Interactions between mycorrhizal colonization and plant life forms along the successional gradient of coastal sand dunes in the eastern Mediterranean, Turkey

The mycorrhizal status of dune plant species in relation to their plant life forms was surveyed along a successional gradient of sand dune on the southern Mediterranean coast of Turkey. Roots of 64 dune plant species belonging to 30 families were collected from sand dune communities at four different successional stages: embryonic dunes (ED), mobile dunes (MD), fixed dunes (FD), and remnant dunes (RD). Of the plant species surveyed in all successional stages, 54 (84%) had formed mycorrhizal associations. Nonmycorrhizal plants with cryptophyte life forms predominated in the earlier successional stages (ED and MD), whereas the number and percent coverage of mycorrhizal plant species belonging to hemicryptophytes, phanerophytes, and chamaephytes generally increased with the stabilization of sand dunes. Arbuscular mycorrhizal (AM) colonization was found to be the dominant mycorrhizal type in ED, MD, and RD. But phanerophytes with dual colonization, AM and ectomycorrhizal, became the dominant life form with high plant coverage in the FD stage. Total percentage of mycorrhizal root length colonization showed significant positive correlations relating to soil parameters such as organic matter and nitrogen content, while negatively correlating to high soil reaction (pH).     

Arbuscular mycorrhizal fungal communities along a pedo-hydrological gradient in a Central Amazonian terra firme forest

Little attention has been paid to plant mutualistic interactions in the Amazon rainforest, and the general pattern of occurrence and diversity of arbuscular mycorrhizal fungi (AMF) in these ecosystems is largely unknown. This study investigated AMF communities through their spores in soil in a ‘terra firme forest’ in Central Amazonia. The contribution played by abiotic factors and plant host species identity in regulating the composition, abundance and diversity of such communities along a topographic gradient with different soils and hydrology was also evaluated. Forty-one spore morphotypes were observed with species belonging to the genera Glomus and Acaulospora, representing 44 % of the total taxa. Soil texture and moisture, together with host identity, were predominant factors responsible for shaping AMF communities along the pedo-hydrological gradient. However, the variability within AMF communities was largely associated with shifts in the relative abundance of spores rather than changes in species composition, confirming that common AMF species are widely distributed in plant communities and all plants recruited into the forest are likely to be exposed to the dominant sporulating AMF species.     

Diversity patterns of arbuscular mycorrhizal fungi associated with cacao in Venezuela

The arbuscular mycorrhizal fungal (AMF) communities associated with cacao in Venezuela were studied. The species of AMF spores present in sixteen cacao plantations and in one nursery were isolated and identified when possible. The spore densities, species richness, diversity, Shannon-Wiener diversity index and dominance concentration index for the AMF communities were calculated. Acaulospora scrobiculata was associated with cacao plants in all study sites. No Scutellospora spp. were found in the analyzed soils. The spore number found in cacao plantations was relatively lower as compared with other tropical crops (38 spores 100 g^–1 soil up to 1674). Soils that were cultivated with cacao for more than 40 years showed the lowest spore numbers. Species richness and diversity of AMF communities associated with cacao, were negatively correlated with available P in soils. The Shannon-Wiener diversity index was positively correlated with soil organic matter. These results indicate that the traditional cacao cultivation practices used in Venezuela, maintain mycorrhizal infection on cacao plants. The diversity of the AMF community is similar to that found in natural undisturbed ecosystems from Venezuela.     

