Behavior in a wide range of choices: substrate preferences of threatened wood-inhabiting species in a mixed old-growth boreal forest
(Oral and Poster)
Ekaterina Shorohova
, Helena Kushnevskaya
, Anna Ruokolainen
, Alexei Polevoi
, Eugene Borovichev
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When everything is available: substrate preferences of threatened wood-inhabiting species in a mixed old-growth boreal forest
In intensively managed forests, many wood-inhabiting species became threatened because of the lack of their habitat - deadwood, especially coarse woody debris (CWD).
We examined a multi-taxon diversity of species associated with fallen logs of Picea abies (22), Betula pubescens, B. pendula (14), Pinus sylvestris (19) and Populus tremula (19) in a chronosequence of decomposition in the old-growth (OG) forest located in the State Strict Nature Reserve 'Kivach', Russia. We hypothesized dynamic and log (tree) species specific patterns for threatened (red-listed and regionally rare species and indicators of OG) wood-inhabiting species.
Insects (only the Hemiptera, Diptera and Coleoptera data are presented) were collected using trunk emergence traps. Fungi (only the agaricoid and aphyllophoroid basidiomycetes data are presented) were recorded based on the repeated inventories of fruitbodies. The epixylic lichens and bryophytes were recorded on all possible log microhabitats. The species distribution patterns were analysed using non-metric multidimensional scaling based on presence/absence data. Log attributes were fitted to the ordination using the vector fitting procedure.
The total (threatened) number of found species was 341(25), 140 (20), 39 (4) and 61 (14) of insects, fungi, macrolichens and bryophytes, respectively. The distribution patterns of threatened species were influenced mainly by the log (tree) species identity (r2=0.55, p<0.001). The next important factors - time since tree death (TTD) (r2=0.19, p=0.009) and cover of feather mosses and vascular plants (r2=0.17, p=0.013) indicated successional status of wood-inhabiting species.
Most threatened insects were associated with aspens fallen one (Aulonothroscus laticollis), seven (Leptura thoracica) or 0-16 (Rhizophagus puncticollis) years ago, or spruces fallen 17-24 years ago (Ceruchus chrysomelinus). Most threatened lichens (Lobaria pulmonaria, Nephroma parile) were associated with aspens fallen 0-25 years ago. Most threatened fungi occurred on conifer, mainly spruce logs fallen 0-25 (Asterostroma laxum, Flaviporus citrinellus, Fomitopsis rosea, Phlebia centrifuga), or more than 45 (Crustoderma corneum, Phellinus viticola, Postia sericeomollis, Rhodonia placenta) years ago or on aspen logs fallen 4-40 years ago (Lentaria afflata, Punctularia strigosozonata and Tomentella crinalis). Most threatened bryophytes preferred spruce logs with the age of 6-25 (Cephalozia macounii, Syzygiella autumnalis, Tritomaria exsecta) or 26-40 (Lophozia ascendens, Scapania apiculata) years.
Thus, aspen and spruce logs in a full range of TTD provided ecological niches for almost all found threatened species. This result provides new implications for biodiversity conservation.
The study is supported by the Russian Science Foundation (15-14-10023).
INTRO: Many wood-inhabiting species became threatened because of the lack of their deadwood habitat. Better understanding of relation of those species to certain CWD attributes is needed for a sound forest management, ecological restoration and nature conservation planning. The authors examined a multi-taxon diversity of species associated with fallen logs of Picea abies, Betula pubescens and B. pendula, Pinus sylvestris and Populus tremula in a chronosequence of decomposition in the middle boreal old-growth forest located in State Strict Nature Reserve 'Kivach', Russia.
MERITS: The study question is highly relevant for practical conservation. The data and methods seem appropriate. Inferences are justified and the abstract is generally well written.
CRITIQUE: It would be good to know how many trunks of each tree species were examined. Because there are already many studies on CWD and associated species, it would have been good if the authors had indicated what is novel or intersting in their study.
DISCUSSION: No particular weaknesses.
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INTRO: This is a multi taxon study of habitat preferences of rare and red listed saproxylic species. The study is performed in a Russian protected area and cover a wide range of tree species and successional stages.
MERITS: This study add important information on the ecology of rare and threatened species. For many such species their ecology and substrate preferences is only known through anecdotical findings. This study add valuable empirical data.
CRITIQUE: I lack information on the total number of species and individuals found. This information is needed to be able to evaluate the results.
DISCUSSION: Information from studies like this can be very valuable for restoration of habitats in managed areas.
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INTRO: This study deals with the distribution of wood-inhabiting species in different types of deadwood substrates in an old growth nature reserve in Russia. The distribution of rare and red-listed species of wood fungi, lichens, bryophytes and insects in different substrate types are analyzed and reported. The results stress the importance of Aspen for red-listed insects and spruce for the other organism groups.
MERITS: The multispecies approach in this study is important and rare. This approach provides a better overview of the importance of different substrate types for saproxylic organisms. The chronosequence approach in this study are also valuable as it provides information on successional patterns of saproxylic organism
CRITIQUE: The abstract lack some basic information regarding the experimental design, e.g. how many substrates were sampled and of what kind. Also it is not clear how red-listed many species that were identified in different taxonomic group. The study is quite descriptive and lacks clear questions/hypotheses. Clearly stated questions/hypotheses would improve readability, help with the interpretation of the results and improve the discussion
DISCUSSION: The conclusion is that the result from the current study concurs with earlier studies and provides limited information regarding novel findings. I think the discussion can be developed further to describe possible novel findings in the study
