Fungal sporocarps house diverse and host-specific communities of fungicolous fungi

Sporocarps (fruit bodies) are the sexual reproductive stage in the life cycle of many fungi. They are highly nutritious and consequently vulnerable to grazing by birds and small mammals, and invertebrates, and can be infected by microbial and fungal parasites and pathogens. The complexity of communities thriving inside sporocarps is largely unknown. In this study, we revealed the diversity, taxonomic composition and host preference of fungicolous fungi (i.e., fungi that feed on other fungi) in sporocarps. We carried out DNA metabarcoding of the ITS2 region from 176 sporocarps of 11 wood-decay fungal host species, all collected within a forest in northeast Finland. We assessed the influence of sporocarp traits, such as lifespan, morphology and size, on the fungicolous fungal community. The level of colonisation by fungicolous fungi, measured as the proportion of non-host ITS2 reads, varied between 2.8-39.8% across the 11 host species and was largely dominated by Ascomycota. Host species was the major determinant of the community composition and diversity of fungicolous fungi, suggesting that host adaptation is important for many fungicolous fungi. Furthermore, the alpha diversity was consistently higher in short-lived and resupinate sporocarps compared to long-lived and pileate ones, perhaps due to a more hostile environment for fungal growth in the latter too. The fungicolous fungi represented numerous lineages in the fungal tree of life, among which a significant portion was poorly represented with reference sequences in databases.Peer reviewe

Impacts of Forest Management on Forest Bird Occurrence Patterns-A Case Study in Central Europe

The global increase in demand for wood products, calls for a more sustainable management of forests to optimize both the production of wood and the conservation of forest biodiversity. In this paper, we evaluate the status and future trends of forest birds in Central European forests, assuming different forest management scenarios that to a varying degree respond to the demand for wood production. To this end, we use niche models (Boosted Regression Trees and Generalized Linear Models) to model the responses of 15 forest bird species to predictors related to forest stand (e.g., stand volume of specific tree species) and landscape structure (e.g., percentage cover), and to climate (bioclimatic variables). We then define five distinct forest management scenarios, ranging from set-aside to productivity-driven scenarios, project them 100 years into the future, and apply our niche models into these scenarios to assess the birds' responses to different forest management alternatives. Our models show that the species' responses to management vary reflecting differences in their ecological niches, and consequently, no single management practice can benefit all species if applied across the whole landscape. Thus, we conclude that in order to promote the overall forest bird species richness in the study region, it is necessary to manage the forests in a multi-functional way, e.g., by spatially optimizing the management practices in the landscape

European mushroom assemblages are darker in cold climates

Abstract: Thermal melanism theory states that dark-colored ectotherm organisms are at an advantage at low temperature due to increased warming. This theory is generally supported for ectotherm animals, however, the function of colors in the fungal kingdom is largely unknown. Here, we test whether the color lightness of mushroom assemblages is related to climate using a dataset of 3.2 million observations of 3,054 species across Europe. Consistent with the thermal melanism theory, mushroom assemblages are significantly darker in areas with cold climates. We further show differences in color phenotype between fungal lifestyles and a lifestyle differentiated response to seasonality. These results indicate a more complex ecological role of mushroom colors and suggest functions beyond thermal adaption. Because fungi play a crucial role in terrestrial carbon and nutrient cycles, understanding the links between the thermal environment, functional coloration and species’ geographical distributions will be critical in predicting ecosystem responses to global warming

European mushroom assemblages are darker in cold climates

Abstract: Thermal melanism theory states that dark-colored ectotherm organisms are at an advantage at low temperature due to increased warming. This theory is generally supported for ectotherm animals, however, the function of colors in the fungal kingdom is largely unknown. Here, we test whether the color lightness of mushroom assemblages is related to climate using a dataset of 3.2 million observations of 3,054 species across Europe. Consistent with the thermal melanism theory, mushroom assemblages are significantly darker in areas with cold climates. We further show differences in color phenotype between fungal lifestyles and a lifestyle differentiated response to seasonality. These results indicate a more complex ecological role of mushroom colors and suggest functions beyond thermal adaption. Because fungi play a crucial role in terrestrial carbon and nutrient cycles, understanding the links between the thermal environment, functional coloration and species’ geographical distributions will be critical in predicting ecosystem responses to global warming

Long‐term effects of colonization‐extinction dynamics of generalist versus specialist wood‐decaying fungi

