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A) Leaf nitrogen (N) and (B) phosphorus (P) concentrations and (C) N:P ratio of Acacia rostellifera and Melaleuca systena with increasing soil age. Means and 95% confidence intervals (CI) are shown n = 10. Different letters indicate significant (P ≤ 0.05) differences among soil ages based on post hoc Tukey tests. Black dashed lines indicate thresholds for N or P limitation, following Güsewell (2004). Gray area indicates thresholds for N or P limitation based on Koerselman and Meuleman (1996).
Source publication
Changes in soil nutrient availability during long-term ecosystem development influence the relative abundances of plant species with different nutrient-acquisition strategies. These changes in strategies are observed at the community level, but whether they also occur within individual species remains unknown. Plant species forming multiple root sy...
Contexts in source publication
Context 1
... [N] followed a similar pattern for both species across the chronosequence, being highest on intermediate-aged soils (P ≤ 0.003; Fig. 4A; Table S2), where soil total [N] (Table 1). Leaf [N] was higher in A. rostellif- era than in M. systena across all soil ages (P ≤ 0.001). Leaf [P] decreased from young to old soils for both spe- cies (P ≤ 0.001; Fig. 4B; Table S2). Leaf [P] was lower in A. rostellifera than in M. systena on young and intermedi- ate-aged soils (P ≤ ...
Context 2
... [N] followed a similar pattern for both species across the chronosequence, being highest on intermediate-aged soils (P ≤ 0.003; Fig. 4A; Table S2), where soil total [N] (Table 1). Leaf [N] was higher in A. rostellif- era than in M. systena across all soil ages (P ≤ 0.001). Leaf [P] decreased from young to old soils for both spe- cies (P ≤ 0.001; Fig. 4B; Table S2). Leaf [P] was lower in A. rostellifera than in M. systena on young and intermedi- ate-aged soils (P ≤ 0.001), but on old soils both species had similarly low leaf [P] (P ≥ 0.2). Leaf N:P ratio increased from young to old soils in both species (P ≤ 0.001; Fig. 4C; Table S2). On intermediate-aged soils, the N:P ratio of A. ...
Context 3
... Leaf [P] decreased from young to old soils for both spe- cies (P ≤ 0.001; Fig. 4B; Table S2). Leaf [P] was lower in A. rostellifera than in M. systena on young and intermedi- ate-aged soils (P ≤ 0.001), but on old soils both species had similarly low leaf [P] (P ≥ 0.2). Leaf N:P ratio increased from young to old soils in both species (P ≤ 0.001; Fig. 4C; Table S2). On intermediate-aged soils, the N:P ratio of A. rostellifera (65 AE 7.9) pointed toward P limitation, while that of M. systena (2.1 AE 0.5) pointed toward N ...
Citations
... Moreover, mycorrhizal fungi influence plant interactions with other soil microbes, which are pivotal for nitrogen fixation, phosphorus uptake, and protection against pathogens . Mycorrhizal fungi play a crucial role in terrestrial ecosystems by regulating nutrient and carbon cycles, and affecting soil structure and ecosystem multi-functionality (Brundrett 1991;Albornoz et al. 2016). Extensive investigation has revealed significant variations among different mycorrhizal fungus species, highlighting potential implications for the conservation and management of specific soil communities to support tree growth in natural forests (van Der Heijden et al. 2015;Anthony et al. 2022). ...
Taxus, a genus of conifers known for its medicinal significance, faces various conservation challenges with several species classified under different threat categories by the IUCN. The overharvesting of bark and leaves for the well-known chemotherapy drug paclitaxel has resulted in its population decline. Exploring the mycorrhizal relationship in Taxus is of utmost importance, as mycorrhizal fungi play pivotal roles in nutrition, growth, and ecological resilience. Taxus predominantly associates with arbuscular mycorrhizal fungi (AM), and reports suggest ectomycorrhizal (EM) or dual mycorrhizal associations as well. This review consolidates existing literature on mycorrhizal associations in Taxus species, focusing on structural, physiological, and molecular aspects. AM associations are well-documented in Taxus, influencing plant physiology and propagation. Conversely, EM associations remain relatively understudied, with limited evidence suggesting their occurrence. The review highlights the importance of further research to elucidate dual mycorrhizal associations in Taxus, emphasizing the need for detailed structural and physiological examinations to understand their impact on growth and survival.
