How do root fungi of Alnus nepalensis and Schima wallichii recover during succession of abandoned land?

Alnus nepalensis and Schima wallichii are native tree species accompanying succession in abandoned agricultural land in the middle mountainous region of central Nepal. To understand how root fungi recover during spontaneous succession, we analyzed the diversity and composition of arbuscular mycorrhizal (AM), ectomycorrhizal (ECM), and total fungi in tree fine roots from three land use types, short-term abandoned land (SA), long-term abandoned land (LA), and regenerated forest (RF) as a reference. Additionally, ECM morphotypes were examined. The results showed different speeds of succession in the studied fungal groups. While the change in the AM fungal community appears to be rapid and LA resembles the composition of RF, the total fungi in the abandoned land types are similar to each other but differed significantly from RF. Interestingly, the relative abundance of Archaeosporaceae followed a trend differing between the tree species (SA < LA in A. nepalensis, but SA > LA in S. wallichii). Unlike AM and total fungi, there was no significant difference in the ECM community of A. nepalensis between land use types, probably due to their low species diversity (9 ECM morphotypes, 31 ECM operational taxonomic units). However, Cortinarius sp. was significantly more abundant in RF than in the other land use types, whereas Alnicola, Tomentella, and Russula preferred young stages. Our results suggest that for both studied tree species the AM fungal succession could reach the stage of regenerated forest relatively fast. In the case of total fungi, because of hyperdiversity and composed of species specialized to a variety of environments and substrates, the transition was expected to be delayed in abandoned land where the vegetation was still developing and the ecosystem was not as complex as that found in mature forests.

Management After Windstorm Affects the Composition of Ectomycorrhizal Symbionts of Regenerating Trees but Not Their Mycorrhizal Networks.

Due to ongoing climate change, forests are expected to face significant disturbances more frequently than in the past. Appropriate management is intended to facilitate forest regeneration. Because European temperate forests mostly consist of trees associated with ectomycorrhizal (ECM) fungi, understanding their role in these disturbances is important to develop strategies to minimize their consequences and effectively restore forests. Our aim was to determine how traditional (EXT) and nonintervention (NEX) management in originally Norway spruce (Picea abies) forests with an admixture of European larch (Larix decidua) affect ECM fungal communities and the potential to interconnect different tree species via ECM networks 15 years after a windstorm. Ten plots in NEX and 10 plots in EXT with the co-occurrences of Norway spruce, European larch, and silver birch (Betula pendula) were selected, and a total of 57 ECM taxa were identified using ITS sequencing from ECM root tips. In both treatments, five ECM species associated with all the studied tree species dominated, with a total abundance of approximately 50% in the examined root samples. Because there were no significant differences between treatments in the number of ECM species associated with different tree species combinations in individual plots, we concluded that the management type did not have a significant effect on networking. However, management significantly affected the compositions of ECM symbionts of Norway spruce and European larch but not those of silver birch. Although this result is explained by the occurrence of seedlings and ECM propagules that were present in the original forest, the consequences are difficult to assess without knowledge of the ecology of different ECM symbionts.

Taxi drivers: the role of animals in transporting mycorrhizal fungi.

Dispersal of mycorrhizal fungi via animals and the importance for the interacting partners' life history as well as for ecosystems is an understudied topic. In this review, we describe the available evidence and the most important knowledge gaps and finally suggest ways to gain the missing information. So far, 33 articles have been published proving a successful transfer of mycorrhizal propagules by animals. The vast majority of research on invertebrates was focused on arbuscular mycorrhizal (AM) fungi, whereas papers on vertebrates (mainly rodents and artiodactyls) equally addressed ectomycorrhizal (ECM) and AM fungi. Effective dispersal has been mostly shown by the successful inoculation of bait plants and less commonly by spore staining or germination tests. Based on the available data and general knowledge on animal lifestyles, collembolans and oribatid mites may be important in transporting ECM fungal propagules by ectozoochory, whereas earthworms, isopods, and millipedes could mainly transfer AM fungal spores in their gut systems. ECM fungal distribution may be affected by mycophagous dipterans and their hymenopteran parasitoids, while slugs, snails, and beetles could transport both mycorrhizal groups. Vertebrates feeding on fruit bodies were shown to disperse mainly ECM fungi, while AM fungi are transported mostly accidentally by herbivores. The important knowledge gaps include insufficient information on dispersal of fungal propagules other than spores, the role of invertebrates in the dispersal of mycorrhizal fungi, the way in which propagules pass through food webs, and the spatial distances reached by different dispersal mechanisms both horizontally and vertically.

Management regime is the most important factor influencing ectomycorrhizal species community in Norway spruce forests after windthrow.

Ectomycorrhizal (ECM) fungi, as symbionts of many tree species in temperate forests, are thought to play an important role in forest regeneration processes after large disturbances. Their reaction to different disturbance and management regimes was studied in spruce forests (Lariceto-Piceetum) 10 years after a severe windthrow in the Tatra National Park (Slovak Republic). ECM community structure was compared between different "management types″-cleared area (EXT), area affected by wildfire (FIRE), uncleared area left for natural development (NEX), and mature forest as a control (REF). Based on Illumina sequencing of soil samples, we determined that the percentage of sequences assigned to ECM fungi decreased with increasing disturbance and management intensity (REF → NEX → EXT → FIRE). Similarly, the total number of ECM species per each of ten sampling points per plot (100 ha) differed between managed (EXT-11 species, FIRE-9) and unmanaged (NEX-16, REF-14) treatments. On the other hand, the percentage of sequences belonging to ericoid mycorrhizal fungi increased. Management type significantly influenced the composition of the ECM community, while vegetation and soil characteristics explained less data variation. The ECM species assemblage of the unmanaged site (NEX) was the most similar to the mature forest, while that of the burnt site was the most different. Thelephora terrestris dominated in all treatments affected by windthrow, accompanied by Tylospora fibrillosa (NEX) and Tylospora asterophora (EXT and FIRE). Management regime was also the most important factor affecting ECM species composition on the roots of spruce seedlings assessed by Sanger sequencing.

Phylogenetic studies in Psathyrella focusing on sections Pennatae and Spadiceae--new evidence for the paraphyly of the genus.

The sections Pennatae and Spadiceae were chosen to test the agreement of current infrageneric classifications of Psathyrella (Psathyrellaceae, Agaricales) with molecular phylogenetic data and to evaluate the systematic significance of relevant morphological characters. The ITS and partial LSU regions of nu-rDNA from 53 specimens representing 34 species of Psathyrella were sequenced and analysed with parsimony-based and model-based phylogenetic methods. According to our analyses, the sections Pennatae and Spadiceae are polyphyletic and distributed across the family Psathyrellaceae, which is divided into at least five major groups. The first one comprises most of the included Psathyrella species and, probably, the whole genus Coprinellus. The second group is made up of Psathyrella gossypina and P. delineata. The third clade consists of the genus Coprinopsis and includes Psathyrella aff. huronensis and P. marcescibilis. The fourth clade is composed of two sister groups, the subgenus Homophron and the genus Lacrymaria, and the fifth group represents the genus Parasola including Psathyrella conopilus. These results are in agreement with neither the current circumscription of the two subgenera, Psathyra and Psathyrella, nor with the pre-sent disposition of the Psathyrellaceae. Taxonomically important morphological characters in the genus Psathyrella show a high degree of homoplasy. Although these characters are useful for species delimitation, and in some cases for the circumscription of sections, they appear insufficient for a phylogenetically correct generic concept.