Long‐term metapopulation persistence is mediated by the dynamics of colonization and extinction. To understand and predict future species occupancy in changing landscapes, we must account for the dynamic rates that shape the occupancy and disentangle their dependence on environmental conditions. Specialist and generalist species may differ in their dynamics in systematic ways. Using an extensive, large‐scale repeat survey dataset for wood‐decaying fungi, we fitted dynamic metapopulation models for ten species, ranging from generalists to specialists with differing resource requirements. We first estimated base rates of colonization and extinction and tested their relationships to species' degree of specialization. We then tested for effects of local and landscape scale variables on the colonization and extinction rates. Finally, using the fitted models and a scenario of future forest development we projected future colonization–extinction dynamics over 100 years to test for differences in species occupancies between production stands and set‐aside stands. Our study revealed a striking pattern of decreasing colonization rates with increasing degree of specialization across species, along with concomitantly increasing extinction rates. Strong sensitivity of colonization probabilities to local habitat quality (dead wood volume and stand age) in specialist but not generalist species constrained the regional occupancy of specialists, especially in production forest. We found evidence for short‐range dispersal limitation in two specialists, but no effect of our measure for landscape‐scale connectivity on colonization rates. Simulations of future metapopulation dynamics resulted in decreasing and lower final occupancy in production forest than in set‐asides, especially of specialist species. In set‐aside stands, however, specialists increased over time to relatively high occupancies. Synthesis. Colonization–extinction dynamics of wood‐decaying fungi varied with species' degree of specialization. Increasing specialization was associated with increasing sensitivity of colonization rates to habitat conditions, and partly local connectivity, as well as with increasing extinction rates. Low landscape‐scale occupancies of specialist as compared to generalist wood‐decaying fungi are thus maintained by a combination of lower colonization rates, particularly in production forest, and higher extinction rates

Fungal sporocarps house diverse and host-specific communities of fungicolous fungi

Sporocarps (fruit bodies) are the sexual reproductive stage in the life cycle of many fungi. They are highly nutritious and consequently vulnerable to grazing by birds and small mammals, and invertebrates, and can be infected by microbial and fungal parasites and pathogens. The complexity of communities thriving inside sporocarps is largely unknown. In this study, we revealed the diversity, taxonomic composition and host-preference of fungicolous fungi (i.e fungi that feed on other fungi) in sporocarps. We carried out DNA metabarcoding of the ITS2 region from 176 sporocarps of 11 wood-decay fungal host species, all collected within a forest in northeast Finland. We assessed the influence of sporocarp traits, such as lifespan, morphology and size, on the fungicolous fungal community. The level of colonisation by fungicolous fungi, measured as the proportion of non-host ITS2 reads, varied between 2.8-39.8% across the 11 host species and was largely dominated by Ascomycota. Host species was the major determinant of the community composition and diversity of fungicolous fungi, suggesting that host adaptation is important for many fungicolous fungi. Furthermore, the alpha-diversity was consistently higher in short-lived and resupinate sporocarps compared to long-lived and pileate ones, perhaps due to a more hostile environment for fungal growth in the latter too. The fungicolous fungi represented numerous lineages in the fungal tree of life, among which a significant portion was poorly represented with reference sequences in databases.A README file is provided and accessile upon down of the data. Data submission accompanying the article "Fungal sporocarps house diverse and host-specific communities of fungicolous fungi." The data is structured into 2 sections: 1- The rawdata availble in the directory ""Issakka-ITS_rawdata". 2- FungicolousFungi that contains 2 dsub-directories + README file The bioinformatics filtering of the OTU table, the mapping files for demultiflexing the rawdata, the scripts and input and output files. Funding provided by: Norges ForskningsrådCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100005416Award Number: 254746Funding provided by: FP7 People: Marie-Curie ActionsCrossref Funder Registry ID: http://dx.doi.org/10.13039/100011264Award Number: 628326Funding provided by: NansenFondet*Crossref Funder Registry ID: Award Number: Funding provided by: NansenFondetCrossref Funder Registry ID:The raw data "rawdata_metabarcodingITS2", which has been generated from the metabarcoding of the ITS2 region amplified with gITS7 and ITS4 primers for 192 samples processed with 2 *96 unique barcodes, PE sequenced in one MiSeq Illumina lane (StarSeq, Germany) to generate 2 x 300 bp reads. The raw sequencing data is available in the folder "Issakka-ITS_rawdata"

Occupancy versus colonization-extinction models for projecting population trends at different spatial scales

Understanding spatiotemporal population trends and their drivers is a key aim in population ecology. We further need to be able to predict how the dynamics and sizes of populations are affected in the long term by changing landscapes and climate. However, predictions of future population trends are sensitive to a range of modeling assumptions. Deadwood-dependent fungi are an excellent system for testing the performance of different predictive models of sessile species as these species have different rarity and spatial population dynamics, the populations are structured at different spatial scales, and they utilize distinct substrates. We tested how the projected large-scale occupancies of species with differing landscape-scale occupancies are affected over the coming century by different modeling assumptions. We compared projections based on occupancy models against colonization-extinction models, conducting the modeling at alternative spatial scales and using fine- or coarse-resolution deadwood data. We also tested effects of key explanatory variables on species occurrence and colonization-extinction dynamics. The hierarchical Bayesian models applied were fitted to an extensive repeated survey of deadwood and fungi at 174 patches. We projected higher occurrence probabilities and more positive trends using the occupancy models compared to the colonization-extinction models, with greater difference for the species with lower occupancy, colonization rate, and colonization:extinction ratio than for the species with higher estimates of these statistics. The magnitude of future increase in occupancy depended strongly on the spatial modeling scale and resource resolution. We encourage using colonization-extinction models over occupancy models, modeling the process at the finest resource-unit resolution that is utilizable by the species, and conducting projections for the same spatial scale and resource resolution at which the model fitting is conducted. Further, the models applied should include key variables driving the metapopulation dynamics, such as the availability of suitable resource units, habitat quality, and spatial connectivity

At which spatial and temporal scales can fungi indicate habitat connectivity?

