Effects of local forest continuity on the diversity of fungi on standing dead pines

This is a self-archived version of an original article. This version may differ from the original in pagination and typographic details. Author(s): Title: Year: Version: Copyright: Rights: Rights url: Please cite the original version: CC BY-NC-ND 4.0; CC BY-NC-ND 4.0 https://creativecommons.org/licenses/by-nc-nd/4.0/; https://creativecommons.org/licenses/by-nc-nd/4.0/ Effects of local forest continuity on the diversity of fungi on standing dead pines © 2017 Elsevier B.V. Accepted version (Final draft) Saine, Sonja; Aakala, Tuomas; Purhonen, Jenna; Launis, Annina; Tuovila, Hanna; Kosonen, Timo; Halme, Panu Saine, S., Aakala, T., Purhonen, J., Launis, A., Tuovila, H., Kosonen, T., & Halme, P. (2018). Effects of local forest continuity on the diversity of fungi on standing dead pines. Forest Ecology and Management, 409, 757-765. https://doi.org/10.1016/j.foreco.2017.11.045 2018 EFFECTS OF LOCAL FOREST CONTINUITY ON THE DIVERSITY OF FUNGI ON1STANDING DEAD PINES2 3Saine Sonja1*, Aakala Tuomas2, Purhonen Jenna1, Launis Annina3, Tuovila Hanna1, Kosonen Timo4 4& Halme Panu1 5 61Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-7 40014 University of Jyväskylä, Finland.8 2Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of9 Helsinki, Finland.10 3Botany unit, Finnish Museum of Natural History, P.O. Box 7, FI-00014 University of Helsinki,11 Finland.12 4Herbarium, Biodiversity Unit, University of Turku, FI-20014 Turku, Finland.13 14 * Corresponding author15 Address: Department of Biological and Environmental Science, University of Jyväskylä, P.O.16 Box 35, FI-40014, Finland.17 Email: [email protected] 19 ABSTRACT20 Human-induced fragmentation affects forest continuity, i.e. availability of a suitable habitat for the target21 species over a time period. The dependence of wood-inhabiting fungi on landscape level continuity has been22 well demonstrated, but the importance of local continuity has remained controversial. In this study, we23 explored the effects of local forest continuity (microhabitat and stand level) on the diversity of wood-24 inhabiting fungi on standing dead trunks of Scots pine (Pinus sylvestris L.). We studied species richness and25 community composition of decomposers and Micarea lichens on 70 trunks in 14 forests in central Finland26 that differed in their state of continuity. We used dendrochronological methods to assess the detailed history27 of each study trunk, i.e. the microhabitat continuity. The stand continuity was estimated as dead wood28 diversity and past management intensity (number of stumps). We recorded 107 species (91 decomposers, 1629 Micarea lichens), with a total of 510 occurrences. Using generalized linear mixed models, we found that30 none of the variables explained decomposer species richness, but that Micarea species richness was31 positively dependent on the time since tree death. Dead wood diversity was the most important variable32 determining the composition of decomposer communities. For Micarea lichens, the community composition33 was best explained by the combined effect of years from death, site and dead wood diversity. However, these34 effects were rather tentative. The results are in line with those of previous studies suggesting the restricted35 significance of local forest continuity for wood-inhabiting fungi. However, standing dead pines that have36 been available continuously over long periods seem to be important for species-rich communities of Micarea37 lichens. Rare specialists (e.g. on veteran trees) may be more sensitive to local continuity, and should be at the38 center of future research.39 40 Keywords: dead wood continuity, decomposer, Micarea, microhabitat continuity, Pinus sylvestris L., stand41 continuity42 1. INTRODUCTION43 Intensive forestry activities have led to severe forest fragmentation throughout the globe (Riitters et44 al., 2000). The spatial aspects of fragmentation, such as decreased habitat amount, size, and45 connectivity are well known for a negative effect on biodiversity and ecosystems (Bengtsson et al.,46 2000; Fahrig, 2003). Temporal aspects of fragmentation, such as decreased habitat continuity, have47 been studied less than the spatial aspects, but have similarly been shown to have negative impacts48 on biodiversity (Nordén et al., 2014).49 Forest continuity can be