Species richness and spore abundance of arbuscular mycorrhizal fungi across distinct land uses in Western Brazilian Amazon

Arbuscular mycorrhizal fungi (AMF) were surveyed for species richness and abundance in sporulation in six distinct land uses in the western Amazon region of Brazil. Areas included mature pristine forest and sites converted to pasture, crops, agroforestry, young and old secondary forest. A total of 61 AMF morphotypes were recovered and 30% of them could not be identified to known species. Fungal communities were dominated by Glomus species but Acaulospora species produced the most abundant sporulation. Acaulospora gedanensis cf., Acaulospora foveata, Acaulospora spinosa, Acaulospora tuberculata, Glomus corymbiforme, Glomus sp15, Scutellospora pellucida, and Archaeospora trappei sporulated in all land use areas. Total spore numbers were highly variable among land uses. Mean species richness in crop, agroforestry, young and old secondary forest sites was twice that in pristine forest and pasture. fungal communities were dominated in all land use areas except young secondary forest by two or three species which accounted for 48% to 63% of all sporulation. Land uses influenced AMF community in (1) frequency of occurrence of sporulating AMF species, (2) mean species diversity, and (3) relative spore abundance. Conversion of pristine forest into distinct land uses does not appear to reduce AMF diversity. Cultural practices adopted in this region maintain a high diversity of arbuscular mycorrhizal fungi.     

Arbuscular mycorrhizal fungal diversity in phosphorus-deficient Alfisols of a dry North-western agro-ecosystem of Tamil Nadu,India

Semi-arid tropical soils, characterized by low soil organic carbon (SOC) with limited available macronutrients and micronutrients for crop plants, are predicated to have a yield sustainability problem in the future due to intensive cropping and limited nutrient management adoptions. Arbuscular mycorrhizal fungi (AMF), the functional link between plant and soil, play a pivotal role in nutrient cycling, organic matter stabilization and soil structure and fertility improvement. Hence, so far unexplored or underutilized, native AMF could be a potential resource for fertility management of these semi-arid tropical soils. Hence, in the present investigation, we assessed the abundance and diversity of AMF in phosphorus-deficient agricultural soils of semi-arid tropics of southern India. Our results show that the spore density and infective propagules of AMF were relatively low in these soils. The morpho-typing of extracted AMF spores revealed that these soils were dominated by glomeraceae (six species of Glomus) while species of Gigaspora, Scutellospora and Acaulospora were found in low abundance. The diversity indices assessed for the AMF species were also globally low. The non-metric multi-dimensional scaling and hierarchical cluster analysis of species richness showed variation in the community composition of AMF in the soils. The principal component analysis of the assessed soil variables suggest that the available phosphorus (P), SOC and dehydrogenase and alkaline phosphatase activities had negative impact on spore density and infective propagules of AMF with no effect on species diversity. The regression analyses reveal that the available P is the significant soil variable that drives the AMF abundance and infectivity. This study opens the possibilities of effective utilization of native mycorrhizae for agriculture in semi-arid tropical soils.     

Effect of the spatial and seasonal soil heterogeneity over arbuscular mycorrhizal fungal spore abundance in the semi-arid valley of Tehuacán-Cuicatlán, Mexico

Recent studies have shown that some species of Mimosa (Leguminosae-Mimosoideae) create resource islands (RI), rich in soil organic matter and nutrients, as well as in arbuscular mycorrhyzal fungal (AMF) spores, in the semi-arid Valley of Tehuacán-Cuicatlán. The relevance of this fact is that arid and semi-arid regions are characterized by low fertility soils and scarce precipitation, limiting plant species growth and development; this explains why the presence of AM fungi may be advantageous for mycorrhizal desert plants. Fluctuations in AMF spore numbers could be related to environmental, seasonal and soil factors which affect AMF sporulation, in addition to the life history of the host plant. The aim of this study was to asses the impact of spatial (resource islands vs open areas, OA) and seasonal (wet season vs start of dry season vs dry season) soil heterogeneity in the distribution and abundance of AMF spores in four different study sites within the Valley. We registered AMF spores in the 120 soil samples examined. Significant differences in the number of AMF spores were reported in the soil below the canopy of Mimosa species (RI) comparing with OA (RI > OA), and between Mimosa RI themselves when comparing along a soil gradient within the RI (soil near the trunk > soil below the middle of the canopy > soil in the margin of the canopy > OA); however, there were no significant differences between the soil closest to the trunk vs middle, and margin 's OA. Finally, more spores were reported in the soil collected during the wet season than during the dry season (wet > start of dry > dry). Therefore, the distribution of AMF spores is affected by spatial and seasonal soil heterogeneity. This study points out the relevance of Mimosa RI as AMF spore reservoirs and the potential importance of AM fungi for plant species survivorship and establishment in semi-arid regions. AM fungi have recently been recognized as an important factor determining plant species diversity in arid and temperate ecosystems.     

