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This study investigated the diversity and ecology of deadwood-inhabiting mushrooms in Yankari Game Reserve. Stratified random sampling was used for the data collection. A total of 23 different mushroom species belonging to 12 different families were found growing on deadwood in the study area, with Polyporaceae and Hymenochaetaceae as the most dominant mushroom families. The distribution, composition, and diversity of the different mushroom species differed according to their local habitats, growth substrate and tree species. The habitats with the highest mushroom species diversity were the Lowland Combretaceous Woodland, Pteleopsis habeensis Woodland. Their Shannon Index (H′) values were 2.31 and 1.96 respectively, and Simpson Index (D) values were 6.81 and 4.74, respectively. Their mushroom abundance was significantly (α = 0.05, p = 0.00) higher than that of Afzelia africana Woodland and Upland Combretaceous Woodland. The Main Trunk was the growth substrate with the highest H′ and D, which were 2.11 and 6.32, respectively; while the Branch had a significantly (α = 0.05, p = 0.00) higher abundance of mushrooms than the soil. Pteleopsis habeensis was the tree species that had the highest mushroom species richness and abundance with H′ (2.06) and D (5.07). The P. habeensis had significantly (α = 0.05, p = 0.00) higher mushroom abundance than all the rest of the thirteen different tree species. Trametes pubescens was the most abundant mushroom species, which was significantly (α = 0.05, p = 0.00) higher than the abundance of 10 species other mushroom species found in the study area. The result of this study can help forest managers conserve the diversity of deadwood-inhabiting mushrooms.

Most European forests are used for timber production. Given the limited extent of unmanaged (and especially primary) forests, it is essential to include commercial forests in the conservation of forest biodiversity. In order to develop ecologically sustainable forest management practices, it is important to understand the management impacts on forest-dwelling organisms. Experiments allow testing the effects of alternative management strategies, and monitoring of multiple taxa informs us on the response range across forest-dwelling organisms. To provide a representative picture of the currently available information, metadata on 28 multi-taxa forest management experiments were collected from 14 European countries. We demonstrate the potential of compiling these experiments in a single network to upscale results from the local to continental level and indicate directions for future research. Among the different forest types, temperate deciduous beech and oak-dominated forests are the best represented in the multi-taxa management experiments. Of all the experimental treatments, innovative ways of traditional management techniques (e.g., gap cutting and thinning) and conservation-oriented interventions (e.g., microhabitat enrichment) provide the best opportunity for large-scale analyses. Regarding the organism groups, woody regeneration, herbs, fungi, beetles, bryophytes, birds and lichens offer the largest potential for addressing management–biodiversity relationships at the European level. We identified knowledge gaps regarding boreal, hemiboreal and broadleaved evergreen forests, the treatments of large herbivore exclusion, prescribed burning and forest floor or water manipulations, and the monitoring of soil-dwelling organisms and some vertebrate classes, e.g., amphibians, reptiles and mammals. To improve multi-site comparisons, design of future experiments should be fitted to the set-up of the ongoing projects and standardised biodiversity sampling is suggested. However, the network described here opens the way to learn lessons on the impact on forest biodiversity of different management techniques at the continental level, and thus, supports biodiversity conservation in managed forests.

Achieving an understanding of species’ temporal and spatial abundance patterns is a prerequisite for proper conservation and management decisions. Little is known of the ecological indicators of census size or biomass of terrestrial amphibian communities and historical estimates of population size are rare. Here we took advantage of abundance and biomass data collected in 1967/1968 for a leaf-litter amphibian community in Niepołomice Forest (NF) in south-central Poland. Using the same technique (removal sampling), we censused the amphibian community of this forest 50 years later (2016/2017), spatially matching a subset of current plots with the historical sampling sites. Averaged over all plots, we revealed at least a fourfold decline in amphibian abundance from 2817 ± 776 individuals/ha in 1967 to 674 ± 508 individuals/ha currently, paralleled by a decline in biomass from roughly 15.5 ± 1.7 to 3.8 ± 3.1 kg/ha. The decline was more striking (over 15-fold) for current plots placed in the same forest division as the historical plots (mean counts of 157 ± 103 individuals/ha corresponding in biomass to 1.0 ± 0.5 kg/ha). We also recorded a change in species composition between surveys, and propose that conversion of aquatic habitat and forest succession have decreased amphibian diversity and abundance in NF. Further, we estimated densities of anuran amphibians in forest plots differing in management regime and local habitat characteristics for contemporary plots (all historical plots were placed in managed forest). We found that unmanaged, old growth forest plots with coarse woody debris on the forest floor held on average twice as many anurans compared to plots in managed stands. Average body condition of the most common species, Rana temporaria, measured as a scaled mass index, was enhanced in plots situated in old growth forest. Our findings suggest that the preservation of old growth forests containing coarse woody debris may boost anuran abundance, biomass and body condition, and has the potential to buffer against long-term demographic decline. Moreover, the retention of deadwood could be a means of increasing the conservation potential of managed forests for terrestrial amphibian communities.

