Changes in floristic and vegetation structure in a chronosequence of abandoned gold-mining lands in a tropical Amazon forest

• Published in: Heliyon Vol. 10; no. 9; p. e29908
• Main Authors: Garate-Quispe, Jorge, Canahuire-Robles, Ramiro, Alarcón-Aguirre, Gabriel, Dueñas-Linares, Hugo, Roman-Dañobeytia, Francisco
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15-05-2024; Elsevier
• Subjects: ASGM; Madre de dios; Natural regeneration; Reference forests; Secondary succession; Madre de dios; Secondary succession; ASGM; Natural regeneration; Reference forests
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2024.e29908

This study analyzes floristic and vegetation structure changes during forest succession after disturbances caused by small-scale gold mining in Madre de Dios (Peru). We compared the floristic and vegetation structure of a reference forest against three sites with different periods of abandonment after mining (5, 11 and 23-years). Three 20 × 60 m plots were defined on each site, and all tree species with a DBH >1 cm within the plots were inventoried. To evaluate species diversity and similarity, the Importance Value, effective numbers of species (0D, 1D, and 2D), and Chao-Jaccard similarity index were calculated. We used the Nonmetric multidimensional scaling for similarity ordination and the PERMANOVA test to evaluate differences in floristic composition. We recorded 129 tree species in the study areas and statistically significant differences between initial and intermediate stages were observed regarding floristic composition, basal area, height, and DBH. The transition from the initial successional stage to the reference forest produces an increase in basal area, species diversity, and floristic similarity. The 23-year-old stand had more species in common with the 11-year-old stand than the reference forest. Our results showed a high proportion of pioneer species and anemochory dispersal syndrome in the initial successional stages, but they decreased in later stages of the chronosequence. The floristic and structural attributes of forests throughout the chronosequence showed a fast recovery during secondary succession. After 23 years, the recovery of tree species density was 77 % of reference forest, while the relative recovery of species composition was much slower, on average 23 %. These results provide essential information to guide the selection of suitable species in ecological restoration projects after abandonment. Implementing forest restoration strategies based on reliable information to accelerate the process of vegetation succession is critical for recuperating areas degraded by gold mining at the Peruvian Amazon.
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•Fast recovery of floristic and structural attributes of secondary forests after mining.•Species density and tree diversity increased with time since abandonment. These values are all lower than those found in the reference forest.•Forest structure recovered faster than species composition.•Pioneer tree species dominated the initial successional stage and promoted the reestablishment of diversity.