The impact of spatial isolation and local habitat conditions on colonization of recent forest stands by ectomycorrhizal fungi

Abstract

Successful colonization of empty habitat patches depends both on the capacity of a species to reach the patch and its ability to establish and persist. Getting better insights into the various factors that affect colonization success is especially relevant in the context of restoration projects that aim at restoring biodiversity in newly created habitats like afforestation. While it is generally known that soil microbial communities play a key role in forest ecosystems, it remains largely unknown how they recover in recently restored forests on former agricultural land. Here, we used next-generation sequencing to investigate how spatial isolation and abiotic conditions affected the diversity and composition of ectomycorrhizal fungal communities in recent forest stands. Soil samples and roots of Quercus robur were sampled in ancient forest stands and recent stands both adjacent and spatially isolated from the ancient stands. Our results showed that ectomycorrhizal fungal community composition was affected by a combination of isolation and local soil conditions. Although communities of recently restored forest stands more resembled those of ancient stands when they immediately bordered ancient forest, there were still significant differences in community composition, most likely as a result of differences in edaphic conditions. Isolated stands had a significantly lower diversity and were mainly colonized by highly dispersive species. Overall, these results indicate that ectomycorrhizal fungal communities may develop faster in recent forest stands connected to ancient forest than in isolated stands, and that isolated stands may remain impoverished for many decades or even for indeterminate time.

Effects of host species, environmental filtering and forest age on community assembly of ectomycorrhizal fungi in fragmented forests

“…Fine-scale analyses of the correlation between genotypic similarity and geographic distance in several Russula species found limited gene flow via spore dispersal (Wang et al, 2015). In a study on EcM fungal communities in recent oak stands that were either isolated from or connected to ancient forest, Russula was more abundant in recent stands connected to ancient forest than in isolated stands (Boeraeve et al, 2018), suggesting that Russula species are unable to travel large distances across a hostile landscape matrix. Indicator species analysis on the four age classes revealed a similar pattern with indicator OTUs of the youngest age class belonging to Cenococcum, Tomentella and Sebacina, all known to be efficient dispersers.…”

“…Previous research has shown that, although these root-associated symbionts show large differences in dispersal capacity, even highly dispersive species show rapidly decreasing spore loads with increasing distance from source patches (Peay et al, 2012). As a consequence, EcM fungal communities in newly established habitats may be highly affected by dispersal limitation (Peay et al, 2010) and it is therefore not unlikely that spatial isolation and overall landscape connectivity contribute to EcM fungal community assembly (Peay and Bruns, 2014;Vannette et al, 2016;Boeraeve et al, 2018).…”

The Utility of Macroecological Rules for Microbial Biogeography

“…Frontiers in Ecology and Evolution | www.frontiersin.org (Heino and Soininen, 2006;Heino and Tolonen, 2018;Rocha et al, 2018;Vilmi et al, 2019) B T (Godon et al, 2016;Moeller et al, 2017) Microbe-Microbe Competition Davison et al, 2015;Lu et al, 2018), B A (Fuhrman et al, 2008;Stomp et al, 2011;Kruk et al, 2012;Sul et al, 2013;Vogt et al, 2019) Okie et al, 2015;Zhou et al, 2016;Xu et al, 2017;Wu et al, 2018) B T (Loudon et al, 2016;Moeller et al, 2017), F T (Peay et al, 2007(Peay et al, , 2010(Peay et al, , 2012Bahram et al, 2013;Vannette et al, 2016;Glassman et al, 2017a,b;Boeraeve et al, 2018), P T (Ishtiaq et al, 2010;Spurgin et al, 2012)A A (Whitaker et al, 2003), B A (Darcy et al, 2018), F T (Li et al, 2020), P A (Soininen et al, 2007;Lepère et al, 2013;Santos et al, 2016) F T (Green et al, 2004) Unknown Mechanism B A (Meador et al, 2009), P A (Soininen and Kokocinski, 2006)…”

Host Phylogenetic Relatedness and Soil Nutrients Shape Ectomycorrhizal Community Composition in Native and Exotic Pine Plantations

“…Such low-diversity limitations may reflect both neutral (dispersal) and niche processes (abiotic factors; e.g., [14][15][16][17]). Studies show that longer distances (>10 km) may limit the stochastic dispersal of fungal propagules from one location (native forest) to another (plantation) whereas deterministic traits such as dispersal via spores [14,18] versus mycorrhizal root tips and hyphal networks may operate at finer scales [19][20][21][22]. In addition, biotic (e.g., host nutrient demands, seed dispersal) and abiotic factors (e.g., soil chemistry) may facilitate ECM fungal species with physiological and ecological adaptations depending on the environmental context [23].Recent evidence has demonstrated that phylogenetic distance between exotic and native hosts might explain their (dis)similarities in ECM community composition and richness [24,25].…”