Terrestrial vertebrates promote arbuscular mycorrhizal fungal diversity and inoculum potential in a rain forest soil

We examined whether terrestrial vertebrates affected the arbuscular mycorrhizal fungal spore communities and mycorrhizal inoculum potential (MIP) of a tropical rain forest soil by comparing plots where terrestrial vertebrates had been excluded for 3 years to adjacent control plots. We extracted spores from soil using sucrose density gradient centrifugation and assayed MIP by growing seedlings of maize ( Zea mays ) and a rain forest tree ( Flindersia brayleana ) in intact soil cores from exclosure and control plots. Control plots had significantly higher spore abundance, species richness and diversity than exclosures. Spore community composition also differed significantly between exclosure and control plots. Seedlings of both plant species grown in control cores had significantly higher arbuscular-mycorrhizal colonization than those grown in exclosure cores. This study suggests that loss of vertebrates could alter rates of mycorrhizal colonization with consequences for community and ecosystem properties.     

Community structure of arbuscular mycorrhizal fungi in a primary successional volcanic desert on the southeast slope of Mount Fuji

Community structure of arbuscular mycorrhizal fungi (AMF), evaluated as spore samples and mycorrhizal roots of four herbaceous plant species, was investigated at different altitudes in a primary successional volcanic desert on Mount Fuji using molecular methods (fragment and sequence analysis of the large ribosomal subunit RNA gene). In total, 17 different AMF clades were identified, and most were members of the Glomaceae, Acaulosporaceae, and Gigasporaceae. The AMF community structures detected by spore sampling were inconsistent with those from plant roots. Of all AMF clades, six (35.3%) were detected only on the basis of spores, six (35.3%) only in roots, and five corresponded to both spores and roots (29.4%). Although an Acaulospora species was the most dominant among spores (67.1%), it accounted for only 6.8% in root samples. A species analysis of AMF communities at different altitudes demonstrated that AMF species diversity increased as altitude decreased and that the species enrichment at lower altitudes resulted from the addition of new species rather than species replacement. The inconsistencies in the species composition of spore communities with those in roots and the change in species diversity with altitude are discussed.     

Glomus intraradices dominates arbuscular mycorrhizal communities in a heavy textured agricultural soil

Arbuscular mycorrhizal fungal (AMF) spore communities were surveyed in a long-term field fertilization experiment in Switzerland, where different amounts of phosphorus (P) were applied to soil. Plots receiving no P as well as plots systematically fertilized in excess to plant needs for 31 years were used to test the hypothesis that application of P fertilizer changes the composition and diversity of AMF communities. AMF spores were isolated from the field soil, identified, and counted so as to quantify the effect of P fertilization on AMF spore density, composition, and diversity. Trap cultures were established from field soil with four host plants (sunflower, leek, maize, and Crotalaria grahamiana), and the spore communities were then analyzed in substrate samples from the pots. Altogether, nine AMF species were detected in the soil. No evidence has been acquired for effect of P fertilization on spore density, composition, and diversity of AMF in both the field soil and in trap cultures. On the other hand, we observed strong effect of crop plant species on spore densities in the soil, the values being lowest under rapeseed and highest under Phacelia tanacetifolia covercrop. The identity of plant species in trap pots also significantly affected composition and diversity of associated AMF communities, probably due to preferential establishment of symbiosis between certain plant and AMF species. AMF spore communities under mycorrhizal host plants (wheat and Phacelia in the fields and four host plant species in trap pots) were dominated by a single AMF species, Glomus intraradices. This resulted in exceptionally low AMF spore diversity that seems to be linked to high clay content of the soil.Electronic supplementary material Supplementary material is available for this article at and accessible for authorised users.     