considered at local level where it relates to longevity of a single,50 available patch of suitable habitat for the target species or community, and where the scale of51 habitat patch is equivalent to one local population (Hanski, 2005; Nordén et al., 2014). With higher52 local continuity, higher species richness and larger variety of specialist species can occur as the53 colonization and/or breeding probability of species with establishment constraints, slow rates of54 establishment, development, or growth is enhanced (Esseen et al., 1997; Fritz et al., 2008; Nilsson55 and Baranowski, 1997; Nordén et al., 2014). The cause for higher species richness and larger56 variety of specialists may also be the emergence of special microhabitat types confined to late57 successional phases or larger diversity of different microhabitats. This is due to the absence of58 large-scale disturbances, which promotes the time-demanding development of these resources59 (Tibell, 1992; Sverdrup-Thygeson, 2001; Winter and Möller, 2008). Landscape level continuity, on60 the other hand, refers to a network of available habitat patches within a given region or landscape61 over time (Fritz et al., 2008; Hanski, 2005; Nordén et al., 2014). Here, the role of dispersal62 limitations increases when the landscape level continuity decreases (Nordén and Appelqvist, 2001).63 Wood-inhabiting fungi are among the organism groups suffering most from the decreased64 landscape level forest continuity caused by fragmentation (Nordén et al., 2014; Flensted et al.,65 2016). The importance of this landscape level continuity for wood-inhabiting fungal diversity has66 been well demonstrated (Flensted et al., 2016; Gu et al., 2002; Junninen and Komonen, 2011; Paltto67 et al., 2006; Ranius et al., 2008; Sverdrup-Thygeson and Lindenmayer, 2003). Apparently, the68 biological reason for this dependence is that some species of wood-inhabiting fungi are in fact69 dispersal limited (e.g. Norros et al., 2012), although species dependent on ephemeral habitats have a70 high dispersal ability in general (Herben et al., 1991).71 The role of local continuity has remained less clear, compared to landscape level continuity.72 Stokland and Kauserud (2004) suggested that a polypore Phellinus nigrolimitatus cannot effectively73 colonize suitable trunks when the stand level dead wood continuity decreases. With epiphytic74 lichens, forest age and continuity appear to have a positive effect on their species richness and75 affect their community composition (Fritz et al., 2008). Also here, the increased colonization76 probability with increasing forest age and continuity was considered as the most probable77 explanation. On the other hand, several studies have detected no effects of local continuity (Groven78 et al., 2002; Rolstad et al., 2004; Sverdrup-Thygeson and Lindenmayer, 2003), and many studies79 have been criticized for not demonstrating the effect of continuity per se (Nordén and Appelqvist,80 2001; Nordén et al., 2014).81 In their review, Junninen and Komonen (2011) deduced that boreal polypores are not affected82 by continuity on a stand scale in any way, and Nordén et al. (2014) concluded that local continuity83 does not have a significant effect on the diversity of fungi. Nevertheless, this generalization may be84 misleading; fungi encompass species with divergent ecological characteristics, with many of the85 species being habitat specialists, requiring dead wood in advanced stages of decay (Nordén et al.,86 2013). Moreover, studies have not focused on the smallest scale of local continuity, i.e. the detailed87 history of the microhabitats. Especially the standing dead coniferous trees may retain their qualities88 for decades, and therefore constitute a microhabitat with potentially high continuity. Considering89 ephemeral habitats in general, standing dead coniferous trees may be among the slowest constantly90 changing microhabitats (compared to more persistent abiotically determined microhabitats, such as91 those in soil).92 In this study, we explored the effects of local forest continuity (microhabitat and stand level)93 on the communities of wood-inhabiting fungi. We studied fungal communities on standing dead94 wood of Scots pine (Pinus sylvestris L., hereafter pine) in 14 forests with varying state of95 continuity. We used trunk age parameters as estimates for microhabitat continuity, and