Global negative effects of nutrient enrichment on arbuscular mycorrhizal fungi, plant diversity and ecosystem multifunctionality.

Despite widespread anthropogenic nutrient enrichment, it remains unclear how nutrient enrichment influences plant-arbuscular mycorrhizal fungi (AMF) symbiosis and ecosystem multifunctionality at the global scale. Here, we conducted a meta-analysis to examine the worldwide effects of nutrient enrichment on AMF and plant diversity and ecosystem multifunctionality using data of field experiments from 136 papers. Our analyses showed that nutrient addition simultaneously decreased AMF diversity and abundance belowground and plant diversity aboveground at the global scale. The decreases in AMF diversity and abundance associated with nutrient addition were more pronounced with increasing experimental duration, mean annual temperature (MAT) and mean annual precipitation (MAP). Nutrient addition-induced changes in soil pH and available phosphorus (P) predominantly regulated the responses of AMF diversity and abundance. Furthermore, AMF diversity correlated with ecosystem multifunctionality under nutrient addition worldwide. Our findings identify the negative effects of nutrient enrichment on AMF and plant diversity and suggest that AMF diversity is closely linked with ecosystem function. This study offers an important advancement in our understanding of plant-AMF interactions and their likely responses to ongoing global change.

Ma X ，Geng Q ，Zhang H ，Bian C ，Chen HYH ，Jiang D ，Xu X ... -  《-》

Arbuscular mycorrhizal fungi mitigate soil nitrogen and phosphorus losses: A meta-analysis.

Nutrient loss from terrestrial ecosystems via leaching and gaseous emissions is increasingly threatening global environmental and human health. Although arbuscular mycorrhizal fungi (AMF) have been shown to regulate soil N and P losses, a comprehensive quantitative overview of their influences on the losses of these soil nutrients across global scales is currently lacking. This study used a meta-analysis of 322 observations from 36 studies to assess the effect of AMF inoculum on 11 variables related to the loss of soil N and P. We found that the presence of AMF significantly reduced soil N and P losses, with the most pronounced reduction occurring in soil NO3--N (-32%), followed by total P (-21%), available P (-16%) and N2O (-10%). However, the mitigation effects of AMF on soil N and P loss were dependent on the identity of AMF inoculum, plant type and soil biotic and abiotic factors. Generally, the mitigation effects of AMF increased with increasing AMF root colonization rate, microbial diversity of inoculants, soil organic carbon (SOC) content and experimental duration as well as with decreasing soil sand contents and soil N and P availability. Overall, this meta-analysis highlights the importance of AMF inoculation in mitigating N and P nutrient loss and environmental pollution for terrestrial ecosystem sustainability.

Qiu Q ，Bender SF ，Mgelwa AS ，Hu Y ... -  《-》

Nutrient enrichment effects on mycorrhizal fungi in an Andean tropical montane Forest.

Delavaux CS ，Camenzind T ，Homeier J ，Jiménez-Paz R ，Ashton M ，Queenborough SA ... -  《-》

Suppression of Arbuscular Mycorrhizal Fungi Aggravates the Negative Interactive Effects of Warming and Nitrogen Addition on Soil Bacterial and Fungal Diversity and Community Composition.

Yang X ，Yuan M ，Guo J ，Shi L ，Zhang T ... -  《-》

Suppression of arbuscular mycorrhizal fungi decreases the temporal stability of community productivity under elevated temperature and nitrogen addition in a temperate meadow.

Global change alters how terrestrial ecosystems function and makes them less stable over time. Global change can also suppress the development and effectiveness of arbuscular mycorrhizal fungi (AMF). This is concerning, as AMF have been shown to alleviate the negative influence of global changes on plant growth and maintain species coexistence. However, how AMF and global change interact and influence community temporal stability remains poorly understood. Here, we conducted a 4-year field experiment and used structural equation modeling (SEM) to explore the influence of elevated temperature, nitrogen (N) addition and AMF suppression on community temporal stability (quantified as the ratio of the mean community productivity to its standard deviation) in a temperate meadow in northern China. We found that elevated temperature and AMF suppression independently decreased the community temporal stability but that N addition had no impact. Community temporal stability was mainly driven by elevated temperature, N addition and AMF suppression that modulated the dominant species stability; to a lesser extent by the elevated temperature and AMF suppression that modulated AMF richness associated with community asynchrony; and finally by the N addition and AMF suppression that modulated mycorrhizal colonization. In addition, although N addition, AMF suppression and elevated temperature plus AMF suppression reduced plant species richness, there was no evidence that changes in community temporal stability were linked to changes in plant richness. SEM further showed that elevated temperature, N addition and AMF suppression regulated community temporal stability by influencing both the temporal mean and variation in community productivity. Our results suggest that global environmental changes may have appreciable consequences for the stability of temperate meadows while also highlighting the role of belowground AMF status in the responses of plant community temporal stability to global change.

Yang X ，Mariotte P ，Guo J ，Hautier Y ，Zhang T ... -  《-》