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

Abstract

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.

Effects of arbuscular mycorrhizal fungi (amf) on Camellia sinensis (L.) o. kuntze under greenhouse conditions

“…Arbuscular mycorrhizal fungi (AMF) are considered as important components of agro ecosystems because of their potentiality to increase plant growth performance, improve soil-plant-water relations, enhance plant nutrient acquisition, resistance to disease and environmental stresses, improve soil quality, and productivity of the plants (Songachan, 2012). However, differences in AMF colonization rates relate to changes in the community composition of AMF and other variables such as the inoculum density, growth of roots, genetic compatibility between host plants and AMF, edaphic aspects and microbial activity (da Silva et al, 2017).…”

Succession stages and soil attributes influence the structure of arbuscular mycorrhizal fungi communities in the Atlantic Forest

“…As the morphological identification counts only the glomerospores to estimate the richness, the species that were in the non-sporulating phase are underestimated (Bartz et al 2008). Other studies based on morphological identification were able to access similar or higher percentages of estimated AMF species richness, between 70% and 77% in natural and cultivated areas (Pereira et al 2014), However, there are also reports of higher percentages: 80% of the estimated species in tropical coastal dunes (da Silva et al 2015b), 82% in natural and regenerating areas (Rodrigues et al 2021), between 85% and 93% in protected areas of the Atlantic Forest (Pereira et al 2018), and 98% in sandy coastal plain ecosystems of the Atlantic forest (da Silva et al 2017). This variation in the number of taxa is directly linked to the sampling effort.…”

“…Glomerospore density can be affected by soil attributes (da Silva et al 2017;Vieira et al 2020) and vegetation (Turrini et al 2018). In the present study, soils in areas undergoing initial regeneration were classified as sandy (dos , which are generally characterized by low nutrient availability, low water retention capacity and low levels of organic matter (Rocha et al 2021).…”

Freeze tolerance of poleward‐spreading mangrove species weakened by soil properties of resident salt marsh competitor

“…Two broad categories of mutualistic fungi that are often associated with plant-soil interactions are arbuscular mycorrhizae (AM) and dark septate endophytes (DSE). These fungi often aid plants by facilitating nutrient uptake (Barrow & Osuna, 2002;da Silva, da Silva, de Souza, Oehl, & Maia, 2017;Karasawa, Hodge, & Fitter, 2012) and may be particularly valuable symbionts in stressful environments (Singh, Gill, & Tuteja, 2011). Like AM fungi, DSE fungi can promote nutrient uptake and mitigate heat and drought stress in extreme environments (Jumpponen, 2001;Newsham, 2011;Ramirez-Viga et al, 2018), although the beneficial functions of DSE fungi are relatively understudied relative to those of AM fungi (Mandyam & Jumpponen, 2015).…”