estimated96 stand continuity as dead wood diversity and past management intensity. We focused on pine97 because the species is characterized by slow death and decay process (Niemelä et al., 2002;98 Siitonen, 2001). Specifically, we asked:99 1. How does local forest continuity affect i) species richness and ii) community composition100 of wood-inhabiting fungi inhabiting standing dead pines?101 2. How different scales of continuity (from microhabitat continuity to stand continuity)102 affect i) species richness and ii) community composition?103 3. Are the effects of local continuity different for different fungal groups?104 105 2. MATERIALS AND METHODS106 2.1. Study sites and trunk selection107 Our 14 study forests (Table 1) were located in central Finland (Fig. 1), 12 of them being in the108 southern boreal zone, and two in the middle boreal zone (Ahti et al., 1968). In each forest, the study109 trunks were selected on a 10-m wide transect. Each transect was established 15 meters from the110 point of easiest access into the study stand. The direction of the transect was towards the center of111 the stand, except in smaller stands (< 100 m wide) where the transect followed the direction of the112 longest side of the stand. If the opposite side of a stand was met before trunks were surveyed, the113 transect was turned around and continued parallel to the first transect. The first five pine trunks114 within a transect that fulfilled the criteria of being 1) standing (leaning max. 45°) and dead, 2)115 trunks or high stumps (³ 0.5 m in height), and 3) ³ 7 cm in diameter, were selected for sampling.116 Table 1. Site information. Dominant tree species and mean age classes are derived from Natural Resources117 Institute Finland, 2015.118 Site Municipality Dominant tree species Mean age class 1 Hallinmäki Jämsä spruce 96–132 2 Ilmakkamäki Suonenjoki pine 56–65 3 Kalaja Rautalampi pine 62–71 4 Kirkkokangas Muurame spruce 85–109 5 Kivetty Äänekoski spruce 72–84 6 Kotinen Hämeenlinna spruce 75–89 7 Kuusimäki Muurame spruce 45–55 8 Latokuusikko Kuhmoinen spruce 88–108 9 Leivonmäki Joutsa pine 62–78 10 Lortikka Kuhmoinen spruce 70–80 11 Pyhä-Häkki Saarijärvi pine 101–144 12 Vaarunvuoret Jyväskylä spruce 62–72 13 Vesijako Padasjoki spruce 54–63 14 Vuorilampi Toivakka pine 45–55 119 120 Fig. 1. The map showing the regions of Finland and the locations of the study sites. Site names are presented121 in Table 1. © National Land Survey of Finland 2016, 2017. [1.5-column fitting image]122 123 2.2. Data collection and preparations124 2.2.1. Species data125 All decomposer fungi and Micarea lichens were recorded from each study trunk based on the126 occurrence of fruit bodies. Sampling of Micarea and Mycocaliciales species was conducted in three127 parts: October 2014, May–June 2015, and September 2015. Rest of the groups (agarics, corticioids,128 discomycetes, jelly fungi, polypores, and pyrenomycetes) were sampled in separate surveys in129 August–September 2015. Agarics were sampled again during October 2015 to meet a better share130 of a local species community (their detectability is lower than in other groups, see Abrego et al.131 (2016) and Purhonen et al. (2016)). The trunks were carefully examined throughout from ground132 level up to a height of 1.8 meters. Species of Mycocaliciales were recorded only from sapwood, all133 other fungal groups also from bark. Fungi were identified to species in the field if possible.134 Otherwise, specimens were taken for later microscopical identification in the laboratory. Species135 nomenclature followed Coppins (1983), Czarnota (2007), and Czarnota and Guzow-Krzemínska136 (2010) with Micarea species, Tibell (1999) with species of Mycocaliciales, and Index Fungorum137 (Royal Botanic Gardens Kew et al., 2016) with the rest. If possible, identifications were made to138 species level, otherwise to genus level.139 In the analyses, we used species level identifications. We also included genus level140 identifications that were different from the identified species of the same genus. We have141 thoroughly aimed at a similar taxonomic resolution throughout the data. In the case of142 taxonomically very poorly known groups of Chaenothecopsis and Mycocalium, several undescribed143 species were separated based on spore size, type and some other anatomical and chemical144 characters, and considered as distinct