Isolation of habitats in space and time affects species globally and in a multitude of ecosystems [1]. It is however often difficult to assess the level of isolation from the point of view of the focal species [2]. Wood-decaying fungal species have been used as indicators of 'conservation value' in Europe [3] and North America. The indicator species were commonly assigned based on expert opinions, but few scientific evaluations have been performed of what these species actually indicate. Building on previous classifications of wood-decaying fungal indicator species on Norway spruce, we hypothesized that indicator species would differ from non-indicator species in how they respond to local temporal connectivity - forest age, the intensity of historical selective logging and the presence of well-decomposed large logs, and to local and landscape-scale spatial connectivity - local forest area, local amount of deadwood and the connectivity to old forest in the surrounding landscape. Based on fungal occurrence data from a fixed number of spruce logs at 28 sites distributed across Scandinavia, we explored the spatiotemporal scales at which the local communities were affected by connectivity. Indicator species showed the strongest response to connectivity of old forest (≥80 years) within 100 km, while non-indicator species depended on connectivity of younger forest (≥40 years) at a smaller spatial scale (≤25 km). Indicator species increased and non-indicator species decreased in total abundance with the increasing age of the local forest stand. Landscape-scale old-forest connectivity was beneficial for indicator species in all sites except those with relatively low amount of deadwood, while non-indicator species showed the opposite pattern. We identify a threshold of around 47 m3 ha-1 in the amount of deadwood where indicator species become abundant enough to influence non-indicator species through competitive interactions. There was a pronounced uniformity within each species group in the connectivity responses. We conclude that the studied indicator species indicate high forest age, high amount of resources and, given that the resources are plentiful, also high old-forest connectivity, but they do not indicate a long history without any logging operations or local deadwood continuity. The studied non-indicator species did not indicate any of the studied spatiotemporal connectivity variables. Indicator species are usually red-listed and may continue to decline in the future without habitat restoration efforts Key references: 1 Wilson et al. (2016). Habitat fragmentation and biodiversity conservation: key findings and future challenges. Landscape Ecology, 31, 219-227. 2 Haddad et al. (2015). Habitat fragmentation and its lasting impact on Earth's ecosystems. Science Advances, 1, e1500052. 3 Nitare & Hallingbäck (2010). Signalarter: indikatorer på skyddsvärd skog: flora över kryptogamer. Skogsstyrelsens förlag, Jönköping.peerReviewe

Impacts of Forest Management on Forest Bird Occurrence Patterns

The global increase in demand for wood products, calls for a more sustainable management of forests to optimize both the production of wood and the conservation of forest biodiversity. In this paper, we evaluate the status and future trends of forest birds in Central European forests, assuming different forest management scenarios that to a varying degree respond to the demand for wood production. To this end, we use niche models (Boosted Regression Trees and Generalized Linear Models) to model the responses of 15 forest bird species to predictors related to forest stand (e.g., stand volume of specific tree species) and landscape structure (e.g., percentage cover), and to climate (bioclimatic variables). We then define five distinct forest management scenarios, ranging from set-aside to productivity-driven scenarios, project them 100 years into the future, and apply our niche models into these scenarios to assess the birds’ responses to different forest management alternatives. Our models show that the species’ responses to management vary reflecting differences in their ecological niches, and consequently, no single management practice can benefit all species if applied across the whole landscape. Thus, we conclude that in order to promote the overall forest bird species richness in the study region, it is necessary to manage the forests in a multi-functional way, e.g., by spatially optimizing the management practices in the landscape

Impacts of Forest Management on Forest Bird Occurrence Patterns

The global increase in demand for wood products, calls for a more sustainable management of forests to optimize both the production of wood and the conservation of forest biodiversity. In this paper, we evaluate the status and future trends of forest birds in Central European forests, assuming different forest management scenarios that to a varying degree respond to the demand for wood production. To this end, we use niche models (Boosted Regression Trees and Generalized Linear Models) to model the responses of 15 forest bird species to predictors related to forest stand (e.g., stand volume of specific tree species) and landscape structure (e.g., percentage cover), and to climate (bioclimatic variables). We then define five distinct forest management scenarios, ranging from set-aside to productivity-driven scenarios, project them 100 years into the future, and apply our niche models into these scenarios to assess the birds’ responses to different forest management alternatives. Our models show that the species’ responses to management vary reflecting differences in their ecological niches, and consequently, no single management practice can benefit all species if applied across the whole landscape. Thus, we conclude that in order to promote the overall forest bird species richness in the study region, it is necessary to manage the forests in a multi-functional way, e.g., by spatially optimizing the management practices in the landscape