مطالعه تنوع زيستي بندپايان با استفاده از روش متاباركدينگ دناي محيطي از بستر جنگل هاي هيركاني (مازندران، منطقه حفاظت‌شده كجور)

Arthropod biodiversity is fundamental to the functioning an‎d stability of forest ecosystems, playing critical ecological roles such as organic matter decomposition, enhancing soil fertility, pollination, an‎d regulating pest populations. Despite their importance, the forest floor habitats that support a vast diversity of these soil-dwelling arthropods—including soil, leaf litter, an‎d moss layers—are frequently overlooked. This is particularly true in Iranʹs Hyrcanian forests, a recognized biodiversity hotspot, where the arthropod diversity within these microhabitats remains largely unexplored. The lack of such critical knowledge hinders the development of effective conservation strategies. Traditional morphological identification methods are often insufficient for comprehensive biodiversity assessment due to their reliance on high taxonomic expertise an‎d time-consuming processes. In contrast, environmental DNA (eDNA) metabarcoding allows for the simultaneous an‎d precise identification of species directly from environmental samples. This study employed eDNA metabarcoding to: (1) characterize the species composition of arthropods in forest floor habitats across an elevational gradient, (2) examine the effects of elevation, moss substrate type, an‎d DNA extraction method on community composition. During summer 2023, we collected a total of 91 environmental samples from the Tarbiat Modares University Research Forest along three elevational transects: 200-700 m, 700-1200 m, an‎d 1200-1700 m. The sample set included 17 moss samples from tree trunks, 11 from rock surfaces, 31 soil samples, an‎d 32 leaf litter samples. Environmental DNA was extracted using two methods: the DNeasy PowerSoil Pro Kit (Qiagen) an‎d the CTAB protocol. The cytochrome c oxidase subunit I (COI) gene was targeted for amplification using specific primers to inhibit plant DNA amplification, followed by sequencing on an Illumina platform. Resulting sequences were processed an‎d taxonomically classified against the BOLD an‎d GenBank databases. While leaf litter samples were excluded from sequencing due to challenges in obtaining high-quality DNA, successful analysis of moss an‎d soil samples revealed a total of 2,032 unique zOTUs. These represented 60 species from 77 families (20 orders) in moss, an‎d 63 species from 42 families (15 orders) in soil. Our findings include nine new species records for the region an‎d confirm the dominance of Diptera (flies) an‎d Acari (mites) within these communities. This research confirms the utility of moss an‎d soil as effective substrates for eDNA-based biodiversity monitoring an‎d represents a significant step forward in uncovering the hidden genetic diversity of the Hyrcanian forests.

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