In sustainable forest resource management, establishing forest conservation areas is important to maintain forest biodiversity. However, assessing the conservation value of forests is challenging because the target areas are often both large and remote. We explored using dense airborne laser scanning (ALS) data to estimate conservation values. Field data were collected at sites in Sweden for standing deadwood (S trees), laying deadwood (L trees), and trees considered particularly important for conserving biodiversity (N trees), and forest conservation values were determined using a commonly employed method in the field. A template matching method was then used to detect L, S and N trees from ALS data. L trees were identified from linear features in the point cloud above the ground, with a 52 % detection error rate. S and N trees were identified from unusually small or large crown diameters, with 71 % and 83 % error rates, respectively. We also tested the relationships between the three types of indicator tree, their summed values and the field inventory-assessed conservation values. Regressions between the assessed conservation values and ALS indicators were most robust comparing the three test sites when using the summed number of L, S, and N trees. A wall-to-wall map covering a 3 km × 4 km area was generated using Kernel density estimation of the summed number of ALS-derived indicators, to represent relative conservation values. The map was validated using 10 1-ha plots, and yielded an R2 value of 0.6 for predicted conservation values at the plot level. We conclude that ALS data can be used to map forest conservation values and inform decisions about which forests should be used for timber production and which should be set aside as conservation areas. The maps could also be used as a data source for habitat analysis.

Knowledge of habitat requirements of saproxylic insects and their response to habitat changes is critical for assessing the ecological impacts of forest management. Several studies have demonstrated a positive relationship of tree-species richness, deadwood volume, or structural diversity with saproxylic species diversity, while the relationship with the abundance of potential pest species have often been negative. A better understanding of which factors drive saproxylic insects’ occurrence is therefore essential for deriving urgently needed thresholds for key habitat conditions. We tested a rapid assessment method applicable at large scale based on recorded feeding galleries and boreholes assessed during the Austrian National Forest Inventory to investigate the drivers and habitat thresholds of different saproxylic insect families; i.e. Buprestidae, Cerambycidae, Curculionidae, Siricidae, at multiple spatial scales; i.e. at the object, forest stand and landscape level. We modelled the relative abundance of all insects and these families considering nineteen explanatory variables using ordinal logistic regression models. Key habitat characteristics were identified using recursive partitioning. Our results revealed complex interactions among influencing factors at different spatial scales. We showed that deadwood volume was of surprisingly little importance. Instead, individual tree characteristics were of major importance, demonstrating the value of resource quality and variability. The abundance of all saproxylic insect families increased with advancing decomposition, on trees taller than 18 m, and above a living stand volume of 41 m3ha−1. Aiming to guide forest management, not only forest type-specific, but tree species-specific deadwood management is needed, taking into account site-specific conditions, including temperature and precipitation. For assessing temporal trends in insect colonization and habitat dynamics as well as the effects of forest management, we propose a continuous monitoring of insect traces, including living but weakened trees. This will allow for further thresholds that are urgently needed for maintaining biological diversity in forest ecosystems in the face of climate change.