Community analysis of arbuscular mycorrhizal fungi associated with Ammophila arenaria in Dutch coastal sand dunes

A polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) approach for the detection and characterization of arbuscular mycorrhizal fungi (AMF) 18S ribosomal DNA (rDNA) was developed and applied to the study of AMF communities associated with the main sand-stabilizing plant species of the Dutch sand dunes, marram grass (Ammophila arenaria, L.). DNA was extracted directly from plant roots, soil or isolated AMF spores, and prominent bands resulting from AMF-specific DGGE profiles were excised for sequence analysis. This strategy provided a robust means of detecting and identifying AMF-like species without the use of trap plant cultivation methods. A number of Glomus-like and Scutellospora-like sequences was detected, including a putatively novel Glomus species, and differences were observed in the dominant AMF-like populations detected in healthy vs. degenerating stands of A. arenaria and in bulk sand dune soil. It has previously been suggested that plant pathogens, such as fungi and nematodes, may contribute to the decline of A. arenaria. Although no causal relationship can be drawn between the observed differences in the dominantly detected AMF-like populations and the vitality of plant growth, these results indicate that mutualistic interactions between this plant and AMF should not be overlooked when examining the role of soil-borne microorganisms in vegetation dynamics. In addition, there were discrepancies observed between the AMF-like groups detected in spore populations vs. direct 18S rDNA analysis of root material, corroborating previous suggestions that spore inspection alone may poorly represent actual AMF population structure.     

Ecological Assessment of Dune Restorations in the Great Lakes Region

Because of the economic and environmental importance of stabilizing fragile sand dune habitats, restoration of dunes has become a common practice. Restoration efforts in the Great Lakes and East Coast regions of North America often consist of planting monocultures of the dominant native grass species, Ammophila breviligulata. We evaluated 18 dune restoration projects in the Great Lakes region conducted over the past 25 years. We characterized attributes of diversity (plants and insects), vegetation structure (plant biomass and cover), and ecological processes (soil nutrients and mycorrhizal fungi abundance) in each restoration, and we compared these measures to geographically paired natural dune communities. Restoration sites were similar to reference sites in most measured variables. Differences between restorations and reference sites were mostly explained by differences in ages, with the younger sites supporting slightly lower plant diversity and mycorrhizal spore abundance than older sites. Plant community composition varied little between restored and reference sites, with only one native forb species, Artemisia campestris, occurring significantly more often in reference sites than restored sites. Although it remains unclear whether more diverse restoration plantings could accelerate convergence on the ecological conditions of reference dunes, in general, traditional restoration efforts involving monoculture plantings of A. breviligulata in Great Lakes sand dunes appear to achieve ecological conditions found in reference dunes.     

Effects of long-term NP-fertilization on abundance and diversity of arbuscular mycorrhizal fungi under a maize cropping system

Diversity of arbuscular mycorrhizal fungi (AMF) in 27-year long-term NP-fertilization plots under a maize cropping system in Thailand was studied through spore morphological characterization. The plots received 0–0, 60–60, 120–120 and 180–180 kg N-P₂O₅ ha^–1 year^–1 as ammonium sulfate and triple superphosphate. The plots were sampled monthly for one year, the AMF spores were counted and morphotyped, and taxa were identified after morphotyping and monospecific pot culture. Spore number g^–1 soil, relative spore abundance and Shannon-Wiener indexes were calculated. Sixteen putative taxa were recorded from the field of which nine sporulated on maize roots in pot culture. The long-term fertilization caused decreases in AMF total spore numbers and variation in species diversity depended on sampling time. Effects of fertilization on spore number and also relative spore abundance varied with species and sampling time. Among the nine species sporulating under maize, only Acaulospora sp.1 showed no change (P > 0.003 after Bonferroni correction) in spore number with fertilization in the field; and was therefore classified as an AMF species insensitive to fertilization. Spores of Entrophospora schenckii, Glomus mosseae, Glomus sp.1, Glomus geosporum-like and Scutellospora fulgida, though they decreased in absolute numbers in response to fertilization, showed no change (P > 0.003 after Bonferroni correction) in relative abundance; these species were classified as AMF species slightly sensitive to fertilization. Three unidentified species of Glomus, though they decreased in absolute numbers in response to fertilization, showed decreases (P < 0.003 after Bonferroni correction) in relative abundance; these species were classified as AMF species highly sensitive to fertilization.     

