Eliane Louisanna

French National Institute for Agriculture, Food, and Environment (INRAE) | INRAE · Ecologie des Forêts de Guyane (ECOFOG)

The determinants of phyllosphere microbial communities are drawing much attention given their functional importance for their plant host fitness and health. Identifying these determinants remains challenging in neotropical forests, considering the diversity of the tree hosts and the strong vertical heterogeneity of abiotic conditions within the can...

The biogeography of neotropical fungi remains poorly understood. Here, we reconstruct the origins and diversification of neotropical lineages in one of the largest clades of ectomycorrhizal fungi in the globally widespread family Russulaceae. We inferred a supertree of 3285 operational taxonomic units, representing worldwide internal transcribed sp...

Plant-associated microorganisms have been shown to aid plants in coping with drought. However, the underlying mechanisms are poorly understood and there is uncertainty regarding which microbial taxa and functions are mostly involved. We explored these issues in Neotropical rainforests and identified foliar microorganisms that may play a role in dro...

Heteroblastic variations among leaf traits is a well-known process, especially in bromeliad species that show abrupt changes, but little effort was directed to test whether comparable ontogenetic variation occurs among root traits and their fungal partners. Usually considered for their mechanical role, roots of bromeliads may also play a role in re...

Cross‐kingdom interactions with plants were frequently related to microbial pathogens and herbivores. Yet, mutualistic interactions that involve multiple partners can confer cross‐kingdom functional benefits, which have been understudied. Ant gardens (AGs) are recognized as one of the most sophisticated of all symbioses between ants and flowering p...

Urban expansion and associated habitat transformation drives shifts in biodiversity, with declines in taxonomic and functional diversity. Forests fragments within urban landscapes offer a number of ecosystem services, and help to maintain biodiversity and ecosystem functions. Here, we focus on a tropical forest environment, and on the soil biota. U...

Bromeliads represent a major component of neotropical forests and encompass a considerable diversity of life forms and nutritional modes. Bromeliads explore highly stressful habitats and root‐associated fungi may play a crucial role in this, but the driving factors and variations in root‐associated fungi remain largely unknown. We explored root‐ass...

The genus Phytophthora represents a group of plant pathogens with broad global distribution. The majority of them causes collar and root‐rot of diverse plant species. Little is known about Phytophthora communities in forest ecosystems, especially in Neotropical forests where natural enemies could maintain the huge plant diversity via negative densi...

The influence exerted by tree communities, topography, and soil chemistry on the assembly of macrofungal communities remains poorly understood, especially in highly diverse tropical forests. Here, we used a large dataset that combines inventories of macrofungal Basidiomycetes fruiting bodies, tree species composition, and measurements for 16 soil p...

In Amazonia, the knowledge about Fungi remains patchy and biased towards accessible sites. This is particularly the case in French Guiana where the existing collections have been confined to few coastal localities. Here, we aimed at filling the gaps of knowledge in undersampled areas of this region, particularly focusing on the Basidiomycota. From...

In bromeliads, nothing is known about the associations fungi form with seeds and seedling roots. We investigated whether fungal associations occur in the seeds and seedling roots of two epiphytic Aechmea species, and we explored whether substrate and fungal associations contribute to seed germination, and seedling survival and performance after the...

The patterns of the distribution of fungal species and their potential interactions with trees remain understudied in Neotropical rainforests, which harbor more than 16,000 tree species, mostly dominated by endomycorrhizal trees. Our hypothesis was that tree species shape the non-mycorrhizal fungal assemblages in soil and litter and that the divers...

Mechanical signals have an impact on plant development. Tropical rainforest trees display large variability for life–history traits related to biomechanics and therefore are a unique study system to better understand biomechanical trait variability from an evolutionary perspective. From sequences and gene expression data available in model species,...

We tested the response of seedlings of Dicorynia guianensis, a major timber tree species of French Guiana, to mycorrhizal symbiosis and water limitation in a semi-controlled experiment under natural light conditions. Under well-watered conditions, mycorrhizal colonization resulted in an increase of net photosynthesis, growth and phosphorus uptake....

• This work aimed at understanding the role of mycorrhizal status in phosphorus efficiency of tree seedlings in the tropical rainforest of French Guyana.• Mycorrhizal colonization, growth, phosphorus content, net photosynthesis and root respiration were determined on three occasions during a 9-month growth period for seedlings of two co-occurring s...

In French Guiana where soils are generally acidic and poor in inorganic nutrients, a characteristic feature of forests is the diversity of species. An ecological approach has shown that on the roots of the major forest species there is a prevalence of endomycorrhizae that have a particular intracellular structure (spiral hyphae). Their involvement...

The most probable number of arbuscular mycorrhizal (AM) fungal propagules, spore density and mycorrhizal colonization were studied in Dicorynia guianensis and Eperua falcata trees in three sites of the primary rain forest of French Guiana. A high number of propagules (17-230 per g soil) and number of spores (50-154 per g of soil) were found in the...

The influence of mycorrhizal infection rate and light environment on growth traits was examined for 50-week-old Dicorynia guianensis Amshoff tree seedlings. The seedlings were grown on two soil substrates (control and inoculated) in shade tunnels under three relative light levels (50%, 14% and 1% of full sunshine). For seedlings growing under 1% of...

Seedlings of Dicorynia guianensis Amshoff, an economically important timber tree species of the primary tropical rain forest of French Guiana, were grown in pots containing a disinfected soil inoculated or not with forest soil, mycorrhizal roots of D guianensis or nematodes. Plant growth parameters and root endomycorrhizal colonization were measure...