species. Also, some pyrenomycetes remained unidentified, but145 when it was possible to separate them from the rest of the detected species, they were considered as146 species in the analyses.147 148 2.2.2. Study trunk specific measures149 Several variables were recorded for each study trunk in the field. These included coordinates,150 circumference at breast height (cm), height (m), decay stage (1–5), the proportion of surface not151 covered by bark (%) and the coverage of lichens (%). The circumference at breast height was152 converted to diameter, and it was used as an estimate of survey effort.153 We also estimated the canopy openness around the trunks. Four fisheye photos were taken154 towards principal compass points while standing back against the trunk. The proportion of visible155 sky was calculated from each photo, using ImageJ (version 1.45s; Schneider et al., 2012). The final156 estimate for canopy openness was the mean of these four, trunk specific values.157 158 2.2.3. Age and time since death of study trunks159 We assigned each study trunk age and time since death, using dendrochronological methods. From160 each trunk, we extracted a cross-sectional sample disc, or a partial disc. When possible, the samples161 were extracted from the part of the trunk where bark was still present, to ensure we had the last162 growth ring. When bark or bark remnants were no longer present, we extracted the sample from163 where we subjectively estimated minimum ring erosion. In addition to the study trunks, we further164 extracted increment cores from five live trees within the vicinity of the study trunks at each site, for165 building a master chronology. In the laboratory, the samples were first dried, increment cores166 mounted to core mounts, and frail sample discs reinforced following Krusic and Hornbeck (1989;167 but in normal air pressure). Samples were sanded to make annual rings and ring borders clear and168 easily observable.169 Tree rings were dated, using visual cross-dating (Yamaguchi, 1991), against the site-specific170 marker rings obtained from the live trees. The widths of the tree-rings in all samples were measured171 using WinDENDRO (Regent Instruments Inc., 2015), and the visual cross-dating results were172 statistically confirmed, using the COFECHA-software (Holmes, 1983). If the pith of the tree was173 missing (necessary for estimating the year of recruitment), we estimated the number of missing174 rings, using a pith locator (Speer, 2010).175 The tree age at death (AAD) was calculated as the difference between the calendar year of the176 last ring, and the pith year. The years from death (YFD) was calculated as the difference between177 the sampling year (2015) and the cross-dated year of the last ring. In general, only trunks for which178 since tree death increased towards the upper right corner of the ordination space (Fig. 3d), and dead304 wood diversity increased towards the lower right corner of the ordination space (Fig. 3c). However,305 as adding site increased the correlation between the community dissimilarities and environmental306 distances, the effect of years from death and dead wood diversity is not independent of site. The307 final stress level for the two-dimensional NMDS solution in Fig. 3c and 3d was 0.175. Altogether,308 the results for both decomposers and Micarea lichens should be interpreted with caution due to the309 low correlations in the Bioenv analyses.310 Table 4. Results from Bioenv analyses of environmental variables affecting community composition of311 decomposers and Micarea lichens. Correlations are Spearman rank correlations between the community312 dissimilarities and environmental distances. Abbreviations: DW = dead wood, YFD = years from death,313 AAD = age at death, Stumps = management intensity, Canopy = canopy openness.314 315 Decomposers Size Variables Correlation 1 DW diversity 0.12 8 2 DW diversity, YFD 0.120 3 DW diversity, YFD, Site 0.109 4 DW diversity, YFD, Site, Diameter 0.099 5 DW diversity, YFD, Site, Diameter, AAD 0.078 6 DW diversity, YFD, Site, Diameter, AAD, Stumps 0.049 7 DW diversity, YFD, Site, Diameter, AAD, Stumps , Canopy -0.011 Micarea lichens Size Variables Correlation 1 YFD 0.126 2 YFD, Site 0.168 3 YFD, Site, DW diversity 0.195 4 YFD, Site, DW diversity, Stumps 0.177 5 YFD, Site, DW diversity, Stumps, AAD 0.160 6 YFD, Site, DW diversity, Stumps, AAD, Canopy 