Changes in arbuscular mycorrhizal fungal communities along a river delta island in northeastern Brazil

Arbuscular mycorrhizal fungi (AMF) play a key role in the maintenance of the balance of terrestrial ecosystems, but little is known about the biogeography of these fungi, especially on tropical islands. This study aims to compare AMF community structure along a transect crossing a fluvial-marine island and relate these communities with soil and vegetation parameters to shed light on the forces driving AMF community structure on a local scale. We tested the hypothesis that the composition of AMF communities changes across the island, even within short distances among sites, in response to differences in edaphic characteristics and vegetation physiognomies. We sampled roots and soils in five different natural and degraded habitats: preserved mangrove forest (MF), degraded mangrove forest (MD), natural Restinga forest (RF), and two regeneration Restinga forests (RR1 and RR2) on Ilha da Restinga, northeastern Brazil. We determined the mycorrhizal colonization rate and AMF community structure based on morphological spore identification. The island soils were sandy with pH varying from acid to neutral; higher levels of organic matter were registered in RF and lower in MF; other chemical and physical soil attributes differed along the habitat types on the island. In total, 22 AMF species were identified, without any difference in species richness. However, the diversity and composition of AMF communities, spore abundance per families, and mycorrhizal colonization were statistically different among the habitats. The composition of AMF communities was strongly related to soil characteristics, especially the sum of exchangeable bases. Our results indicate that the different habitat types have diverse AMF communities even within short distances among habitats. In conclusion, islands with high spatial heterogeneity in soil parameters and diverse vegetation are potential refuges for the diversity conservation of AM fungi.     

Glomeromycotan mycorrhizal fungi from tropical Australia III. Measuring diversity in natural and disturbed habitats

Aims and Background

The aim was to investigate the diversity and distribution of Glomeromycotan fungi forming arbuscular mycorrhizal associations (AMF) in undisturbed and disturbed habitats in the vicinity of Kakadu National Park in tropical Australia. This is a tropical region with a 7–9 month dry season and a monsoonal wet season. Complimentary methods of fungus detection were used to investigate the diversity and relative dominance of AMF at a regional scale.

Methods

Soils were sampled from 32 sites, representing eucalypt savanna woodlands, wetlands, sandstone escarpment, rainforest, and disturbed mine waste rock dumps (overburden or spoil). Populations of AMF were identified and quantified using spores from soil. Morphology patterns of fungi colonising bait plant roots were examined and isolates were obtained by four complimentary pot-culturing methods.

Results

Different methods of detecting fungi produced different answers about which AMF were most important in the tested soils. In particular, spore surveys apparently underestimated the importance of Glomus species and overestimated the activity of Acaulospora species with numerous small spores, while calculated spore biovolumes overestimated the importance of Scutellospora and Gigaspora species with large spores, relative to inoculum levels of these fungus categories measured in bioassays. Spore surveys revealed 15 species of fungi and 8 additional fungi were recovered from the same soil samples using pot-culture isolation methods. Pot-cultures were especially important for detecting Glomus species that had high inoculum levels, but rarely produced spores in soils. Spores of AMF increased in abundance as vegetation developed in mine habitats reaching a peak that was higher than in undisturbed plant communities. Spore numbers (but not biovolumes) were well correlated with bioassay measurements of inoculum levels.

