Soil Characteristics Driving Arbuscular Mycorrhizal Fungal Communities in Semiarid Mediterranean Soils

Abstract

We investigated communities of arbuscular mycorrhizal fungi (AMF) in the roots and the rhizosphere soil of Brachypodium retusum in six different natural soils under field conditions. We explored phylogenetic patterns of AMF composition using indicator species analyses to find AMF associated with a given habitat (root versus rhizosphere) or soil type. We tested whether the AMF characteristics of different habitats or contrasting soils were more closely related than expected by chance. Then we used principal-component analysis and multivariate analysis of variance to test for the relative contribution of each factor in explaining the variation in fungal community composition. Finally, we used redundancy analysis to identify the soil properties that significantly explained the differences in AMF communities across soil types. The results pointed out a tendency of AMF communities in roots to be closely related and different from those in the rhizosphere soil. The indicator species analyses revealed AMF associated with rhizosphere soil and the root habitat. Soil type also determined the distribution of AMF communities in soils, and this effect could not be attributed to a single soil characteristic, as at least three soil properties related to microbial activity, i.e., pH and levels of two micronutrients (Mn and Zn), played significant roles in triggering AMF populations. IMPORTANCECommunities of arbuscular mycorrhizal fungi (AMF) are main components of soil biota that can determine the productivity of ecosystems. These fungal assemblages vary across host plants and ecosystems, but the main ecological processes that shape the structures of these communities are still largely unknown. A field study in six different soil types from semiarid areas revealed that AMF communities are significantly influenced by habitat (soil versus roots) and soil type. In addition, three soil properties related to microbiological activity (i.e., pH and manganese and zinc levels) were the main factors triggering the distribution of AMF. These results contribute to a better understanding of the ecological factors that can shape AMF communities, an important soil microbial group that affects multiple ecosystem functions.A rbuscular mycorrhizal fungi (AMF) represent an important soil microbial group that affects multiple ecosystem functions and processes, including nutrient cycling, plant productivity and competition, and plant diversity. As a consequence, the number of ecological studies concerning AMF has increased considerably in recent years (1-9). Those studies considered AMF communities associated with different host plants in many different ecosystems. However, studies comparing the occurrence of specific AMF species and communities in different soil types are scarce and have focused mainly on cultivated soils and different land uses (10-13). Differences in soil types have been reported to be key factors determining AMF community composition (10), and this is particularly relevant in stressed environments such as serpentine soi...

Arbuscular Mycorrhizal Fungi Associated with Rice (Oryza sativa L.) in Ghana: Effect of Regional Locations and Soil Factors on Diversity and Community Assembly

“…Although the Northern, Brong-Ahafo, and Ashanti regions also showed high AP levels, under the agroecological zones, the GSZ was observed to possess the lowest level compared to the FSTZ and DFZ. In previous studies, it was demonstrated that the soil physiochemical properties affected the composition of AMF communities and influenced their distribution and performance in the agricultural environment [30,42,60,[75][76][77][78]. In the present study, the AMF communities based on the observed OTUs were affected independently by AP content and their interactions with other nitrogen source elements, such as NO 3 and C/N.…”

“…In several studies, the occurrence of AMF colonization in rice roots under different production regimes at diverse geographical locations demonstrated variable effects on the community compositions of AMF [26,[41][42][43]. Lumini et al [44] reported that AMF colonization in rice roots occurred only under dry conditions and not in the conventional paddy wet fields.…”

Tropical forest type influences community assembly processes in arbuscular mycorrhizal fungi

“…Several studies have previously reported how environmental filtering, that is soil properties and climatic variables are strong predictors of the AM fungal community assembly in natural environments (Alguacil, Torres, Montesinos‐Navarro, & Roldán, ; Bouffaud et al, ; Lekberg et al, ; Rodríguez‐Echeverría et al, ; Vályi, Mardhiah, Rillig, & Hempel, ). Our results confirm that the abiotic environment undoubtedly plays a key role in abundance and distribution of this group of micro‐organisms in rain forests, but other drivers than the environment alone should not be ignored.…”

The Future Prospects of Arbuscular Mycorrhizal Fungi in Slope Ecological Restoration

“…Inoculation with AMF would result in higher water availability due to the stronger water absorption of hypha and would make further efforts to restore the plant hydraulic status with higher soil drying rates [4,33,60]. Electrical conductivity, which has a positive correlation with soil moisture within a certain range, has also been found to have a clear correlation with AMF inoculation [63,64]. As for enzyme activities, though the impact mechanism is not yet clear, researchers have detected increases in β-glucosidase [63], catalase [45,63], urease [17], dehydrogenase [17], protease [17], peroxidas and dismutase [47], and phosphatase activities [17,63], and transient increases in catalase activity after AMF inoculation [17].…”

“…As for enzyme activities, though the impact mechanism is not yet clear, researchers have detected increases in β-glucosidase [63], catalase [45,63], urease [17], dehydrogenase [17], protease [17], peroxidas and dismutase [47], and phosphatase activities [17,63], and transient increases in catalase activity after AMF inoculation [17]. Studies also have shown a negative correlation between AMF and clay content [64], which may result in an increase in silt percentage. Those results may be due to more oxygen provided by soil with a high sand content, which can satisfy the oxygen requirement of AMF [65].…”