Few studies describe the factors that influence the natural regeneration in abandoned gold mining areas in the Amazon. Here we focus on the influence of the distance to the forest edge and abandonment time in a spontaneous succession of degraded areas by gold mining in the southeastern Peruvian Amazon. We assessed woody species composition (DBH ≥ 1 cm) and forest stand structure across a chronosequence (2–23 years). A total of 79 species belonging to 30 families were identified. The natural regeneration was dominated by Fabaceae, Malvaceae, and Urticaceae. Together, they represented 60% of the importance index. Cecropia membranacea and Ochroma pyramidale were the dominant pioneer species at the initial successional stage. The basal area and species diversity were directly related to time after abandonment and inversely related to the distance to forest edges. The distance-based redundancy analysis showed that more of the variation in species composition was explained by distance to the forest edge than the abandonment time. Our study revealed that regeneration was relatively slow and provided evidence that the distance to the forest edge is important for natural regeneration in areas degraded by gold mining.

Amazon rainforests are critical for providing a wide range of ecosystem services. In the Southeastern Peruvian Amazon; however, goldmining activities are causing severe soil degradation and forest loss. We analyzed aboveground biomass (AGB), forest structure, and species diversity recovery during secondary succession in 179 forest plots. Our study provides the first field-based quantification of AGB recovery following the abandonment by two types of goldmining (heavy machinery and suction pumping) in Madre de Dios (Peru). We found that successional secondary forests in areas subjected to suction pumping were more resilient than those in areas subjected to heavy machinery. After 20 years, mean AGB in suction pumping mining areas had reached 56% of reference forest AGB, while in areas of heavy machinery mining it was only 18%. Mining type, stand age, and distance from the forest edge had a significant effect on AGB. The influence of the distance from the forest edge on AGB varies according to mining type because the effects of species diversity on AGB are mediated by the distance from the forest edge. Our results clearly showed the dynamics of AGB recovery across a secondary succession after goldmining, and the contrasting responses of AGB between the two mining types. Our study disentangles the importance of key factors in forest recovery after mining and improves understanding of the resilience of biomass accumulation in these highly degraded ecosystems.

El sur peruano es un centro de alta biodiversidad, aunque algunas áreas están poco investigadas y vienen siendo diezmados por actividades antrópicas. Este estudio evaluó la composición, estructura, diversidad y biomasa arbórea del bosque Amazónico del Castañal – IIAP, en la región de Madre de Dios. Mediante una parcela de una hectárea evaluaron la composición, la distribución de alturas y diámetros (DAP) y el Índice de Valor de Importancia. La biomasa arbórea se estimó con ecuaciones alométricas de Chave. Se evaluaron 464 individuos, de 197 especies, 125 géneros y 46 familias botánicas; la diversidad Alfa de Fisher fue de 129. Las familias más diversas fueron Fabaceae, Moraceae, Malvaceae. Los géneros más diversos fueron Inga, Licania, Naucleopsis, Neea y Ocotea con cinco especies cada una. Las especies con mayor Índice de Valor de Importancia (IVI) fueron Euterpe precatoria (8.48), seguida por Leonia glicycarpa (8.29) y Iryanthera laevis (8.06). La Biomasa alcanzó 283,56 toneladas/hectárea, destacando Handroanthus serratifolius con 35.028 (t/ha), representando el 12.13% del total y Bertholletia excelsa con 25.146 (t/ha). Estos resultados son clave para la planificación de estrategias de conservación y manejo forestal en la región de Madre de Dios.

Las comunidades nativas en la Amazonía históricamente han hecho uso y manejo de las plantas beneficio de diferentes necesidades. El objetivo del estudio fue registrar, caracterizar y documentar los conocimientos etnobotánicos tradicionales en las comunidades nativas de Sonene y Palma Real, en la Amazonía de Madre de Dios, Perú. En la comunidad nativa (C.N.) de Sonene se encontró un mayor número de especies con un uso tradicional que en la C.N. de Palma real, 103 y 92 respectivamente. Las familias dominantes fueron Fabaceae y Araceae. Las categorías de uso más representativos en ambas comunidades fueron: Medicinal en Palma Real (50%) y Sonene (68%)., las otras categorías han sido: para Palma Real Alimenticio (16%), Construcción (12%), Cultural y Colorante con 5% cada una; para Sonene Alimenticio (14%), Construcción (9%), y artesanal con 4%. Las especies con poseen mayores categorías de uso fueron: Bertholletia excelsa (Med, Ali, Con), Genipa americana (Ali, Cons, Col), Iriartea deltoidea (Med, Ali, Con) y Psidium guajava (Med, Ali, Art). La especie de con mayor frecuencia de mención por los pobladores fue: P. guajava. A nivel de especie son frecuentes de uso en ambas comunidades 13 especies, siendo: Paullinia bracteosa, Sapium marmieri, Piper aduncum, Banisteriopsis caapi, Uncaria guianensis, Ficus insipida y Abuta grandifolia. El órgano de las plantas más utilizadas en las comunidades fue las hojas (>35% de las especies), seguido por tallos y frutos. Este estudio nos ha permitido confirmar que existe un gran conocimiento de las plantas útiles en las dos comunidades nativas, pero a pesar que aún se conservan muchos de ellos, las generaciones actuales muestran un cierto desinterés en el aprendizaje y aplicación de estos conocimientos provistos por padres y abuelos.

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.

Reportamos por primera vez para Perú el árbol Piptocarpha rotundifolia (Less.) Baker (Asteraceae), esta proviene de las Sabanas húmedas de Pampas del Heath, ubicada en el Parque Nacional Bahuaja Sonene, en la Amazonía sur peruana. Se proporciona una descripción actualizada de P. rotundifolia y fotografías detalladas.