Ecotones are interesting portions of forests where microorganisms can be studied for monitoring and diversity purposes. Given the faster life cycle of these organisms, their study in such a context ...is important to develop models that allow us to understand adaptive microbial dynamics. The main objective of this study was to evaluate the dynamics of myxomycetes present in the leaf litter layer in different geographical locations representing both temperate and tropical systems, using an experimental approach within the ecotones produced by sharp forest edges. Employing the moist chamber technique and three ecological indicators (species richness, diversity, and number of records, as a proxy for abundance) associated with the reproductive phase of the life cycle of myxomycetes, the present study summarized the potential effect of both temperate and tropical ecotones on the distribution of these organisms. Data from 26 locations in six countries showed that all indicators were higher in temperate than in tropical forests and that most differences could be explained by ecological effects. The overall influence of the ecotone on myxomycetes was opposite in temperate and tropical forests, but the data collected for both types of forests showed similarities that could be explained by comparable mathematical models. These results suggested that, with the methods used herein, ecotones do affect ecological patterns of myxomycetes, but the intensity and directionality of such an effect differ depending on the forest type involved.
The assemblages of myxomycetes associated with the three types of temperate grasslands (tall grass, mixed grass and short grass) found across the western central United States were examined by ...collecting samples for isolation of these organisms from nine study sites. Samples consisted of two types of ground litter, two types of aerial litter (dead but still attached plant parts) and dung. These were brought back to the laboratory and used to prepare a series of moist chamber cultures. These cultures yielded 1,301 collections of myxomycetes representing 59 species in 18 genera. Some collections could be identified only to genus and one in particular (
Lepidoderma
sp.) appears to be an undescribed taxon.
Physarum spectabile
was recorded for the first time in North America. Overall, only eight species (
Badhamia melanospora
,
Didymium anellus
,
D
.
difforme
,
D
.
squamulosum
,
Perichaena depressa
,
Physarum cinereum
,
P
.
pusillum
, and
Stemonitis fusca
) were recovered from all nine study sites and thus are considered to represent a core component of the myxomycete biota of temperate grasslands.
The ectomycorrhizal fungi associated with American chestnut (Castanea dentata) were characterized using DNA extracted from the root-tips of naturally occurring saplings from a forest in northeastern ...Tennessee. A total of 18 taxa were recorded, although one of these (Oidiodendron maius) was surprising because it has been reported previously to form what appear to be mycorrhizal associations only with members of the Ericaceae. One-third of the recorded taxa were representatives of the genera Russula or Lactarius (both members of the family Russulaceae), and three other genera (Cortinarius, Tomentella, and Tricholoma, each represented by two species). The data presented herein at least suggest that members of the Russulaceae are among the most common and widespread ectomycorrhizal fungi associated with naturally occurring individuals of American chestnut in the forests of eastern North America in which it was once dominant. However, it should be pointed out that our data are limited and thus are best considered as preliminary.
Ten small dictyostelids isolated from samples collected from the surface humus layer of seasonal rainforests of Belize and Guatemala were studied morphologically, and nine were found to represent ...distinct species, all with an average height of < 2 mm (0.5-3.5 mm). Although their fruiting bodies (sorocarps) closely resemble one another, the nine species differ in their patterns of aggregation, stream pattern, branching development, formation of microcysts, spore shape, presence or absence of spore granules and their distribution, as well as in the shapes and behavior of their sorogens and myxamoebae. These stable morphological features were sufficient to recognize nine new species of small dictyostelids, one with two varieties. SSU rDNA sequences were generated for all these new isolates, and phylogenetic analyses of these sequences show these new isolates belong to Dictyostelid group 3. As a result of this and other recent studies, the concept of what constitutes a species in the dictyostelids has become much more restricted and well defined, in as much as some of the morphological and behavioral patterns now being observed were overlooked in the past. The extent, flow direction and conformation of streaming within the group varies from simple aggregation mounds with no streams to short streams, to somewhat longer streams and finally to well developed streams. Each of these is characterized by a particular set of distinguishing features.