0.142 7 YFD, Site, DW diversity, Stumps, AAD, Canopy, Diameter 0.081 Fig. 3. NMDS representing the differences in community structure between the communities of decomposers316 (a–b; circles) and Micarea lichens (c–d; triangles) observed in the study. One symbol represents one317 community occurring on one trunk. The size of a symbol represents the magnitude of dead wood diversity in318 Fig. 3a and 3c, and the number of years from death in Fig. 3b and 3d. The size of a symbol grows with319 increasing values of the variables. Stress level for both solutions is 0.175. [2-column fitting image]320 321 In our analyses on the 14 individual species, four species were statistically significantly322 affected by some of the variables (Table B.1 in Appendix B). Local continuity explained the323 presence of the species both positively and negatively. For the rest, the final models did not include324 any statistically significant variables. All results considering individual species are presented in325 Appendix B.326 327 4. DISCUSSION328 4.1. Effects of stand continuity329 Decomposers and Micarea lichens were affected by stand continuity through modest changes in the330 community composition that were driven by dead wood diversity. Communities of decomposers331 were more similar among sites with low dead wood diversity and differentiated when dead wood332 diversity increased. This might be because the communities in sites with low dead wood diversity333 might have more shared generalist species, able to survive in sites with more homogenous dead334 wood resources and thus, occurring more evenly across the landscapes (Nordén et al., 2013). With335 increasing dead wood diversity, sites can host more unique species assemblages including also336 specialists (Abrego and Salcedo, 2013; Nordén et al., 2013). Similar, although weaker trend337 occurred with Micarea lichens.338 The species richness of decomposers or Micarea lichens was not affected by dead wood339 diversity or management intensity. Increased dead wood diversity should contribute to a higher340 amount of available resources and niches (Siitonen, 2001; Stokland et al., 2012), and its positive341 effect on species richness of wood-inhabiting fungi has been demonstrated in previous studies (e.g.,342 Hottola et al., 2009; Penttilä et al., 2004; Similä et al., 2006). Also, the negative effects of343 management intensity have been widely reported (e.g., Arnstadt et al., 2016; Bader et al., 1995).344 In studies where all dead wood diversity (including also different tree species) has been345 measured to reflect the stand continuity, and the species richness has been measured from all of the346 material contributing to the dead wood diversity, it is very logical that clear positive correlations347 occur between species richness and stand continuity (see for example Hottola et al., 2009; Penttilä348 et al., 2004; Similä et al., 2006). Thus, it is worth emphasizing that as we measured only the dead349 wood diversity of pine, and recorded the fungal species richness only from the selected standing350 dead trees, such correlation might be more difficult to find. However, we argue that if such a351 correlation would be found it would truly reflect the species dependence on stand continuity, not352 just that more diverse substrate pool has more diverse species pool.353 Species interactions might also play its part in the absence of a positive relationship between354 species richness and stand continuity. Heilmann-Clausen and Christensen (2005) found that the355 species richness of wood-inhabiting fungi on an individual tree was negatively affected by dead356 wood continuity (estimated as the proportion of strongly decayed logs). They suggested competitive357 exclusion to be one of the possible explanations: highly competitive specialists replace the early358 successional, non-specialist species in sites with high dead wood continuity. Thus, the species359 richness it not necessarily higher in the high continuity stands compared to stands with lower360 continuity, but can show no trends or even be lower.361 In addition, the sites were located in or in the vicinity of conservation areas and thus, at least362 some natural forests were located in the proximity of sites. The variation in dead wood diversity and363 management intensity might not have been sufficient to reveal all existing trends. Moreover,364 