DNA metabarcoding reveals host-specific communities of arthropods residing in fungal fruit bodies.

Lisa Fagerli Lunde,Sundy Maurice,Anne Sverdrup-Thygeson,Luis Morgado,Håvard Kauserud,Lynne Boddy,Tone Birkemoe,Rannveig M Jacobsen

doi:10.1098/rspb.2021.2622

Abstract

Biological communities within living organisms are structured by their host's traits. How host traits affect biodiversity and community composition is poorly explored for some associations, such as arthropods within fungal fruit bodies. Using DNA metabarcoding, we characterized the arthropod communities in living fruit bodies of 11 wood-decay fungi from boreal forests and investigated how they were affected by different fungal traits. Arthropod diversity was higher in fruit bodies with a larger surface area-to-volume ratio, suggesting that colonization is crucial to maintain arthropod populations. Diversity was not higher in long-lived fruit bodies, most likely because these fungi invest in physical or chemical defences against arthropods. Arthropod community composition was structured by all measured host traits, namely fruit body size, thickness, surface area, morphology and toughness. Notably, we identified a community gradient where soft and short-lived fruit bodies harboured more true flies, while tougher and long-lived fruit bodies had more oribatid mites and beetles, which might reflect different development times of the arthropods. Ultimately, close to 75% of the arthropods were specific to one or two fungal hosts. Besides revealing surprisingly diverse and host-specific arthropod communities within fungal fruit bodies, our study provided insight into how host traits structure communities.

Highlights

Biological communities in or on living organisms are structured by their host’s traits, such as size or persistence, which can influence both the survival and biotic interactions of species in the community via selection processes [1,2,3]
Using DNA metabarcoding, we characterized the arthropod communities in living fruit bodies of 11 wood-decay fungi from boreal forests and investigated how they were affected by different fungal traits
We explore the importance of host traits for diversity and community composition in a poorly explored interaction network: arthropods inside living fruit bodies of fungi

Summary

Introduction

Biological communities in or on living organisms are structured by their host’s traits, such as size or persistence, which can influence both the survival and biotic interactions of species in the community via selection processes [1,2,3]. We compared the diversity and community composition of arthropods in living fruit bodies of 11 species of wood-decay fungi. For each of the 11 fungal species, we compiled information on six fruit body traits that potentially impact arthropod communities (electronic supplementary material, table S1) [19,42,43] These were the fruit body size, mean fruit body thickness (cm), mean hymenophore surface area (cm2), morphology (resupinate/ pileate), persistence (short- and long-lived; corresponds to annual and perennial, respectively) and hyphal system complexity (monomitic/dimitic/trimitic). Six fruit body traits (size, mean thickness, mean surface area, morphology, persistence and hyphal system complexity) were inferred as explanatory variables and tested as singlecovariate models with host species as a random effect and restricted maximum likelihood as the optimization criterion. Shannon diversity (c) amylap fompin fomros glosep poscae antser phecen phefer phenig phevit triabi relative abundance

50 Arachnida

Results

Discussion

Findings

Conclusion and perspectives