Communities of anamorphic fungi on green leaves and leaf litter of native forests of Scutia buxifolia and Celtis tala: Composition, diversity, seasonality and substrate specificity / Comunidades de hongos anamórficos en hojas verdes y hojarasca de bosques nativos deScutia buxifolia y Celtis tala: composición, diversidad, estacionalidad y especificidad del sustrato

Background: Xeric forests dominated by two tree species, Scutia buxifolia (Rhamnaceae) and Celtis tala (Ulmacea), are temperate, semi-deciduous wooded communities that represent the most abundant woodlands on the eastern plains of Buenos Aires Province, Argentina. The district of Magdalena has one of the most well-preserved native-forest areas, with an environmental heterogeneity that gives rise to the wide variability in the vegetation present. Aims: The aim of this study was to analyze the species composition, diversity, seasonal variations, and substrate specificity of anamorphic fungi (Ascomycota) on the green leaves and in the leaf litter of native forests dominated by Scutia buxifolia and Celtis tala from Magdalena, Buenos Aires, Argentina. Methods: In order to obtain the mycobiota of decomposition, seasonal samples of green leaves and leaf litter from both types of trees were collected over a two-year period. In the laboratory, the leaves were placed in a moist chamber and incubated at room temperature. Results: A total of 100 species of anamorphic Ascomycota were identified in both forests. No significant variations were observed in the richness, diversity, or evenness of the fungal communities of the green leaves and leaf litter of both forests between seasons. Conclusions: The species that characterized the fungal communities in the leaves of each of the trees were found to be different. The type of substrate had a stronger influence in determining the composition of the fungal community in both types of forests (AU)

Antecedentes: Los bosques xerófilos dominados por las especies arbóreas Scutia buxifolia (Rhamnaceae) y Celtis tala (Ulmaceae) conforman comunidades boscosas semicaducas y templadas que constituyen los bosques nativos más abundantes de la provincia de Buenos Aires, Argentina. En el distrito de Magdalena constituyen una de las comunidades naturales de este tipo mejor conservada, con una heterogeneidad ambiental que da lugar a la gran variabilidad en la composición de la vegetación presente. Objetivos: El objetivo del presente trabajo fue analizar las distribución de especies, la diversidad, las variaciones estacionales y la especificidad por el sustrato de hongos anamórficos (Ascomycota) presentes en las hojas verdes y en la hojarasca de los bosques nativos xerófilos dominados por las especies arbóreas Scutia buxifolia y Celtis tala en el partido de Magdalena, provincia de Buenos Aires, Argentina. Métodos: Para obtener la micobiota descomponedora se tomaron muestras estacionales de hojas verdes y hojarasca de los 2 tipos de árboles durante un período de 2 años. En el laboratorio, las hojas se colocaron en cámara húmeda y se incubaron a temperatura ambiente. Resultados: Se identificaron 100 especies de anamorfos de la división Ascomycota en las hojas de ambos tipos de árboles. No se observaron diferencias en cuanto a la diversidad, equidad y riqueza de especies entre ambos tipos de hojas. Conclusiones: Las especies que componen la comunidad fúngica de las hojas de Scutia buxifolia y Celtis tala es diferente. El tipo de sustrato que representan las hojas de cada especie arbórea condiciona la composición de la comunidad de anamorfos de Ascomycota presentes en ambos tipos de hoja (AU)

Communities of anamorphic fungi on green leaves and leaf litter of native forests of Scutia buxifolia and Celtis tala: Composition, diversity, seasonality and substrate specificity.

BACKGROUND: Xeric forests dominated by two tree species, Scutia buxifolia (Rhamnaceae) and Celtis tala (Ulmacea), are temperate, semi-deciduous wooded communities that represent the most abundant woodlands on the eastern plains of Buenos Aires Province, Argentina. The district of Magdalena has one of the most well-preserved native-forest areas, with an environmental heterogeneity that gives rise to the wide variability in the vegetation present. AIMS: The aim of this study was to analyze the species composition, diversity, seasonal variations, and substrate specificity of anamorphic fungi (Ascomycota) on the green leaves and in the leaf litter of native forests dominated by Scutia buxifolia and Celtis tala from Magdalena, Buenos Aires, Argentina. METHODS: In order to obtain the mycobiota of decomposition, seasonal samples of green leaves and leaf litter from both types of trees were collected over a two-year period. In the laboratory, the leaves were placed in a moist chamber and incubated at room temperature. RESULTS: A total of 100 species of anamorphic Ascomycota were identified in both forests. No significant variations were observed in the richness, diversity, or evenness of the fungal communities of the green leaves and leaf litter of both forests between seasons. CONCLUSIONS: The species that characterized the fungal communities in the leaves of each of the trees were found to be different. The type of substrate had a stronger influence in determining the composition of the fungal community in both types of forests.

Effect of an arbuscular mycorrhizal fungus, Glomus mosseae, and a rock-phosphate-solubilizing fungus, Penicillium thomii, on Mentha piperita growth in a soilless medium.

Rock phosphate effect on English mint (Mentha piperita L.) grown on steamed perlite:vermiculite (1:1, v:v) substrate, with and without rock phosphate, was evaluated in greenhouse experiments. Five treatments were carried out by inoculation with an arbuscular mycorrhizal fungus Glomus mosseae and a phosphorus solubilizing microorganism Penicillium thomii. Plant aerial biomass, phosphorus concentration in plant tissue, and P available in the substrate, were evaluated upon two harvests. After the first harvest, plant aerial biomass did not show significant differences between treatments using rock phosphate as fertilizer, although P content in plants inoculated with P. thomii was higher. The second harvest revealed a higher biomass and plant tissue P content in treatments inoculated with G. mosseae. P. thomii increased P available in the substrate, whereas in the absence of G. mosseae, it did not enhance plant tissue P content. Mycorrhizal colonization was not affected by P. thomii. Microbial inoculation effect on English mint growth was also evaluated. The microbial effect was positive in all treatments when compared with the control without rock phosphate.

Microbióta alcalofílica y alcalinotolerante en suelos de bosques xéricos en una localidad de la provincia de Buenos Aires, Argentina / Alkalophilic and alkali-tolerant mycobiota in xeric forest soils from a locality of the Province of Buenos Aires, Argentina

Se estudió la micobiota alcalofílica y alcalino tolerante de suelos de intercordones del bosque nativo de Celtis tala y Scutia buxifolia en el Partido de Magdalena, provincia de Buenos Aires, Argentina. Los aislamientos de los geohongos se realizaron en agar extractos de malta en rangos de pH desde 5 hasta 11, ajustados mediante diferentes concentraciones de sales sódicas. Se aislaron e identificaron 43 taxa fúngicos. El 50 por ciento no fueron capaces de crecer a pH 10 siendo asignados a la categoría de alcalófilos. El 39 por ciento fueron alcalino-tolerantes dado que pudieron ser aislados hasta pH 10, mientras que el 11 por ciento restante creció a pH 10 pero no a pH 5-6 y fueron asignados a la categoría de alcalofílicos. Sólo Fusarium solari fue aislado con altas frecuencias en suelos de los 3 intercordones en todos lo pH probados.