Dictyostelid cellular slime molds (dictyostelids) associated with grassland ecosystems of the central and western United States were investigated at nine sites that included examples of the three ...major ecological types of grasslands (tall grass, mixed grass and short grass) generally recognized for the region. Samples of soil/humus collected from each site were examined with the Cavender method of isolating dictyostelids. For each of those six sites with well developed gallery forests present, an additional set of forest soil/humus samples was collected. A more intensive sampling effort was carried out at one site (Konza LTER) to assess the possible effects of burning and grazing on dictyostelid diversity and density. Twelve species of dictyostelids were recovered from grassland sites, whereas gallery forest sites yielded only nine species. Four cosmopolitan species (Dictyostelium giganteum, D. mucoroides, D. sphaerocephalum and Polysphondylium pallidum) were represented by the greatest densities of clones, with D. sphaerocephalum particularly common. The general pattern across all sites was that both species richness and density of dictyostelids decreased with decreasing precipitation. Samples collected from ungrazed grassland plots yielded higher numbers of both species and clones as compared to grazed plots, and the general pattern was for both values to increase as the interval between fires increased. For numbers of clones this correlation was statistically significant.
Taxonomic names are key links between various databases that store information on different organisms. Several global fungal nomenclural and taxonomic databases (notably Index Fungorum, Species ...Fungorum and MycoBank) can be sourced to find taxonomic details about fungi, while DNA sequence data can be sourced from NCBI, EBI and UNITE databases. Although the sequence data may be linked to a name, the quality of the metadata is variable and generally there is no corresponding link to images, descriptions or herbarium material. There is generally no way to establish the accuracy of the names in these genomic databases, other than whether the submission is from a reputable source. To tackle this problem, a new database (FacesofFungi), accessible at www.facesoffungi.org (FoF) has been established. This fungal database allows deposition of taxonomic data, phenotypic details and other useful data, which will enhance our current taxonomic understanding and ultimately enable mycologists to gain better and updated insights into the current fungal classification system. In addition, the database will also allow access to comprehensive metadata including descriptions of voucher and type specimens. This database is user-friendly, providing links and easy access between taxonomic ranks, with the classification system based primarily on molecular data (from the literature and via updated web-based phylogenetic trees), and to a lesser extent on morphological data when molecular data are unavailable. In FoF species are not only linked to the closest phylogenetic representatives, but also relevant data is provided, wherever available, on various applied aspects, such as ecological, industrial, quarantine and chemical uses. The data include the three main fungal groups (Ascomycota, Basidiomycota, Basal fungi) and fungus-like organisms. The FoF webpage is an output funded by the Mushroom Research Foundation which is an NGO with seven directors with mycological expertise. The webpage has 76 curators, and with the help of these specialists, FoF will provide an updated natural classification of the fungi, with illustrated accounts of species linked to molecular data. The present paper introduces the FoF database to the scientific community and briefly reviews some of the problems associated with classification and identification of the main fungal groups. The structure and use of the database is then explained. We would like to invite all mycologists to contribute to these web pages.
During the period of 1992 to 1994, ten belt transects, each consisting of a series of contiguous 10 × 10 m (100 m2) quadrats, were established and sampled at seven study sites in southwestern ...Virginia and eastern central West Virginia. Each transect extended from a red spruce-dominated community through the ecotone and into the adjacent hardwood community. In 2004 and 2005, these same transects were resampled in order to assess changes that had occurred. As a general trend, red spruce either maintained its ecological status or increased in number in all size classes, with noticeable expansion into the hardwood community at some study sites.
Results obtained in studies of grassland myxomycetes (plasmodial slime molds or myxogastrids), based on the species appearing in moist-chamber cultures, have indicated that forb microhabitats yield ...considerably more collections than grass microhabitats. We experimentally evaluated this pattern at the Tall Grass Prairie Preserve in Oklahoma by using litterbags prepared with autoclaved samples of grasses and forbs. We obtained a total of 162 collections representing 20 species; Perichaena pedata and Diderma effusum were the dominant species present. Total number of collections, species richness, and species diversity were significantly higher for forb microhabitats when compared to grass microhabitats. These results corroborate previous reports and demonstrate the utility of using litterbags as an experimental approach to assess myxomycete diversity and to confirm or refute observations from previous ecological studies.
Data were obtained on the assemblages of corticolous myxomycetes (plasmodial slime moulds or myxogastrids) associated with the bark surface of living white oak (Quercus alba) trees from two different ...size classes. Bark samples obtained from larger trees were characterized by higher values for both species richness and diversity when compared to those collected from smaller trees. This might have been expected since the former possess a larger surface area and presumably have persisted over a longer period of time. However, the myxomycete assemblage associated with smaller trees was appreciably different and did not simply represent a depauperate version of the assemblage associated with larger trees. This suggests that the differences observed between size classes cannot be simply attributed to size alone.
•We surveyed the myxomycete assemblages of small and large white oak trees.•Large trees were characterized by a greater richness and diversity of myxomycetes.•Myxomycete composition and structure differed between the two size classes.•Tree size alone is insufficient to explain the observed differences.
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