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• Four tree-scale conservation outcomes of green-tree retention are distinguished. • 38% of retained trees had poor survival combined with low habitat value. • Large aspens had poor survival but supplied valuable dead wood substrate. • Well surviving European nemoral hardwood trees were worth retaining even when small. • Trees likely to develop microhabitats should be facilitated also at thinnings. Retention forestry is a silvicultural approach that can achieve both ecological and economic objectives in various forest ecosystems. It builds largely on the assumption that the live trees left unharvested (the main timber cost) effectively support ecological functioning of post-harvest forest. Such effectiveness can be understood as a combination of the initial ecological value of the tree (that may persist after tree death) and its survival, i.e., the prospect to develop into a high-quality veteran tree in the next forest generation. We assessed those aspects among >3000 live trees actually retained in 103 Estonian harvested sites and monitored over 16 years. We analysed how their survival and habitat value (estimated from tree morphology, confirmed by epiphyte surveys) translate to the veteran-tree perspectives. Only 48% of the trees were still alive after 16 years, and this final survival at the stand-scale was poorly predictable from a few years of monitoring. Only 12% retention trees had both high habitat value and high survival. Most trees (75%) were of low initial habitat value and, combined with low survival, almost 40% of all trees never provided quality habitat for tree-dwelling species. Nevertheless, we found considerable potential for post-harvest development of habitat value; notably in European nemoral hardwood species (such as Fraxinus, Quercus, Ulmus, Acer), which survived well but were usually in subcanopies at the time of the harvest. These findings indicate that retention forestry can improve also highly impoverished (e.g. short-rotation) forests, if analytical tools have been developed and applied to predict tree survival and future habitat quality. [ABSTRACT FROM AUTHOR]

A major question in fungal conservation is why many species are confined to old forests, and how they could be supported by contemporary landscape matrix. Specifically, forestry that retains large biological legacies across landscape could reduce old-forest dependencies to species that require unusual substrate conditions. We sampled polypores in 112 2 ha plots (both old and harvested stands) in a semi-natural forestry context in Estonia and modelled the habitat factors of species confined to old growth. The results confirmed that old-growth assemblages emerged mostly due to diverse and abundant substrate supply (notably downed CWD). Only 10 species (five spruce-dwellers) were confined to old growth; of these, only Fomitopsis rosea and Oxyporus corticola were additionally affected by forest connectivity. The forestry system studied appeared particularly favourable for the species inhabiting deciduous wood. To better address habitat degradation in conservation, expert lists of ‘old-forest (indicator) fungi’ should be replaced with evidence-based focal taxa. [ABSTRACT FROM AUTHOR]

In ecological and biodiversity research, fungal species are traditionally recorded using fruit body sampling, which underestimates mycelial presence of species. We hypothesized that fruit body based species lists are increasingly complete in larger sampling units where fruit bodies can be detected across multiple mycelial occurrences. We compared molecular records (detected with Illumina high-throughput sequencing) and records of fruit bodies of polypores in Estonian wetland pine forests. Of all molecularly detected polypores, 75% were present as conspecific fruit bodies within 30 m (including 24% on the same tree). This distance varied little among study sites. Despite lower costs, fruit body surveys yielded 60 polypore species, while sequencing only detected 13 species. Fruit body surveys of selected macrofungi can be thus efficient for biodiversity assessments. However, combining such surveys with high-throughput sequencing can add a broad description of the whole fungal assemblage even with limited samples (616 OTUs from 30 downed trunks in our study). [ABSTRACT FROM AUTHOR]

Three new species of Hymenochaete from Russian Far East are described based on morphological and ITS rDNA data. Hymenochaete adhaerens sp. nov. is a resupinate species closely related to H. macrospora, from which it differs in having longer basidiospores and setae. The basidiocarps of H. cupulata sp. nov. are effused-reflexed, resembling those of the European H. ulmicola, from which it differs in having setae inflated at the basal part and shorter basidiospores. Both H. adhaerens and H. cupulata inhabit bark of living elm trees ( Ulmus spp.). H. manshurica sp. nov. is resupinate and morphologically similar to the North American H. corticolor, from which it differs in having narrower setae and basidiospores; it has been collected from bark of living Tilia manshurica. [ABSTRACT FROM AUTHOR]

Abstract: Putatively old-forest dependent fungi have acquired a distinct position in biodiversity conservation, acting both as management targets and indicators for other nature values in the forest. Establishing old-forest dependency, however, requires rigorous sampling, taxonomy and identification approaches as exemplified here by a case study on Antrodia crassa. This rarely recorded polypore is considered indicative of old conifer forests in Northern Europe. We demonstrate that the material labelled as A. crassa includes not only frequent misidentifications, but it represents two genetically and ecologically distinct cryptic lineages with partly overlapping distributions. A balanced survey of different successional stages in Estonia indicated that one of those lineages prefers deadwood-rich disturbed habitats, notably clear-cuts, which have been previously undersampled. Because similar problems with cryptic lineages and biased surveys are common in mycological research, lists of ‘old-forest fungi’ should be considered as high-priority working hypotheses for taxonomic and ecological research, rather than well-established management tools. [Copyright &y& Elsevier]

• We measure the habitat relationships of wood-inhabiting fungi using DNA metabarcoding. • Old stands had larger species pools, at the landscape but not at the trunk scale. • High landscape-scale forest cover supported trunk scale fungal richness. • Increase in local dead-wood volume increased number of red-listed species per trunk. • Conservation conclusions based on DNA in wood same as in former fruit-body surveys. Understanding the distribution of biodiversity across forest landscapes is a key issue for the spatial planning of conservation management. Obtaining such spatial perspective is challenging because a large part of biodiversity remains hidden to the conventional survey approaches. High-productivity forests are probably the hotspots of hidden biodiversity and, at the same time, under severe timber harvesting pressure. We used DNA-metabarcoding approach to assess habitat quality of successional high productivity forests for wood-inhabiting fungi, focusing on fungal diversity that remains hidden in fruit-body surveys. We sampled a fixed amount of coarse fallen Norway spruce trunks in 40 naturally developing stands ranging from 44 to 140 years of age in hemi-boreal Estonia. We found three main habitat quality patterns. The total number of fungal OTUs in older (>80 years) stands exceeded that in younger stands due to the accumulation of rare fungi. The proportion of trunks hosting highest number of OTUs and trunk-scale richness of rare fungi were greatest in stands surrounded by extensive forest area. The average number of red-listed species per trunk increased mainly along with the volume of fallen dead wood; large volumes provided quality habitats already before the stands had reached 80 years of age. These results support the view that both substrate amount in the forest stand and habitat connectivity on a landscape scale support fungal diversity in dead wood. Earlier studies on wood-inhabiting fungi have reached similar conclusions based on observations of fungal fruit-bodies. Thus, the overall principle of focusing conservation efforts to remaining high quality habitats and landscapes extends to the fungi hidden to the conventional survey methods. [ABSTRACT FROM AUTHOR]