management intensity of the sites was relatively low compared to the average managed forests in365 the area. In a study by Penttilä et al. (2004), dead wood diversity and management intensity induced366 a clear trend in polypore community composition when they compared communities in managed367 and old-growth forests. They recorded 400–500 stumps in managed stands, whereas the most368 managed site in this study included only 112 cut stumps per hectare.369 The fact that stand continuity did not have a strong effect on decomposers and Micarea370 lichens gives indirect evidence that they are not dispersal limited at such fine spatial scales. In fact,371 it has been suggested that pine inhabiting fungi would be less affected by forest management than372 species specialized in e.g. spruce due to their better dispersal abilities (Stokland and Larsson, 2011).373 Stokland and Larsson (2011) hypothesized that this could be due to the different selection pressures374 in pine forests that experience forest fires and have lower input rates of dead wood than spruce375 forests. Thus, the sites may support viable metacommunities of these pine-inhabiting species if376 landscape level continuity is high. However, on rare specialist species, dispersal limitations might377 occur already at small spatial scales (Norros et al., 2012).378 379 4.2. Effects of microhabitat continuity380 Micarea species richness increased with time since tree death. Microhabitat continuity could be381 more important for Micarea lichens than stand continuity due to their slow rates of growth and382 establishment (Nordén et al., 2014; Stenroos et al., 2011). With increasing time since tree death383 there is more time available for colonization (Johansson et al., 2007), and new suitable384 microhabitats, such as decorticated wood appear (Renvall, 1995). The result also fits well with the385 hypothesis of species time relationship (Rosenzweig, 1995), especially because competitive386 exclusion has been suggested to be rare in lichens (Lawrey, 1991; Uliczka and Angelstam, 1999).387 Species richness of decomposers was not affected by time since tree death. Previous studies388 have demonstrated an increase in species richness of wood-inhabiting fungi from initial decay389 stages to intermediate ones (Arnstadt et al., 2016; Renvall, 1995), and with time since tree death390 (Heilmann-Clausen, 2001). This pattern could result from changes in the tree quality (e.g. bark391 exfoliation (Renvall, 1995), and decreasing wood density in standing dead trees (Saint-Germain et392 al., 2007)), and from the emergence of late successional species (Høiland and Bendiksen, 1997). In393 the present study, the trunks with the longest time since their death probably included many kelo394 trees, i.e. standing dead trees characterized by slow death that makes the trunk very resistant to395 decay (Niemelä et al., 2002). Since kelos are utilized by a limited set of specialist species (Niemelä396 et al., 2002; Stokland et al., 2012), species richness might not increase linearly with time.397 Additionally, increasing competition with increasing habitat patch age might explain our result398 (Nordén and Appelqvist, 2001).399 Community composition of both decomposers and Micarea lichens was slightly dependent on400 time since tree death. Communities on recently died trunks probably share certain (pioneer) species401 that inhabit the freshly dead wood (Niemelä et al., 1995; Renvall, 1995). Later on, fungal402 succession takes place with proceeding decomposition (Rajala et al., 2012; Stokland et al., 2012)403 and thus, different species of wood-inhabiting fungi should occur at different times after the tree404 death (Niemelä et al., 1995; Heilmann-Clausen, 2001). Trends in the community composition could405 have been stronger if more trunks at the end of the decomposition range could have been included406 in the analyses. The trunks for which the year of death could not be determined due to the erosion407 of the outermost tree rings were likely the oldest but had to be excluded from our analyses.408 Tree age at death did not affect either of the studied fungal groups. This indicates that it might409 be important only for few species if any. The opposite was hypothesized as, for example, the410 community composition of dead wood might be affected by the longevity of infection history411 during the tree lifespan (Heilmann-Clausen and Christensen, 2004). Similar to the tree age at death,412 trunk diameter did not affect the communities of wood-inhabiting fungi. Several studies focusing on413 downed dead wood have reported the opposite (e.g., Høiland and Bendiksen, 1997; Renvall, 1995).414 However, our results are in accordance with the results by Pouska et al. (2016a) that showed no415 effect of diameter on wood-inhabiting fungal communities on standing dead Norway spruces. They416 suggested that diameter interacts with several other, more important trunk characteristics (e.g. trunk417 temperature and moisture) than diameter per se.418 Also canopy openness did not affect wood-inhabiting fungal communities. Sun exposure may419 affect community composition of wood-inhabiting fungi (Heilmann-Clausen, 2001), and lichens420 have been shown to respond positively to increasing canopy openness (Marmor et al., 2012;421 Uliczka and Angelstam, 1999). Our results could be explained by milder edge effect in natural422 forest edges (Ruete et al., 2016) that were characteristic for our study sites. Moreover, canopy423 openness might be positively related to stand age, and thus light availability would not limit lichen424 communities in older stands (Bäcklund et al., 2016).425 426 4.3. Conclusions427 In the conservation areas of central Finland, wood-inhabiting fungal diversity was not significantly428 affected by local forest continuity. The results indicate that on a stand scale, other environmental429 filters and stochastic processes underlie the patterns of wood-inhabiting fungal diversity on standing430 dead pines. Although some species would depend on the continuous supply of dead wood and old431 trees, they seem not to be limited by dispersal, and can find these suitable habitats within the432 surrounding landscapes, underlining the importance of landscape level continuity.433 The results demonstrated the importance of old, standing dead trees for species-rich434 communities of Micarea lichens. Conservation strategies concerning these species should aim to435 increase the local number of old trees that die and decay naturally. To achieve this, approaches of436 retention forestry should be applied in managed forests (Gustafsson et al., 2012; Lindenmayer et al.,437 2012). However, increasing the number of veteran trees in forest landscapes requires extending the438 time-frames of strategies that are currently applied in forest management (Lindenmayer et al.,439 2014).440 The explicit relationship between local continuity and rare species remained unsolved. These441 species might be more sensitive to local continuity than common species when taking into442 consideration e.g. their highly specialized habitat use (Nordén et al., 2013). Therefore, rare and red-443 listed species should be at the center of future research on local continuity to be able to guide the444 required conservation actions, and to maintain these species also locally.445 446 ACKNOWLEDGEMENTS447 We would like to thank field assistants Meeri Väätäinen and Tapio Envall who helped with the data448 collection, Heikki Kotiranta who identified the difficult specimens of corticioid fungi, and Anna449 Oldén who provided statistical help. We are grateful to Dr. Fredericksen and an anonymous450 reviewer for constructive comments on an earlier version of the manuscript. The study was funded451 by the Ministry of the Environment (PUTTE grant to Halme and Leena Myllys), Societas Biologica452 Fennica Vanamo (grant to Saine), Societas pro Fauna et Fennica (grant to Saine), and the University453 of Helsinki Funds (grant to Aakala).454 455 APPENDIX A. Supplementary tables (Table A.1–A.3).456 APPENDIX B. Responses of individual species457 458 REFERENCES459 Abrego, N., Salcedo, I., 2013. Variety of woody debris as the factor influencing wood-inhabiting fungal460 richness and assemblages: Is it a question of quantity or quality? For. Ecol. Manage. 291, 377–385. doi:461 http://dx.doi.org/10.1016/j.foreco.2012.11.025462 Abrego, N., Halme, P., Purhonen, J., Ovaskainen, O., 2016. Fruit body based inventories in wood-inhabiting463 fungi: Should we replicate in space or time? Fungal Ecol. 20, 225–232.464 doi:10.1016/j.funeco.2016.01.007465 Ahti, T., Hämet-Ahti, L., Jalas, J., 1968. Vegetation zones and their sections in northwestern Europe. Ann.466 Bot. 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