... Key studies are needed to test the NeP interactions in AM trees. At the level of EcMdAM comparisons, it is worth integrating this conceptual understanding with that of Albornoz et al. (2016), who found that on roots of Acacia rostellifera, an N 2 -fixing dual mycorrhizal legume (where N supply should be sufficient), under high inorganic P availability AMF dominate, whereas as soils age and P is increasingly found in organic forms, EcMF dominate. They hypothesized that this trend was driven by the ability of the EcMF to access organic P via phosphatases, a function that is more limited (Phillips et al., 2013;Rosling et al., 2016), but not absent (Jiang et al., 2021) in AMF. ...
... Exclusive plant-MFRE symbioses seem to be rare, with the majority of land plants forming simultaneous associations alongside AM fungi (Rimington et al., 2015), with recent research highlighting a potential functional complementarity between the two groups (Field et al., 2019). Traditionally, MFRE fungi have been functionally associated with the facilitation of plant P uptake and occur commonly in soils with low P availability (Smith et al., 2015;Albornoz et al., 2016;Orchard et al., 2017b). However recent exploration of MFRE function in wild-collected plant based systems showed that MFRE symbionts transferred significantly more 15 N tracer compared to 33 P tracer to an earlydiverging vascular plant than to Haplomitropsida liverworts in comparable experiments (Field et al., 2016). ...
Background
The soil microbiome plays a pivotal role in maintaining ecological balance, supporting food production, preserving water quality, and safeguarding human health. Understanding the intricate dynamics within the soil microbiome necessitates unravelling complex bacterial-fungal interactions (BFIs). BFIs occur in diverse habitats, such as the phyllosphere, rhizosphere, and bulk soil, where they exert substantial influence on plant-microbe associations, nutrient cycling, and overall ecosystem functions. In various symbiotic associations, fungi form mycorrhizal connections with plant roots, enhancing nutrient uptake through the root and mycorrhizal pathways. Concurrently, specific soil bacteria, including mycorrhiza helper bacteria (MHB), play a pivotal role in nutrient acquisition and promoting plant growth. Chemical communication and biofilm formation further shape plant-microbial interactions, affecting plant growth, disease resistance, and nutrient acquisition processes.
Scope
Promoting synergistic interactions between mycorrhizal fungi and soil microbes holds immense potential for advancing ecological knowledge and conservation. However, despite the significant progress, gaps remain in our understanding of the evolutionary significance, perception, functional traits, and ecological relevance of BFIs. Here we review recent findings obtained with respect to complex microbial communities - particularly in the mycorrhizosphere - and include the latest advances in the field, outlining their profound impacts on our understanding of ecosystem dynamics and plant physiology and function.
Conclusions
Deepening our understanding of plant BFIs can help assess their capabilities with regard to ecological and agricultural safe-guarding, in particular buffering soil stresses, and ensuring sustainable land management practices. Preserving and enhancing soil biodiversity emerge as critical imperatives in sustaining life on Earth amidst pressures of anthropogenic climate change. A holistic approach integrates scientific knowledge on bacteria and fungi, which includes their potential to foster resilient soil ecosystems for present and future generations.
... To account for sources of variation outside of our experimental design, we also included tree DBH as a covariate. As larger older trees can have different microbiomes than smaller younger trees and these effects differ among species (Albornoz et al. 2016), we also included interactions between DBH and the combination of tree type and soil sterilization. We did not include its interactions with all fixed predictors because we had no specific hypotheses and to minimize model complexity. ...
Purpose
Most plants interact with soil biota that positively or negatively affect seedling performance. These plant-soil feedbacks (PSFs) can strongly affect recruitment, potentially for years after death. We tested whether PSFs persisted following death for Populus tremuloides Michx. (aspen) and if these effects were environment dependent using soils collected from live and dead aspen and heterospecific Picea glauca (Moench) Voss in 24 stands across two ecosystems.
Methods
We conducted a greenhouse experiment using soils from 24 aspen stands. At each stand, we collected soil from three trees of each tree type and used live and sterilized versions of these soils to inoculate aspen seedlings. We then recorded mortality and growth of the seedlings over three months.
