No abstract

The Guineo-Sudanian and Sudanian zones are home to predominantly ectomycorrhizal (EcM) plant communities dominated by members of the families Fabaceae (subfamily Ceasalpinioidae), Phyllanthaceae and Dipterocarpaceae. Numerous studies have shown that the aggregation of EcM trees is facilitated in part by the shared mycelial networks of EcM fungi. Mycelial networks involving mature trees would thus directly affect the survival of the seedlings of EcM trees and, thereby, the spatial structuring of the trees. In this study, we investigated the structure and spatial interactions of three vegetation types dominated by different EcM trees, namely, Isoberlinia doka, I. tomentosa and Uapaca togoensis. Three 50 m × 50 m plots were installed for each vegetation type. All EcM trees present in each plot were counted for estimation of density. Ripley's second order function K was used to estimate the spatial structure of EcMs trees. Spatial distribution of trees differed between species. Repulsion occurred at scales of 1 to 5 m between the different EcM trees species. By sharing nutrient through mycelial network, repulsion mechanisms observed during interaction between plants should have been cancelled but this was not observed in this study.

This study presents Paxilloboletus gen. nov., a new lamellate bolete genus represented by two tropical African species, Paxilloboletus africanus sp. nov. and Paxilloboletus latisporus sp. nov. Although the new taxa strongly resemble Paxillus (Paxillaceae), they lack clamp connections and form a separate generic clade within the Boletaceae phylogeny. The new species are lookalikes, morphologically only separable by their spore morphology. Descriptions and illustrations of the new genus and new species are given, as well as comments on ecology, distribution, and morphological differences with other gilled Boletaceae.

No abstract

Studies examining the role of abiotic variables on fructification sequences of ectomycorrhizal symbionts (boletes), the extent and direction of these effects are quite rare in Africa. In the current study, we assessed the effects of microclimate on the distribution and productivity of boletes in Benin. Nine permanent plots of 2500 m 2 each split into 25 subplots of 100 m 2 were installed in three different vegetation types. The first vegetation type is dominated by Isoberlinia doka, the second by Isoberlinia tomentosa and the third by Uapaca togoensis. Abiotic variables, including soil temperature, air temperature, air relative humidity and soil moisture, were recorded every 30 min from June to October. Each plot was surveyed twice a week during the mushroom season over 3 years (2015, 2016 and 2017) to record the abundance and the fresh biomass.The effects of microclimate on boletes productivity were evaluated using generalised linear mixed models in R. Boletes give the largest natural production in July and the lowest in October. Only soil moisture has a significant negative influence on the abundance (p > 0.05). The fruiting periods of boletes are known according to the variability of the microclimatic parameters and the vegetation.