Conclusions

Most AMF species were widespread, but several were restricted to disturbed habitats or wetland soils. Undisturbed sites had a substantially higher diversity of AMF than partially vegetated mine waste rock dumps. It is recommended that AMF population surveys should not be based entirely on spore occurrence data, to avoid overlooking important fungi that sporulate infrequently. These fungi could be detected by bioassays or pot culture isolation from soil. Major variations in the detectability of AMF correspond to different life history strategies and can mask variations in their abundance.     

Diversity of AMF associated with Ammophila arenaria ssp. arundinacea in Portuguese sand dunes

Dune vegetation is essential for the formation and preservation of sand dunes and the protection of the coast line. Coastal sand dunes are harsh environments where arbuscular mycorrhizal fungi (AMF) play an important role in promoting plant establishment and growth. We present a study of the diversity of AMF associated with A. arenaria ssp. arundinacea in two locations of the Portuguese coast under a Mediterranean climate. These two locations were selected to compare a well-preserved dune system from a protected area with a degraded dune system from a public beach. AMF diversity was assessed mainly by cloning and sequencing of a fragment of the ribosomal SSU using the primer NS31 and AM1. Most of the 89 AMF clones obtained from the rhizosphere and roots of A. arenaria belonged to the genus Glomus, the largest clade within the Glomeromycota. Higher AMF diversity was found in the least disturbed site, in which spores of Scutellospora persica, Glomus constrictum and Glomus globiferum were found in the rhizosphere of A. arenaria.     

Differences in the species composition of arbuscular mycorrhizal fungi in spore, root and soil communities in a grassland ecosystem

Most studies on the species composition of arbuscular mycorrhizal fungi (AMF) have solely analysed mycorrhizal roots or AM spores collected from soil samples. However, the spore production rate and proportions of AMF mycelium in roots and soils have all been shown to vary substantially in a taxon-specific manner. Therefore, in the study presented here we used a molecular approach to analyse the species composition of AMF in spores, intra-radical and extra-radical mycelium in an intensively farmed meadow in central Germany. By polymerase chain reaction and sequencing of the ITS region members of seven different families and species groups within Glomeromycota were identified. The data revealed remarkable differences in the composition of AMF taxa both between the spores and the mycelia, and between the two types of mycelia. Glomus group Ab was dominant in roots and spores, in accordance with previous research. However, members of this group were rarely detected as extra-radical mycelium, in which Paraglomeraceae were dominant, although we found no evidence for the presence of Paraglomeraceae in roots or spores, even when a specific primer set was used. These results may be interpreted as a further indication that AMF are not necessarily obligate symbionts of plants.     

Mycorrhizae and succession in plantings of beachgrass in sand dunes

A survey of arbuscular mycorrhizal fungi (AMF), arbuscular mycorrhizae (AM), and hyphal networks of AMF was carried out in sand dune sites of different successional stages in the Province Lands Area of Cape Cod National Seashore, Massachusetts. The study focused on large-scale plantings (each of 12–20 ha) of American beachgrass (Ammophila breviligulata) aged 0–7 yr and five adjacent natural dune areas. Sample sites ranged in vegetative cover from barren to forested. Spores of 17 species of AMF were recovered from the dunes. Over the successional sequence, there were increases in the richness and spore populations of the AMF community, the extent of colonization of A. breviligulata roots, and the mycorrhizal inoculum potential of the soil. Unvegetated sites lacked propagules of AMF, but roots of planted culms of A. breviligulata (which carried propagules of AMF) became mycorrhizal in <1 yr after planting. Spores were recovered from previously AMF-free sites that had been planted with beachgrass for 47 wk, and five species of AMF sporulated in sites <6 yr old. Significant hyphal networks were not present in any of the planted areas (<6 yr old at the time of sampling), but did occur in natural areas. The rate of invasion of areas planted to A. breviligulata by later successional plant species may in part depend upon the establishment of a vigorous network of hyphae of AMF in a site.     