Results
Live inocula reduced aspen survival and growth relative to sterilized inocula, suggesting that pathogens drive PSF. Plant responses to live and dead aspen inocula were correlated across environments; however, responses to aspen and heterospecific Picea inocula were uncorrelated, suggesting that specialized pathogens may drive PSF.
Conclusions
Pathogen-driven negative PSFs can persist for multiple years irrespective of the environment, potentially limiting the regeneration of aspen stands following dieback. Persistent PSFs thus have potential to cause lagged effects on population and community dynamics.
... In our study, soil available P was highest in the native site, in correlation with a higher ECM fungal richness (Tables 1, 2). Few studies have investigated the role of ECM fungi for P uptake (Köhler et al., 2018;Queralt et al., 2019), but evidence showed that ECM-dominated stands can have easier access to organic P than AM-dominated forests (Albornoz et al., 2016;Rosling et al., 2016). Moreover, plants that form both AM and ECM associations can allocate C preferably to the fungal symbiont that provides more benefits relative to the abundance of readily available nutrients (Albornoz et al., 2016). ...
... Few studies have investigated the role of ECM fungi for P uptake (Köhler et al., 2018;Queralt et al., 2019), but evidence showed that ECM-dominated stands can have easier access to organic P than AM-dominated forests (Albornoz et al., 2016;Rosling et al., 2016). Moreover, plants that form both AM and ECM associations can allocate C preferably to the fungal symbiont that provides more benefits relative to the abundance of readily available nutrients (Albornoz et al., 2016). Therefore, P availability was likely not limiting in the native site, hence facilitating associations with a high diversity of ECM fungi for oak seedlings (Tedersoo and Bahram, 2019). ...
Competition for resources between arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) plants can alter belowground mycorrhizal communities, but few studies have investigated host effects on both AM and ECM communities. In Central Mexico, the AM plant Juniperus deppeana is frequently used for reforesting areas affected by soil erosion, while the surrounding native forests are dominated by ECM oak trees. Oaks are capable of associating with both AM and ECM fungi during part of their life cycle (a feature known as dual mycorrhization) but it is unclear whether junipers possess such ability. To assess how juniper planting may affect belowground fungal interactions with oaks, we investigated mycorrhizal associations in J. deppeana and Quercus rugosa seedlings along a disturbance gradient: a native oak forest, a mixed Juniperus-Quercus population in secondary vegetation and a juniper site severely degraded by mining extraction. We measured root colonization and identified fungal communities using soil and root meta-barcoding of the ITS2 rDNA region. ECM fungal community composition was strongly affected by disturbance (regardless of host), while the community composition of AM fungi was mostly host-dependent, with a higher AM fungal richness in J. deppeana . Importantly, the fungal communities associated with Q. rugosa seedlings significantly changed in the vicinity of juniper trees, while those of J. deppeana seedlings were not affected by the presence of oak trees. Even though ECM fungal richness was higher in Q. rugosa and in the native forest, we detected a variety of ECM fungi associated exclusively with J. deppeana seedlings, suggesting that this plant species may be colonized by ECM fungi. Our results indicate that J. deppeana can alter ECM native fungal communities, with implications for its use in reforestation of mixed oak forests.
... Mycorrhizae can enhance diversity and can reduce competitive inequalities between species (Johnson et al. 2004;Wagg et al. 2011;Sutherland et al. 2017). Hostile soil microorganisms may also aggravate or deteriorate the effects of competition (Bever 2015;Albornoz et al. 2016), depending on the plant species observed and the degree of their reactions to the soil microorganisms. However, in some studies, it is reported that soil microbial agents have no effect on plant competition (Casper and Castelli 2007), or that competition overwhelms the influence that soil microbes have on plant performance (Crawford and Knight 2017). ...
... Mycorrhizae can enhance diversity and can reduce competitive inequalities between species (Johnson et al. 2004;Wagg et al. 2011;Sutherland et al. 2017). Hostile soil microorganisms may also aggravate or deteriorate the effects of competition (Bever 2015;Albornoz et al. 2016), depending on the plant species observed and the degree of their reactions to the soil microorganisms. However, in some studies, it is reported that soil microbial agents have no effect on plant competition (Casper and Castelli 2007), or that competition overwhelms the influence that soil microbes have on plant performance (Crawford and Knight 2017). ...
