دانلود رایگان مقاله معرفی دوباره گونه های قارچی در معرض تهدید از طریق تلقیح

Abstract

Reintroduction of locally extinct species is increasingly applied as a conservation tool for re-establishing species within their historical ranges. Thus far, this option has however not been investigated for fungi other than lichens. A large fraction of wood-inhabiting fungal species have declined because of forest loss and fragmentation, in addition to a decrease in dead wood. Here, we show the results from an experiment carried out in southern Finland, which demonstrates that inoculation is an effective method for reintroducing threatened wood-inhabiting fungi. All selected red-listed fungal species successfully established in the inoculated logs as mycelia, and three out of the seven produced fruit-bodies. Success rate was greater when the strains were inoculated in early-decay logs, including species that usually fruit in late decay stages. Inoculation can provide an effective tool for reintroducing fungal species, as the source populations remain intact and it is possible to produce massive amounts of inoculation-units with relatively low cost. Reintroductions of fungi should however be preceded by a risk assessment of the species to be reintroduced, by using source populations from nearby localities, and they should be considered complementary to the primary target of increasing the amount of their habitat. Our results suggest that the reintroductions of threatened fungi via inoculation in combination with other conservation measures can have important bearings for forest conservation and restoration.

4. Discussion

Our results demonstrate that inoculation can be an efficient method for reintroducing red-listed wood-inhabiting fungal species, as all inoculated species established as mycelia and some of them produced reproductive structures in the inoculated logs. We recorded also colonizations outside the inoculated logs, which suggest that inoculations of individual logs can lead to the establishment of local populations. Nevertheless, the latter result is not conclusive, as we observed only a limited number of colonizations, and did not analyze genetically whether the individuals found outside the inoculated logs were derived from the inoculated individuals. In line with previous findings, our results show that the fruiting of threatened wood-inhabiting fungal species mainly occurs after a long delay since mycelial colonization (Ovaskainen et al., 2013), which in our case corresponded to the time since the focal species were inoculated. Thus, it is possible that some of the inoculated wood-inhabiting fungal individuals may still fruit in the future, and in particular that colonizations to logs not inoculated will increase after several years. While the numbers of inoculated individuals that successfully established were relatively low, we note that threatened woodinhabiting fungal species are rare also in their natural ranges (Berglund et al., 2011; Nordén et al., 2013). Even with low numbers of successfully established individuals, the numbers of focal species detected as fruit-bodies in the last survey since inoculation was signifi- cantly higher than expected from the background colonization rate. However, we note that our control-forest approach was not optimal. First, its results were conservative, as we assumed that all observations from the control forests were new colonizations. Second, we did not control for the potential influence of the disturbance generated by drilling the logs. Thus, a more rigorous way for conducting our experiment would have been to have control forests in which the logs would have been inventoried and drilled at the same time as when the species were inoculated, and which would have been then monitored for fungal colonizations at the same time as the inoculated sites. Another alternative for this would have been to genetically analyze whether the emerging fruit-bodies derived from the inoculated individuals. In the case of animals and