Taxonomic diversity and community structure of arbuscular mycorrhizal fungi (Phylum Glomeromycota) in three maritime sand dunes in Santa Catarina state,south Brazil

Community structure and species richness of arbuscular mycorrhizal fungi (Phylum Glomeromycota) were studied in sand dune sites at Itapiruba (southern), Joaquina (intermediate) and Praia Grande (northern) beaches along the coast of the state of Santa Catarina, Brazil. In each site, a 20 × 20 m plot was established and 20 soil samples collected in a regular grid pattern. Fungal spores were extracted from each sample, counted and identified to species level. A total of 25 species were recovered belonging to seven genera and five families in the Glomeromycota. Gigaspora albida and Acaulospora scrobiculata occurred in >50 % of samples at all three sites. Other common species whose sample frequency was >50 % in one or two sites were Scutellospora weresubiae, Scutellospora cerradensis and Racocetra gregaria, while the remaining majority of species were detected in <25 % of samples within a given site. Dune sites could be differentiated based on the higher frequency of occurrence of S. cerradensis and Acaulospora morrowiae in Itapiruba, S. weresubiae in Joaquina, and Scutellospora hawaiiensis in Praia Grande. No differences across sites were observed for species richness and total spore numbers, the latter averaging from 28.8 to 31.8 spores per 100 ml soil. Shannon diversity was significantly higher in Praia Grande compared to the other two sites. Differences in the relative spore abundance of genera among dunes were detected only for Scutellospora, which was significantly more abundant in the Joaquina beach. Community structure, as depicted by species rank/log abundance graphs, was not significantly different between areas according to the Kolmogorov–Smirnov two-sample test. Species accumulation curves demonstrated that 13 samples were enough to detect 90 % of all species. Overall, sand dune systems share similar arbuscular mycorrhizal fungal communities despite being geographically distant (150 km) from each other.     

Arbuscular mycorrhizal fungal diversity in tropical sand dune and restinga at Peró Beach in Rio de Janeiro state,Brazil

The diversity of arbuscular mycorrhizal fungi (sub-phylum Glomeromycotina) in two contrasting coastal ecosystems (dunes and restinga) at Peró Beach, Rio de Janeiro state, Brazil was evaluated at the end of the rainy (May) and dry (November) seasons, in 2014. A total of 22 species belonging to ten genera and five families were recorded. Glomus macrocarpum and Rhizoglomus microaggregatum had large biomass and frequencies of glomerospores at both sites. Glomerospore abundance was higher in the dry season in dunes and in the rainy season in restinga. Redundancy analysis revealed significant relationships between AMF-physical and chemical soil parameters. Shannon's index and Pielou's evenness indicated greater AMF diversity in dunes than restinga, despite the lower number of glomerospores in dunes. These results highlight the importance of knowing the AMF communities in different coastal ecosystems, especially in dunes, which due to the low vegetation cover are most frequently impacted by anthropic actions.     

Effects of environmental and temporal factors on Glomeromycotina spores in sand dunes along the Gulf of Valencia (Spain)

AMF symbiosis in sand dunes is the key for maintenance of stable vegetation. The main goal of this work was to determine the effects of environmental and temporal factors on AMF living in sand dunes (Gulf of Valencia, Spain). Soil samples were collected seasonally at 6 sites, during 2 yrs, from three habitats and four plant species and the frequency and relative abundance of AMF was examined. AMF were more frequent in mobile than in embryonic dunes, in spring and in sites with old vegetation. Ten AMF species were identified, their distribution depending mainly on the anthropogenic disturbance of the site. Gigasporaceae Cetraspora sp. and Dentiscutata sp. preferred undisturbed soil whereas Diversisporaceae, Glomeraceae and other Gigasporaceae were associated with recently restored soils. All AMF species were found in all plant species although Corymbiglomus corymbiforme was mainly associated with Echinophora spinosa. Our results might be of help for Mediterranean sand dune restoration.