... Mycorrhizae can enhance diversity and can reduce competitive inequalities between species (Johnson et al. 2004;Wagg et al. 2011;Sutherland et al. 2017). Hostile soil microorganisms may also aggravate or deteriorate the effects of competition (Bever 2015;Albornoz et al. 2016), depending on the plant species observed and the degree of their reactions to the soil microorganisms. However, in some studies, it is reported that soil microbial agents have no effect on plant competition (Casper and Castelli 2007), or that competition overwhelms the influence that soil microbes have on plant performance (Crawford and Knight 2017). ...
... Teste et al., (2020) suggest that in such cases the preference for a mycorrhizal type depends on a wide range of abiotic and biotic factors, including soil moisture and nutrient availability. When growing two dual-mycorrhizal tree species along a dune chronosequence in southwestern Australia, Albornoz et al., (2016) found the shift from AM to EM root colonization to be best explained by increasing soil age. However, it is still unclear how the mycorrhization rate of AM and EM depends on the biotic context, in particular on the presence of host species favoring either type of mycorrhiza. ...
• Recent studies found that the majority of shrub and tree species are associated with both arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) fungi. However, our knowledge on how different mycorrhizal types interact with each other is still limited. We asked whether the combination of hosts with a preferred association with either AM or EM fungi increases the host tree roots’ mycorrhization rate and affects AM and EM fungal richness and community composition.
• We established a tree diversity experiment, where five tree species of each of the two mycorrhiza types were planted in monocultures, two‐species and four‐species mixtures. We applied morphological assessment to estimate mycorrhization rates and next‐generation molecular sequencing to quantify mycobiont richness.
• Both the morphological and molecular assessment revealed dual‐mycorrhizal colonization in 79% and 100% of the samples, respectively. OTU community composition strongly differed between AM and EM trees. While host tree species richness did not affect mycorrhization rates, we observed significant effects of mixing AM‐ and EM‐associated hosts in AM mycorrhization rate. Glomeromycota richness was larger in monotypic AM tree combinations than in AM‐EM mixtures, pointing to a dilution or suppression effect of AM by EM trees. We found a strong match between morphological quantification of AM mycorrhization rate and Glomeromycota richness.
• Synthesis. We provide evidence that the combination of hosts differing in their preferred mycorrhiza association affects the host's fungal community composition, thus revealing important biotic interactions among trees and their associated fungi.
... In a study of edaphic effects on symbiosis during soil development, mycorrhizal colonization shifted from AM fungi to ECM fungi (the plants had both types of mycorrhizal association) in response to decreasing phosphorus content in the soil. Such a shift in mycorrhizal association enables the acquisition of organic phosphorus via extracellular phosphatase activity (Albornoz et al. 2016). ...
Land use change is one of the major causes of biodiversity loss, mostly due to habitat change and fragmentation. Belowground fungal diversity is very impor-tant in terrestrial ecosystems, however, the effect of land use change on soil fungal community is poorly understood. In this review, a total of 190 studies worldwide were analyzed. To monitor the effect of land use change, different fungal parameters such as richness, diversity, community composition, root colonization by arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi, spore density, ergosterol, and phospholipid fatty acid (PLFA) content and AM fungal glomalin related soil protein (GRSP) were studied. In general, results from analyzed studies often showed a negative response of fungal quantitative parameters after land use change from less-intensive site management to intensive site management. Land use change mostly showed significant shifts in fungal community composition. Considering land use change types, only 18 out of 91 land use change types were included in more than 10 studies, conversion of primary and secondary forest to various, more intensive land use was most often represented. All these 18 types of land use change influenced fungal community composition, however, the effects on quantitative parameters were mostly inconsistent. Current knowledge is not sufficient to conclude general land use impacts on soil fungi as the reviewed studies are fragmented and limited by the local context of land use change. Unification of the methodol-ogy, detailed descriptions of environmental factors, more reference sequences in public databases, and especially data on ecology and quantitative parameters of key fungal species would significantly improve the understanding of this issue.
