Desarrollo estructural y composición florística arbórea en áreas afectadas por minería aurífera en la Amazonía peruana: a 20 años de su reforestación

Abstract

Desarrollo estructural y composición florística arbórea en áreas afectadas por minería aurífera en laAmazonía peruana: a 20 años de su reforestación Development of forest structure and tree floristic composition on affected gold mined sites in the Peruvian Amazon: 20 years after reforestation

Resilience of Aboveground Biomass of Secondary Forests Following the Abandonment of Gold Mining Activity in the Southeastern Peruvian Amazon

“…However, the expansion of deforestation and forest degradation in Madre de Dios persists [19,88], resulting in the emission of carbon into the atmosphere [16]. The mean AGB determined in 20-25 years of recovery, 198 ± 115 Mg ha −1 in areas of suction pumping mining and 45 ± 78 Mg ha −1 in areas recovering from heavy machinery mining in this study is less than the mean AGB reported for tropical Amazon forest from Madre de Dios (230-450 Mg ha −1 ) [39,86,89]. This suggests a more rapid recovery of AGB in suction pumping mining forest stands in comparison to those of heavy machinery, because >20-year-old suction pumping forest stands store similar amounts of carbon as naturally regenerating forests on abandoned deforested lands (secondary forests from non-mining impacts) of similar age [4,90].…”

“…The lower similarity in species composition (<20% in higher successional stages, Table S3) across the chronosequence suggests a slower recovery compared to those of AGB, species diversity and forest structure. This pattern has been observed for other tropical forests [37] and in secondary forests after mining in the Peruvian Amazon [20,[39][40][41]. This highlights the need to promote active restoration strategies to establish both economically and ecologically important valuable native tree species [37].…”

“…The annual average rainfall ranges between 1500 mm and 2860 mm [48]. The average annual temperature is around 25 • C, ranging from 16 • C to 39 • C. During the dry season, from June to September, precipitation is lower than 100 mm per month [39,41] (Figure S1).…”

“…These results indicate that heavy machinery mining may have a considerable negative effect on species diversity [21], because suction pumping mining forest stands harbor on average approximately two times more species than heavy machinery stands. Given that species diversity usually starts near zero with no woody plants, due to the elimination of vegetation cover [39,41,42] and severe soil degradation [20,43,44,54] by goldmining, our results highlight the lower impact of suction pumping mining on landscape structure, which promotes an increase over time as new species become established [79], and facilitates the faster recovery across the landscape [80]. The lower species diversity after mining abandonment may be explained by a higher dominance (IVI > 10, Table 3) or monodominance [30,95] of pioneer species in 0-5-year-old stands, due to higher tolerance of certain species to unfavorable soil conditions [95] generated by goldmining activities in the study area.…”

“…For this purpose, the chronosequence approach has been one of the most widely used [38]. However, there are few studies that analyze the recovery of biomass in secondary succession after abandonment by mining activities [39], compared to studies in areas degraded by other activities such as agriculture or livestock [21].…”