DNA-Based Arthropod Diversity Assessment in Amazonian Iron Mine Lands Show Ecological Succession Towards Undisturbed Reference Sites

Abstract

Human activities change natural landscapes, and in doing so endanger biodiversity and associated ecosystem services. To reduce the net impacts of these activities, such as mining, disturbed areas are rehabilitated and restored. During this process, monitoring is important to ensure that desired trajectories are maintained. In the Carajás region of the Brazilian Amazon, exploration for iron ores has transformed the original ecosystem; natural forest and a savanna formation with lateritic iron duricrust outcrops named canga. Here, native vegetation is logged and topsoil removed and deposited in waste piles along with mine waste. During rehabilitation, these waste piles are hydroseeded with non-native plant species to achieve rapid revegetation. Further, seeds of native canga and forest plant species are planted to point ecological succession towards natural ecosystems. In this study, we investigate diversity and composition of the arthropod community along a post-mining rehabilitation and restoration gradient, taking seasonality and primer bias into account. We use DNA metabarcoding of bulk arthropod samples collected in both the dry and rainy seasons from waste-pile benches at various stages of revegetation: non-revegetated exposed soils, initial stage with one-to-three-year-old stands, intermediate stage with four-to-five-year-old stands, and advanced stage with six-to-seven-year-old stands. We use samples from undisturbed cangas and forests as reference sites. In addition, we vegetation diversity and structure were measured to investigate relations between arthropod community and vegetation structure. Our results show that, over time, the arthropod community composition of the waste piles becomes more similar to the reference forests, but not to the reference cangas. Nevertheless, even the communities in the advanced-stage waste piles are different from the reference forests, and full restoration in these highly diverse ecosystems is not achieved, even after 6 to 7 years. Finally, our results show seasonal variation in arthropod communities and primer bias.

Spread of Bambusa bambos (L.) Voss influences litter‐dwelling arthropod communities in native forests: a case study from Sri Lanka

“…Our results show that the abundance and order richness of litter‐dwelling arthropods was higher in bamboo than in non‐bamboo forests across all three study sites (Figure 1), indicating a potential facilitative role of the B. bambos spread on litter‐dwelling arthropods. Previous studies observed a strong correlation between litter‐dwelling arthropod communities and specific features of the extant vegetation (Basset et al, 2012; Lynggaard et al, 2020; Zhang et al, 2016). Vegetation features such as tree density and canopy gaps are known to modify forest floor characteristics such as soil moisture, shade and the amount of litter, and in turn influencing soil‐dwelling faunal communities (Cerda et al, 2015; Higgins et al, 2017; Jacobs et al, 2018; Perry et al, 2018; Swengel & Swengel, 2007).…”

“…Previous studies observed a strong correlation between litterdwelling arthropod communities and specific features of the extant vegetation (Basset et al, 2012;Lynggaard et al, 2020;Zhang et al, 2016). Vegetation features such as tree density and canopy T A B L E 1 Summary of SIMPER analysis showing the most dominant arthropod orders that contribute to the dissimilarity of arthropod assemblages between in bamboo-(BM) and non-bamboo (NB) forest communities at Galboda, Moragolla and Maragamuwa in the Central Province of Sri Lanka gaps are known to modify forest floor characteristics such as soil moisture, shade and the amount of litter, and in turn influencing soildwelling faunal communities (Cerda et al, 2015;Higgins et al, 2017;Jacobs et al, 2018;Perry et al, 2018;Swengel & Swengel, 2007).…”

Metabarcoding advances agricultural invertebrate biomonitoring by enhancing resolution, increasing throughput, and facilitating network inference

“…Studies have also combined malaise traps with metabarcoding to assess changes in species richness in conservation areas (Köthe et al, 2023), biodiversity in restored environments (Lynggaard et al, 2020) and temporal changes in invertebrates across agricultural (Hausmann et al, 2022) and forest landscapes (Kirse et al, 2021), and to create species inventories (Li et al, 2023). Due to the design of the trap, specimens are immediately stored in a suitable preservative, such as a high purity ethanol (deWaard et al, 2019;Kirse et al, 2021;Swenson et al, 2022), requiring no modifications.…”

Strategies for sample labelling and library preparation in DNA metabarcoding studies

“…The ligated adapters can themselves contain indices, which eliminates the need for a second PCR step (e.g., Carøe & Bohmann, 2020 ; Thomsen et al, 2016 ), or the adapter ligation can be followed by a PCR step with indexed primers (e.g., Bohmann et al, 2018 ; Hope et al, 2014 ). This approach was first demonstrated by Binladen et al ( 2007 ) on the 454 FLX platform and has since been used in for example, Shehzad, McCarthy, et al ( 2012 ), Hibert et al ( 2013 ), Hope et al ( 2014 ), Thomsen et al ( 2016 ), Apothéloz‐Perret‐Gentil et al ( 2017 ), Sigsgaard et al ( 2017 ), Bakker et al ( 2017 ), Kocher et al ( 2017 ), Thomsen and Sigsgaard ( 2019 ), and Lynggaard et al ( 2020 ) (Figure 2e ). In this approach, each library pool of PCR replicates is a sequencing library and is returned as a separate fastq file, each of which can contain data from a large number of tagged PCR replicates.…”