mg C ha⁻¹) and Z2 (328.92 Mg ha⁻¹; 154.59 Mg C ha⁻¹), whereas Z3 and Z4 recorded substantially lower values (142.25–144.53 Mg ha⁻¹; 66.86–67.93 Mg C ha⁻¹). The Fabaceae family dominated carbon storage at the landscape scale (34.7%). Comparing predictor blocks directly at the plot level, structural attributes explained 92.4% of the variance in carbon stock against 5.6% for taxonomic diversity (ΔAIC = 248), and variance partitioning attributed 87.3% exclusively to structure and 0.5% exclusively to diversity, indicating that basal area, wood density and stem size are far more robust predictors of storage capacity than taxonomic richness per se. Beta diversity analysis revealed that floristic differentiation among zones was dominated by species turnover, explaining 26.5% of the variation by vegetation unit (PERMANOVA, F = 11.54; p = 0.001), although within-unit dispersion was heterogeneous, so part of that signal reflects differences in internal variability rather than centroid position alone. Because each unit was sampled as a single contiguous block, unit effects are confounded with location, and the comparisons describe the four stands evaluated at Tacshitea rather than the vegetation types they represent. These results support the relevance of Sierra del Divisor National Park as a carbon reservoir in the western Peruvian Amazon and underscore the necessity of conservation strategies that integrate the structural heterogeneity of the forest mosaic.