Community assembly and metaphylogeography of soil biodiversity: Insights from haplotype‐level communityDNAmetabarcoding within an oceanic island

Abstract

Most of our understanding of island diversity comes from the study of aboveground systems, while the patterns and processes of diversification and community assembly for belowground biotas remain poorly understood. Here, we take advantage of a relatively young and dynamic oceanic island to advance our understanding of ecoevolutionary processes driving community assembly within soil mesofauna. Using whole organism community DNA (wocDNA) metabarcoding and the recently developed metaMATE pipeline, we have generated spatially explicit and reliable haplotype‐level DNA sequence data for soil mesofaunal assemblages sampled across the four main habitats within the island of Tenerife. Community ecological and metaphylogeographic analyses have been performed at multiple levels of genetic similarity, from haplotypes to species and supraspecific groupings. Broadly consistent patterns of local‐scale species richness across different insular habitats have been found, whereas local insular richness is lower than in continental settings. Our results reveal an important role for niche conservatism as a driver of insular community assembly of soil mesofauna, with only limited evidence for habitat shifts promoting diversification. Furthermore, support is found for a fundamental role of habitat in the assembly of soil mesofauna, where habitat specialism is mainly due to colonization and the establishment of preadapted species. Hierarchical patterns of distance decay at the community level and metaphylogeographical analyses support a pattern of geographic structuring over limited spatial scales, from the level of haplotypes through to species and lineages, as expected for taxa with strong dispersal limitations. Our results demonstrate the potential for wocDNA metabarcoding to advance our understanding of biodiversity.

Towards understanding insect species introduction and establishment: A community‐level barcoding approach using island beetles

“…However, it is recognized that distinguishing between native and introduced status is often difficult in natural communities (Andersen et al, 2019). Thus, to further refine inferences between NATnotend and INT species status, we used high barcode sequence matching (≥99%) to individuals sampled outside the macaronesian region as evidence that inferred NATnotend species are more likely of introduced origin (Andújar et al, 2022; Cicconardi et al, 2017).…”

Collective and harmonized high throughput barcoding of insular arthropod biodiversity: Toward a Genomic Observatories Network for islands

“…With the ability to now obtain reliable haplotype-level data from metabarcode sequence output (Andújar et al, 2021), it is possible to implement both multiplex barcode and wocDNA metabarcoding to explore the patterns and drivers of diversification and speciation across arthropod assemblages. Andújar et al (2022) demonstrate the implementation of such a metaphylogeographic approach with wocDNA barcoding to understand the relative roles of ecological and geographical drivers for diversification among soil arthropods within a single oceanic island. Extending such an approach across multiple islands within archipelagos can provide baseline data on the relative importance of ecological and geographical speciation within many as yet largely unstudied fractions of arthropod diversity.…”

“…HTS barcoding can greatly contribute to knowledge deficits concerning species inventory, species distributions, the geographic structuring of genetic variation within species, and the factors that explain this structure (Arjona et al, 2022). With specific regard to islands, the generation of HTS barcode data within an iGON opens the door to improved investigation of fundamental island biogeographic theory using arthropods (Andújar et al, 2022; Armstrong et al, 2022; Lim et al, 2022). Finally, island communities can be leveraged to address the recognized need for integration across the disciplines of macroecology and macroevolution, where synthesizing data, tools and perspectives is required (McGill et al, 2019).…”

“…They revealed that climatic niche conservatism is an important factor shaping ecological assembly across elevation, thus implicating topographic complexity as an important driver of diversification. Similarly, wocDNA metabarcoding approaches to characterize soil arthropod assemblages on the islands of Tenerife and Cyprus have revealed strong habitat filtering and dispersal limitations as drivers of community assembly within islands (Andújar et al, 2022; Noguerales et al, 2022).…”

Contrasting results of multiple species delimitation approaches cause uncertainty in synecological studies: A case study on Sri Lankan chafers

“…A haplotype‐based assessment of biodiversity was assumed to be completely independent from species concepts or delimitation methods including their assumptions (Thormann et al, 2016). Such an approach was currently in use in several ecological and metabarcoding studies (Andujar et al, 2022; Gálvez‐Reyes et al, 2020; Noguerales et al, 2021). It has been shown to work well for exploring macroecological patterns in poorly known biota (Baselga et al, 2013; Papadopoulou et al, 2011) and predicting large‐scale biodiversity patterns by using haplotype diversity as a proxy for genetic and species diversity (Papadopoulou et al, 2011; see also Cruz‐Salazar et al, 2021).…”