Chronosequence of Natural Regeneration in Abandoned Mining Sites in the Amazon Rainforest of Madre De Dios, Peru

However, it has been facing severe deforestation and land degradation due to human activities such as gold mining, agriculture, logging, and cattle raising. Gold mining, in particular, has become a significant threat to the region's biodiversity, with an estimated 6145ha of forest cover lost annually. The region of Madre de Dios is located in the southeast of Peru, neighboring Bolivia and Brazil, and is divided into three provinces: Tambopata, Manu, and Tahuamanu. The area is rich in biodiversity, with 14 life zones identified, and has been suffering from the constant pressure of human activities. Gold mining has increased rapidly in the region, with small-scale mining operations being the primary source of income for local and outer residents. A study was conducted to analyze the chronosequence of natural regeneration in two active gold-mining sites in the region: Paolita and Santa Rita. The study aimed to investigate the response of forest after abandonment, focusing on the floristic composition and structure, and to analyze how remnant forest influences natural regeneration of nearby degraded lands. The study area was chosen based on two criteria: managed by the same individual or organization and early successional plots with a considerable distance to remnant forest. A total of 12 plots were established, with 6 plots at each site, measuring 20mx50m (0.1ha) each. The plots were randomly selected and named according to the mining site. Data analysis included the total number of individuals, recognized to the maximum level classification (species), and diameter at breast height (DBH) of all seedlings equal or greater than 1cm. Basal area of all species was computed, and diversity and similarity were measured using quantitative and qualitative indices. The results showed a variation of species and individuals along the successional stage gradient, with a dominance of some species. The number of individuals per plot and species composition was variable, with early successional stages having a higher quantity of pioneer species. The study found that seedlings in old stages of regeneration were small in number compared with early stages, confirming previous studies. The Shannon diversity index (H') and its respective evenness (E) were estimated, and Jaccard's similarity clustering was computed to analyze similarity between successional stages. The results showed that the abundance of species was higher in Paolita than in the Santa Rita mining site. The study also found that the nearby remnant forest might not have a great influence over natural regeneration in Paolita, whereas in Santa Rita, the similarity between remnant forest and successional stages was higher. The study's findings have significant implications for the conservation and management of the Amazon rainforest in Madre de Dios, Peru. The results highlight the importance of understanding the chronosequence of natural regeneration in abandoned mining sites and the influence of remnant forest on natural regeneration. The study's recommendations for conservation and management strategies include the establishment of protected areas, sustainable land-use planning, and the promotion of eco-tourism.