Although species composition, species diversity and the frequency of epixylic bryophytes is quite well recognised in Central Europe, the patterns associated with their plant traits are still relatively unknown. The main objective of this study was to determine which plant traits best explain the colonization of coarse woody debris (CWD) by the bryophytes and associate them with environmental factors. Moreover, we wanted to examine whether there are internal guilds of epixylic liverworts and mosses based on their plant traits. The research was performed in both protected and managed forests in the Karkonosze Mts (southern Poland). A total of 574 pieces, i.e., fallen logs, were randomly selected. Fifteen environmental factors, i.e., the properties of the CWD, including the decomposition scale, moisture, the length of a log, climatic factors and the species identity of the trees were selected. In addition, statistical analyses of twenty plant traits, primarily the life-forms, habitat requirements and the types of reproduction of 96 bryophyte species were performed. According to the three-table ordination method (RLQ), 42 significant associations between the plant traits and environmental variables were recorded. The differences in the variations in the plant traits were associated with the host tree (beech Fagus sylvatica vs spruce Picea abies). The species that prefer a more nutrient-rich substratum and more alkaline environment were correlated with beech logs, whereas the species that prefer a higher moisture content were correlated with spruce logs. The plants that were characterised by creeping and erect lateral branches were associated with logs with a higher bark cover at the lower altitudes and were found mostly on beech logs. Dioecious and tuft plants avoided long logs, whereas monoecious plants preferred them. The rare and protected species were confined to the higher altitudes, less bark cover and smaller logs. Three guilds of epixylic bryophytes were distinguished that differed in 12 plant traits. Although their occurrence seemed to be confined to the specific phases of the decomposition of deadwood, these findings need to be tested on a larger dataset.

Riparian forests are among the most dynamic but threatened terrestrial ecosystems. Their dynamism and conservation depend on historical changes in river geomorphology, which can be evaluated through changes in channel sinuosity. However, we lack long-term assessments on sinuosity and how they impact riparian forest composition, tree growth and deadwood amount. To fill this research gap, we reconstructed river sinuosity in 14 sites across the middle Ebro basin, north-eastern Spain, using historical aerial photographs taken in 1927, 1956, 1998-2003 and 2014-2015. Relationships between sinuosity, stand composition and deadwood amount and decay degree were calculated. We also reconstructed radial growth of the major tree species (Populus alba, Populus nigra, Fraxinus angustifolia, Salix alba and Ulmus minor) in two sites to evaluate how coupled it was with changes in river flow after dam building. From 1927 to 2015, sinuosity decreased passing from 1.39 to 1.20. The river dynamics were altered in the 1950s and 1960s after dam and dyke building. Sites with high sinuosity values in 1956 corresponded to mature stands with large P. nigra individuals. Sinuosity was negatively related to F. angustifolia (r s  = -0.83, p < 0.001) and P. alba (r s  = -0.64, p = 0.02) abundance, whereas sites dominated by P. alba and U. minor presented abundant decayed deadwood. A loss of sinuosity and a contraction of the riverbank gradient increased disconnection of active channel from floodplain, with a mixing of more (e.g., P. nigra) and less phreatophytic species (e.g., U. minor). River flow diversion reduced growth and increased the tree-to-tree P. alba growth coherence. Hydrological droughts contributed to growth decline and dieback of U. minor, which is sensitive to spring river flow. Conservation and restoration of riparian forests must consider historical changes in river geomorphology related to human activities., Competing Interests: Declaration of competing interest Authors declare no conflict of interest., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

