Arbuscular mycorrhizal fungi alleviate phosphorus limitation by reducing plant N:P ratios under warming and nitrogen addition in a temperate meadow ecosystem

Zhang

et al. 2021

Oikos

Nutrient enrichment can reduce ecosystem stability, typically measured as temporal stability of a single function, e.g. plant productivity. Moreover, nutrient enrichment can alter plant–soil interactions (e.g. mycorrhizal symbiosis) that determine plant community composition and productivity. Thus, it is likely that nutrient enrichment and interactions between plants and their soil communities co‐determine the stability in plant community composition and productivity. Yet our understanding as to how nutrient enrichment affects multiple facets of ecosystem stability, such as functional and compositional stability, and the role of above–belowground interactions are still lacking. We tested how mycorrhizal suppression and phosphorus (P) addition influenced multiple facets of ecosystem stability in a three‐year field study in a temperate steppe. Here we focused on the functional and compositional stability of plant community; functional stability is the temporal community variance in primary productivity; compositional stability is represented by compositional resistance, turnover, species extinction and invasion. Community variance was partitioned into population variance defined as community productivity weighted average of the species temporal variance in performance, and species synchrony defined as the degree of temporal positive covariation among species. Compared to treatments with mycorrhizal suppression, the intact AM fungal communities reduced community variance in primary productivity by reducing species synchrony at high levels of P addition. Species synchrony and population variance were linearly associated with community variance with the intact AM fungal communities, while these relationships were decoupled or weakened by mycorrhizal suppression. The intact AM fungal communities promoted the compositional resistance of plant communities by reducing compositional turnover, but this effect was suppressed by P addition. P addition increased the number of species extinctions and thus promoted compositional turnover. Our study shows P addition and AM fungal communities can jointly and independently modify the various components of ecosystem stability in terms of plant community productivity and composition.

Section: Methodssupporting

confidence: 75%

Section: Discussionmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mycorrhizal suppression and phosphorus addition influence the stability of plant community composition and function in a temperate steppe

Zhang

et al. 2021

Oikos

“…Similarly, N‐induced changes in microbial community composition and physiology can help ecosystems adapt to P limitation (Jakobsen, Abbott, & Robson, 1992; Johnson et al., 2010; Tedersoo & Bahram, 2019; Wei et al., 2013). For example, arbuscular mycorrhizal fungi symbionts enhanced soil available P content, stimulated plant P absorption, and decreased the plant N:P ratio with N loading, which could help alleviate N‐induced P limitation over time (Mei, Yang, Zhang, Zhang, & Guo, 2019; Wang et al., 2018). However, it should be noted that responses of arbuscular mycorrhizae are ecosystem specific (Cusack et al., 2016; Sekaran, McCoy, Kumar, & Subramanian, 2019; Treseder, 2008; Wang et al., 2018), and that N loading typically decreases the abundance of arbuscular mycorrhizae (Treseder, 2004).…”

Section: Discussionmentioning

confidence: 99%

Long‐term nitrogen loading alleviates phosphorus limitation in terrestrial ecosystems

Chen

Groenigen

Hungate

et al. 2020

Global Change Biology

133

Increased human-derived nitrogen (N) deposition to terrestrial ecosystems has resulted in widespread phosphorus (P) limitation of net primary productivity. However, it remains unclear if and how N-induced P limitation varies over time. Soil extracellular phosphatases catalyze the hydrolysis of P from soil organic matter, an important adaptive mechanism for ecosystems to cope with N-induced P limitation. Here we show, using a meta-analysis of 140 studies and 668 observations worldwide, that N stimulation of soil phosphatase activity diminishes over time. Whereas short-term N loading (≤5 years) significantly increased soil phosphatase activity by 28%, long-term N loading had no significant effect. Nitrogen loading did not affect soil available P and total P content in either short-or long-term studies. Together, these results suggest that N-induced P limitation in ecosystems is alleviated in the long-term through the initial stimulation of soil phosphatase activity, thereby securing P supply to support plant growth. Our results suggest that increases in terrestrial carbon uptake due to ongoing anthropogenic N loading may be greater than previously thought.

“…Moreover, a small amount of evidence from greenhouse experiments has shown that AM fungi can reduce the negative effects of nitrogen enrichment on plant species diversity (van der Heijden Verkade, & de Bruin, ; Zhang et al, ), and the interactions between AM fungi and soil N play a key role in plant community composition (Johnson Rowland, Corkidi, Egerton‐Warburton, & Allen, ). N enrichment could induce phosphorus (P) limitation (Mei, Yang, Zhang, Zhang, & Guo, ), alter the N:P ratio, and affect mycorrhizal associations (Johnson Rowland, Corkidi, Egerton‐Warburton, & Allen, 2003; Johnson, ; Johnson, Wilson, Wilson, Miller, & Bowker, ). Nevertheless, whether AM fungi can alleviate the decline in grassland ecosystem function caused by N deposition and enhance grassland stability (e.g., increase carbon sequestration, accelerate litter decomposition, reduce greenhouse gas emissions, and increase plant species diversity and productivity) has not been explored adequately in the field.…”

Section: Introductionmentioning

confidence: 99%

Arbuscular mycorrhizal fungi alleviate the negative effect of nitrogen deposition on ecosystem functions in meadow grassland

et al. 2019

Self Cite

Nitrogen (N) deposition can reduce plant species richness and cause grassland degradation, thus affecting grassland ecosystem stability. Arbuscular mycorrhizal (AM) fungi play an important role in ecosystem stability. However, the influences of AM fungi on grassland ecosystem stability under N deposition remain unclear. We need more information on the impacts of N accumulation on the interactions between AM fungi and the plant community. To test the contribution of AM fungi to grassland stability under N deposition, a 5‐year field experiment was conducted in a temperate meadow with two manipulated factors, namely, N addition and AM fungi suppression. The plant species richness and diversity, biomass stability, litter decomposition, and greenhouse gas emissions were quantified. Under N addition, AM fungi did not affect the plant species diversity and richness but altered the coverages of different functional groups and increased the aboveground productivity and biomass stability. Litter decomposition increased under N addition and increased more in the treatment where AM fungi were not suppressed. The emissions of N2O and CH4 in the AM fungi suppression treatment were much higher than those in the nonsuppression treatment under N addition. Our results suggest that AM fungi can alter the plant community structure, increase plant productivity and community biomass stability, accelerate litter decomposition, and reduce the soil total N concentration and emissions of N2O and CH4 under N addition. Our results highlight that the conservation of AM fungi should be considered to alleviate grassland degradation and maintain grassland ecosystem multifunctionality in the future considering global change.