Angelo Rambelli

Comparative studies on microfungi in tropical ecosystems in Ivory Coast forest litter: behaviour on different substrata

Fungal colonies sporulating on 71 kinds of leaves that fell during the dry season in the Tai National Park (Ivory Coast) were analysed. A consistent connection between certain fungal species and their substrata was detected among the 184 fungal species that were identified. Each fungal species was characterized according to morphological and ecological features. Multidimensional scaling showed that certain ubiquitous and common species have morphological characters distinguishing them from specialised species.

Succession of microfungal communities on Myrtus communis leaf litter in a Sardinian Mediterranean maquis ecosystem

The succession of microfungal communities on Myrtus communis leaf litter was monitored from Jan. 1993 to Nov. 1994 using the litter bag method. Three main groups of fungal colonizers were identified, whose presence is correlated with the successive decomposition stages of the substrate and with seasonal variations.

Analysis of the litter microfungal communities in a mediterranean maquis ecosystem

Combative-ruderal and stress-tolerant microfungal communities on mediterranean vegetation litter in three different stations in Sardinia were analysed. The saprotrophic specialization of some fungal species onPistacia lentiscus L. substratum is discussed.RiassuntoÈ stata analizzata l’evoluzione di una comunità fungina da una tipica situazione «combative-ruderal» ad una di «stress». Le ricerche sono state effettuate in tre stazioni costiere a macchia mediterranea in Sarde-gna; le comunità fungine associate alla lettiera délle differend specie vegetali sono state esaminate in due differenti periodi stagionali, primavera ed estate. Sono state identificate tre Strategie di sopravvivenza: 1a prima dei «combative-ruderal», la seconda degli «stress-tolerant» e 1a terza è adottata da quelle specie fungine che beneficiano delle condizioni stressanti dell’ambiente. Poiché le colonie fungine identificate sulle differenti lettiere presentano contorni ben delimitati, sono stati identificati e proposti due differenti tipi di colonizzazione, ottimale ed adattativo. In particolare è stata discussa 1a specializzazione saprotrofica di al-cune specie fungine sulla lettiera diP. lentiscus.

A study on micro-fungi in arid areas. Notes on stress-tolerant fungi

ABSTRACT Severe selectivity by extreme environments was investigated in mitosporic fungi with regard to their adaptive responses to high temperature, and to high levels of sunlight and evapo-transpiration. A homogeneous group of graminicolous dematiaceous hyphomycetes was removed from sand dunes in the torrid climate of the Namib Naukluft Park, from arid, clayey soil at Etosha pan and from calcareous crusts in the Namib Desert Park: all of them produce darkening conidiophores and deeply pigmented spores. The size and colour of reproductive structures were recorded and compared with bibliographic data. Results are consistent with a uniform morpho-functional response by these fungi to stress conditions.

Primo contributo alla micoecologia della lettiera di lentisco in alcune isole minori della Sardegna meridionale

Abstract Preliminary account of the microfungi colonizing Pistaca lentiscus L. litter - A preliminary account of the microfungi colonizing Pistacia lentiscus L. leaf litter in five small islands of South Sardinia is carried out. Two species, Beltrania rhombica Penzig and Endophragmiella boewei (Crane) Hughes are present in almost all the samples investigated. A very low index in richness of species seems to be characteristic of this particular area.

Pestalotiopsis Endophytes from Leaves of Two Orchid Species Collected in Costa Rica

Abstract A survey of endophytic Pestalotiopsis associated with two orchid species collected in Coco Island in Costa Rica was carried out. Among the fungi isolated from leaves of the two species, genus Pestalotiopsis prevailed. We isolated 29 strains of Pestalotiopsis, 9 of which from Camaridium micranthum M. A. Blanco and 20 from Ornithidium adendrobium (Rchb.f.) M.A. Blanco. On the basis of morphological characters, Pestalotiopsis isolates were divided into three different groups but their high similarity do not allow unambiguous species identification. The analysis of internal transcribed spacer (ITS) region of ribosomal DNA was then performed to evaluate the taxonomic position of our isolates.

« Chaetopsina ivoriensis » a new species of Dematiaceous Hyphomycetes

Abstract The discover and morphological characters of a Dematiaceous Hyphomycetes are described. The material, studied under a morphological point of view directly collected on the natural substratum, allows us to establish the appartenance to the genus Chaetopsina. Since this species does not appeare described till now, the Authors propose for it the nomenclature ivoriensis as a new species.

Succession of microfungi during Pistacia lentiscus litter decomposition in a Sardinian Mediterranean maquis

Abstract Changes in the microfungal community developing on Pistacia lentiscus L. leaf litter were monitored from February 2001 (senescent leaves) to December 2002 using litter bags. The Principal component analysis of the 16 samples showed a microfungal succession related to the progressive decomposition of the substratum. The Correspondence analysis of fungal colonizers with Rf > 10 revealed three main groups succeeding during the study period. The co-occurrence relationships (on the same leaf) among the major colonizers were analysed. The specialized saprotrophs on P. lentiscus litter: Asterostomella sp. 1 and Endophragmiella boewei were identified as principal colonizers in the mature community.

Contribution to the study of the microfungi in the saprotrophic specialization in tropical forest litter

Abstract In this study we have reported some results of the fungal colonization in the litter of different plants of the National Park of Tai (Ivory Coast). We have also examined the correlations between the fungal species and the vegetable matrix in order to detect a saprotrophic specialization.

A study on micro-fungi in arid areas: Notes on soil saprotrophs and animal opportunistic pathogens

ABSTRACT Soil fungi were studied in three desert areas in Namibia with the aim of identifying saprotrophic microorganisms associated with animal communities as opportunistic pathogens. The extremely arid environment of the Naukluft Desert Park was found to be more selective for soil fungi, whereas the soils of Etosha Pan, with seasonal wet areas, and the mobile dunes of Sossousvlei, which absorb atmospheric moisture at night by virtue of their proximity to the sea, host saprotrophic microorganisms and potential and/or opportunistic pathogens.