Tropical foothill forests are heterogeneous transition zones, yet field inventories remain sparse in the Andean–Amazonian region. We compared four forest stands to establish a local biodiversity baseline and determine whether tree diversity, floristic differentiation, and stand structure showed similar descriptive patterns. Four 0.25-ha plots located between 239 and 487 m a.s.l. in Madre de Dios, Peru, were inventoried for trees with diameter at breast height ≥ 10 cm. Diversity was characterized using Hill numbers, floristic differentiation using coverage-standardized beta diversity, and forest structure and soil properties descriptively. We recorded 532 trees representing 163 species, 97 genera, and 34 families. Observed richness ranged from 56 to 68 species, whereas abundance-weighted diversity varied more markedly. At 84% sample coverage, richness-based Sørensen-type and Jaccard-type dissimilarities ranged from 0.251 to 0.602 and from 0.401 to 0.752, respectively. Structural attributes varied among plots but did not follow the same ordering as diversity or floristic differentiation. Soil properties were treated solely as environmental context because each plot had one composite sample. The findings document heterogeneity among the four sampled stands and provide a sampling-standardized baseline for this poorly documented foothill sector, without establishing regional patterns or environmental causes.

Gold mining alters tropical forests, but its association with medicinal tree assemblages remains poorly documented in the Peruvian Amazon. We compared taxonomic diversity, floristic composition, and forest structure between three gold-mining-disturbed plots and their corresponding reference forests in San Juan, Huacamayo-Pacal, and Boca Amigo, Manu Province. Six permanent 1 ha plots contained 1878 non-palm medicinal trees representing 182 species and 46 families. Diversity was assessed using Hill numbers, rarefaction and extrapolation, sample coverage, beta diversity, NMDS, PERMANOVA, and structural attributes. Species richness and effective diversity were consistently lower in disturbed plots. Relative to their paired reference forests, species richness was lower by 52.3%, 18.5%, and 22.5%; q = 1 diversity was lower by 69.3%, 35.7%, and 25.2%, and q = 2 diversity was lower by 77.5%, 59.6%, and 26.6%. Basal area was also lower by 43.0%, 33.2%, and 31.2%, respectively. Floristic differentiation was strongest in San Juan, while multivariate composition differed among the six sampled plots (PERMANOVA: pseudo-F = 4.156, R² = 0.278). These results show consistent differences in medicinal tree diversity between disturbed and reference plots, although the magnitude of floristic and structural contrasts varied among communities.

High-Andean environments impose severe limitations on tree establishment, making early survival and growth decisive for restoration success. This study evaluated differences associated with four island-guano doses—0, 150, 300, and 450 g plant⁻¹—applied in separate treatment strips to Polylepis racemosa established in a grassland at 4239 m a.s.l. A monitored cohort of 148 plants, with 37 individuals per treatment strip, was assessed at establishment and after 4, 8, and 12 months. Survival, interval mortality, total height, basal diameter, cumulative increments, and relative growth rates were analyzed using longitudinal mixed models. All plants survived during the first four months, but survival declined afterward. At 12 months, survival reached 29.7% in the control strip and 45.9%, 43.2%, and 37.8% in the strips receiving 150, 300, and 450 g plant⁻¹, respectively. The strongest height and basal-diameter responses occurred in the 300 and 450 g plant⁻¹ strips. The highest-dose strip showed the greatest final height, basal diameter, and cumulative growth increments, whereas the highest relative growth rates under the larger doses occurred mainly during the first four months. The 150 g plant⁻¹ strip showed slower structural development but the highest final survival. These results indicate a non-linear pattern associated with island-guano dose, as the strip showing the greatest growth did not show the highest persistence. Considering final survival together with structural growth, the 300 g plant⁻¹ strip showed the most balanced pattern within the evaluated plantation. This interpretation does not identify a generally optimal dose, and replicated, longer-term trials are required before broader recommendations can be made.

Alluvial gold mining can alter Amazonian tree communities, but its association with medicinal tree diversity, structure, and carbon stocks remains poorly documented. We compared four 1-ha forest plots in Boca Colorado, Madre de Dios, Peru: two with greater evidence of mining intervention and two less-impacted plots. All medicinal trees with DBH ≥ 10 cm were inventoried, and taxon richness, Hill diversity, rarefaction, floristic dissimilarity, dominance, structural attributes, and biomass carbon were evaluated. A total of 1344 individuals representing 203 taxa were recorded. Mean plot-level richness was higher in less-impacted forests than in impacted forests (135.5 vs. 95.5 taxa), as were diversity of orders q = 1 (79.9 vs. 48.1) and q = 2 (38.7 vs. 23.6). Richness therefore showed a scale-dependent pattern: less-impacted plots were richer individually, whereas impacted forests accumulated more taxa when plots were pooled (172 vs. 143), reflecting greater among-plot differentiation. Turnover accounted for 79.5% of Jaccard dissimilarity. Less-impacted forests also had 16.1% higher stem density and 47.1% higher total biomass carbon, with the carbon contrast supported by the hierarchical bootstrap analysis (p = 0.043). These findings indicate that mining intervention was associated with differences in abundance distribution, floristic composition, forest structure, and carbon stocks that were not captured by pooled richness alone.

Agroindustrial lignocellulosic residues represent potential secondary resources, but their response to a common fractionation process can vary substantially with feedstock composition. This study evaluated organosolv processing of coconut fiber, maize cob, coffee parchment, and cocoa parchment under identical ethanol–acetic acid conditions. Untreated and processed solids were compared for physicochemical and compositional properties, and residue-specific responses were integrated using fiber enrichment, organic-solids equivalents, and non-dominance screening. Organosolv processing increased mean crude-fiber content from 25.04% to 66.74% and pH from 5.70 to 6.35; both effects remained significant after Holm correction. COD decreased in all residues, although the treatment-level response was not significant after multiplicity adjustment. Fiber enrichment occurred in every feedstock but varied markedly, with coffee parchment showing the largest proportional increase. Material-use profiles also differed: coconut fiber reached the highest crude-fiber concentration, whereas coffee parchment combined high fiber enrichment with the highest organic-solids equivalent and lowest ash content. Coconut fiber, maize cob, and coffee parchment were non-dominated under the exploratory screening. These results show that organosolv processing can produce fiber-enriched solids from contrasting agroindustrial residues, while the broader compositional outcome remains feedstock-dependent.