Fungal conservation genetics: Effects of forest fragmentation on genetic diversity in dead wood dependent fungi in space and time

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2016

End date

12/31/2020

Budget

1,098,759 EUR

Fundings

Abstract

During the last centuries, the boreal forests of Fennoscandia have been transformed due to various anthropogenic activities, including forestry. Natural forests have declined and become fragmented. These transformations have led to a reduction in species and populations restricted to natural-like forests. While the loss of species is well studied, much less is known about how forest loss and fragmentation have affected genetic variation within species. Within-species genetic diversity represents a basic diversity component that a sustainable nature management should protect, including genetic diversity. For this purpose, it is important to be aware of whether populations are losing genetic variation, at which rate and what are the factors underlying this decline. In the FunGen project, we are focusing on wood decay fungi of boreal forests, i.e., a group of organisms providing important ecosystem services such as nutrient cycling. Several studies have drawn attention to the decline of the diversity of wood-inhabiting fungi. For these species, reduced genetic variation may mean reduced chances of survival because of decreased fruiting rate, spore production, spore viability and stress tolerance, establishment rate, growth rate and competitive ability. Reduced genetic variation may also mean poor ability to adapt with the changing climate. In the project FunGen, we investigated how forest fragmentation has influenced population dynamics and subsequently genetic variation within wood decay fungi at different spatial scales. We have sampled ca. 300 fruiting bodies for each targeted species (4) from several populations (ca. 20) in Europe (Norway, Sweden, Finland, Poland, Estonia, and Russia). We can conclude that there are different patterns of genetic diversity, some species like Phellopilus nigrolimitatus have relatively large population sizes with weak genetic structure, while other species such as Amylocystis lapponica tend to have smaller population size with more divergence between populations, with small and isolated populations more likely to be affected by forest history (WP1 and WP2). We reintroduce three rare and threatened fungi in three southern boreal landscapes: Nordmarka, Østmarka and Telemark, totaling nine forests (WP4). This translocation experiment has been yearly monitored and will extend above the duration of FunGen. Together with Fylkesmannen I Oslo and Bymiljøetaten, we are also testing the success of species restoration for other fungi and provided guidelines and recommendations for nature management authorities. Using DNA metabarcoding, we assessed bacterial and fungal diversities present in 45 logs, prior to the translocation experiment. We observed a stronger biogeographic structuring of the fungal communities within landscape compared to the bacterial communities that were clearly more affected by forest management practices (WP4). Finally, taking advantage of the big sampling size, we dig into an understudied field of fungal ecology by revealing the fungal diversity living inside fungal fruit bodies. Our results show that fungicolous fungi can make up a large proportion of the sporocarps and that a wide, hitherto largely overlooked, diversity of partly host-specific fungicolous fungi exists (WP3). For WP1 we have finalized the sampling and will focus on three categories of the IUCN classification: least concern, near threatened and vulnerable. Our conclusions are likely to hold the focal rare and threatened species studied, as found similar trends in other wood dependent species.