Land‐use history alters the diversity, community composition and interaction networks of ectomycorrhizal fungi in beech forests

Abstract

1. Forests have expanded across Europe over the last centuries as a consequence of farmland (agricultural and pasture) abandonment. Agricultural practices usually increase soil fertility and reduce the diversity and abundance of ectomycorrhizal (ECM) fungi, essential mutualists of many woody species in temperate and Mediterranean forests. The recovery of this biotic interaction after the cessation of human activities is, thus, crucial for the re-establishment of functional forest ecosystems.2. Here we addressed the legacies of past land use and the recovery of the mutualism between ECM fungi and Fagus sylvatica trees in recent beech forests (<50 years) in Northeast Spain. Soil and root samples were collected in six long-established and eight recent beech forests to analyse soil abiotic properties and the ECM fungi associated with beech roots (Illumina DNA metabarcoding of ECM tips).3. Up to 609 amplicon sequence variants (ASVs) of ECM fungi were identified, with 220 ASVs found in both forest types. Recent forests had a significantly lower soil organic matter and phosphorus content, which had a significant effect on the community structure of ECM fungi in beech roots. Moreover, beech trees in recent forests interacted with less fungal taxa but had a higher relative abundance of Ascomycota. Tarzetta spp. (Ascomycota, Pezizales) and Lactarius blennius (Basidiomycota, Russulales) emerge as the particular taxa associated with recent and long-established forests respectively. 4. More specialized mutualistic networks with a lower species normalized degree were found in recent forests, which might result in a lower quality and resilience of the ECM mutualism. 5.Synthesis. Land-use history modulated the mycorrhizal symbiosis in regenerating beech forests through changes in soil organic matter and nitrogen, which were the main drivers of the differences in fungal community composition and functional types associated with beech trees in recent forests.

Global patterns in endemicity and vulnerability of soil fungi

“…For fungi, n = 156 and n = 28 for continent and island ecoregions, respectively; for other groups, n = 76 and n = 14 for continent and island ecoregions, respectively. be more influential locally (e.g., Correia et al, 2021;van der Linde et al, 2018) and are partly accounted for by land cover change in this study. Furthermore, while here we calculated average vulnerabilities by summing the effects of individual drivers, global change impacts tend to be synergistic (Rillig et al, 2019), so actual vulnerabilities may be much higher.…”

Mycorrhizal Fungi Associated With Juniper and Oak Seedlings Along a Disturbance Gradient in Central Mexico

“…Both families tend to be hostgeneralists that are abundant in subtropical and tropical oak forests (García-Guzmán et al, 2017). Some species from these families also have short-exploration type hyphae that allow them to regenerate faster compared to taxa with greater extraradical hyphae, thus recovering more easily from disturbances (Deslippe et al, 2011;Correia et al, 2021). To date a limited number of ECM fungal species, mostly from temperate and boreal regions, have been tested for reforestation purposes (Policelli et al, 2020).…”

“…The effect of disturbance may contribute to the presence of rare ECM taxa (Kałucka and Jagodziński, 2016). For example, Tarzetta is an early-successional ascomycete that abundantly colonizes seedlings across different forest ecosystems, particularly in sites that face environmental stress or disturbance (Correia et al, 2021). Similarly, species of Peziza are stress-tolerant taxa that can intensely colonize roots following fire disturbances (Pulido-Chavez et al, 2021), while the basidiomycete genus Entoloma is frequently found in fragmented young forest stands and is not very prone to dispersal limitation (Boeraeve, 2019).…”

Ectomycorrhizal Networks in the Anthropocene: From Natural Ecosystems to Urban Planning

“…From a plant-centered perspective, the reported pauperization effect of forest exploitation on ECM communities may alter the topology of ECM networks. Early evidence of age influence on network topology already exists: using high-throughput sequencing of soils, Correia et al (2021) reported contrasted ECM network topologies along a chronosequence of Fagus sylvatica forest establishment, plant nodes in long-established forests presenting higher numbers of connection links than in recent patches. From a fungal perspective, silvicultural practices tend to reduce the number and diversity of available plant nodes for fungal genets.…”

“…As organisms are highly dependent on soil physico-chemical conditions, ECM fungal communities are critical components of soil history by responding to short-term as well as long-term human impacts (Dupouey et al, 2002). Inevitably, the composition and dynamics of ECM community are profoundly influenced by forest management (Tomao et al, 2020) and anthropic disturbance derived from agronomic practices in man-made ecosystems (Olivera et al, 2014;Taschen et al, 2015), with cascading effects on the underlying interaction networks (Correia et al, 2021).…”