First Evidence That Nematode Communities in Deadwood Are Related to Tree Species Identity and to Co-Occurring Fungi and Prokaryotes

Abstract

Nematodes represent a diverse and ubiquitous group of metazoans in terrestrial environments. They feed on bacteria, fungi, plants, other nematodes or parasitize a variety of animals and hence may be considered as active members of many food webs. Deadwood is a structural component of forest ecosystems which harbors many niches for diverse biota. As fungi and bacteria are among the most prominent decomposing colonizers of deadwood, we anticipated frequent and diverse nematode populations to co-occur in such ecosystems. However, knowledge about their ability to colonize this habitat is still limited. We applied DNA-based amplicon sequencing (metabarcoding) of the 18S rRNA gene to analyze nematode communities in sapwood and heartwood of decaying logs from 13 different tree species. We identified 247 nematode ASVs (amplicon sequence variants) from 27 families. Most of these identified families represent bacterial and fungal feeders. Their composition strongly depended on tree species identity in both wood compartments. While pH and water content were the only wood properties that contributed to nematodes’ distribution, co-occurring fungal and prokaryotic (bacteria and archaea) α- and β-diversities were significantly related to nematode communities. By exploring thirteen different tree species, which exhibit a broad range of wood characteristics, this study provides first and comprehensive insights into nematode diversity in deadwood of temperate forests and indicates connectivity to other wood-inhabiting organisms.

Nematodes in the Pine Forests of Northern and Central Greece

“…On the other hand, Mononchidae and Quadsianematidae are more sensitive to disturbance and are commonly present in more stable environments [102]. Nevertheless, the presence of many different groups of nematodes appears feasible given the great variety of available resources as it is suggested by Moll et al [103].…”

“…Many factors affect both nematode presence and community structure such as tree species, environmental variables, as well as the time of the year that sampling took place. For example, Moll et al [103] who studied nematode communities from deadwood of 13 different tree species came to the conclusion that nematode composition was strongly related to tree species as well as the presence of other co-occurring biota such as fungi and prokaryotes. As already mentioned, environmental variables play an important role in nematode community composition.…”

Nematode–Microbe Complexes in Soils Replanted with Apple

“…The following PCR cycler condition was used: Initial denaturation of 5 min at 94 • C, 25 cycles of (94 • C for 45 s; 54 • C for 30 s; 72 • C for 1 min) and a final extension of 10 min at 72 • C. The resulting PCR product was purified using the High Pure PCR Purification kit (Roche Diagnostics, Rotkreuz, Switzerland) following the manufacturer's instructions. Barcoded amplicon sequencing of the 18S rRNA genes was done by 2 × 300 bp paired-end high-throughput sequencing (MiSeq Reagent kit v3) on an Illumina MiSeq platform (Illumina, San Diego, CA, USA) at the Department of Soil Ecology of the Helmholtz Centre for Environmental Research-UFZ, Halle, Germany [38].…”

Nematode-Microbe Complexes in Soils Replanted with Apple

“…The resulting PCR product was purified using the High Pure PCR Purification kit (Roche Diagnostics GmbH) following the manufacturer's instructions. Barcoded amplicon sequencing of the 18S rRNA genes was done by 2 x 300 bp paired-end high-throughput sequencing (MiSeq Reagent kit v3) on an Illumina MiSeq platform (Illumina, San Diego, CA, United States) at the Department of Soil Ecology of the Helmholtz Centre for Environmental Research -UFZ, Halle, Germany [36].…”