The aim of our research was to determine the role of heavily decomposed deadwood in the shaping of accumulation of polycyclic aromatic hydrocarbons (PAHs) in mountain forest ecosystems. The study included heavily decomposed spruce wood located in lower and higher mountain locations (600 and 1200 m a.s.l.) and at the south (S) and north (N) exposure. The accumulation of PAHs in deadwood was compared to the accumulation of PAHs in surface soil horizons in the immediate vicinity of decaying wood and in soils unaffected by decaying wood. Basic chemical properties and enzymatic activity were determined in wood and soil samples. The conducted research indicates the importance of decaying wood for the formation of PAHs accumulation in mountain forest soils. The lowest content of PAHs was recorded in samples of heavily decomposed wood, which at the same time was characterized by the highest enzymatic activity. Significantly higher PAHs content was recorded in soils unaffected by components released from decaying wood. Our research confirmed the importance of location conditions (exposure, altitude) in shaping PAHs accumulation. The highest mountain locations (1200 m a.s.l.) to N exposure were characterized by the highest accumulation of PAHs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Climate change-induced mortality of trees is a concerning phenomenon for global forest ecosystems. The rapid decay and death of long-lived trees can significantly impact forest dynamics, with effects that transmit through ecological networks, becoming more evident in organisms occupying high trophic levels, such as large and specialized woodpecker species. However, understanding how populations of high trophic level species respond to climate change is still a challenge. In this study it was analyzed 32-year data of social groups of the Magellanic Woodpecker (Campephilus magellanicus) in North Patagonia, a region facing increasingly frequent droughts and increased temperatures. A positive trend in the size of woodpecker social groups as a response to climate-induced tree senescence was tested. A causal structural equation model examining climate- tree senescence- woodpecker relationships was used. Increasing nonlinear trends and positive interannual growth rates (>10%) for tree senescence and group size were found. Lowland forest sites had higher levels of tree senescence and more numerous social groups. The causal model supported the positive effect of mean temperature on tree senescence and the positive association of woodpeckers with tree senescence. These results provide evidence of a climate-induced increase in tree senescence that causes an increase in the size of woodpecker social groups. It is suggested that accelerated decay and mortality of trees in the northern Patagonian forests will decrease the stocks of deadwood in the long term, threatening the persistence of this large woodpecker species., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Accurate assessment of tropical peat forest carbon stocks and impact of fires on carbon pools is required to determine the magnitude of emissions to the atmosphere and to support emissions reduction policies. We assessed total aboveground carbon (AGC) in biomass pools including trees, shrubs, deadwood, litter and char, and peat carbon to develop empirical estimates of peat swamp forest carbon stocks in response to fire and disturbance. In contrast to the common assumption that peat fires combust all AGC, we observed that about half of undisturbed forest AGC, equivalent to about 70 Mg C ha -1 , remains after one or two recent fires - mainly in dead trees, woody debris and pyrogenic carbon. Both recently burnt and repeatedly burnt peat forests store similar amounts of carbon in the top 10 cm of peat when compared with undisturbed forests (70 Mg C ha -1 ), mainly due to increased peat bulk density after fires that compensates for their lower peat C%. The proportion of fuel mass consumed in fire, or combustion factor (CF), is required to make accurate estimates of peat fire emissions for both AGC and peat carbon. This study estimated a CF for AGC (CF AGC ) of 0.56, comparable to the default value of the Intergovernmental Panel on Climate Change (IPCC). This study estimated a varying CF for peat (CF PEAT ) that ranged from 0.4 to 0.68 as depth of burn increased. This revised CF PEAT is one third to one half of the IPCC default value of 1.0. The current assumption of complete combustion of peat (CF = 1.0) is widely acknowledged in the literature as oversimplification and is not supported by our field observations or data. This study provides novel empirical data to improve estimates of peat forests carbon stocks and emissions from tropical peat fires., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Tropical peatlands are areas of high carbon density that are important in biosphere-atmosphere interactions. Drainage and burning of tropical peatlands releases about 5% of global greenhouse gas (GHG) emissions, yet there is great uncertainty in these estimates. Our comprehensive literature review of parameters required to calculate GHG emissions from burnt peat forests, following the international guidelines, revealed many gaps in knowledge of carbon pools and few recent supporting studies. To improve future estimates of the total ecosystem carbon balance and peatfire emissions this study aimed to account for all carbon pools: aboveground, deadwood, pyrogenic carbon (PyC) and peat of single and repeatedly burnt peat forests. A further aim was to identify the minimum sampling intensity required to detect with 80% power significant differences in these carbon pools among long unburnt, recently burnt and repeatedly burnt peat swamp forests. About 90 Mg C ha -1 remains aboveground as deadwood after a single fire and half of this remains after a second fire. One fire produces 4.5 ± 0.6 Mg C ha -1 of PyC, with a second fire increasing this to 7.1 ± 0.8 Mg C ha -1 . For peat swamp forests these aboveground carbon pools are rarely accounted in estimates of emissions following multiple fires, while PyC has not been included in the total peat carbon mass balance. Peat bulk density and peat carbon content change with fire frequency, yet these parameters often remain constant in the published emission estimates following a single and multiple fires. Our power analysis indicated that as few as 12 plots are required to detect meaningful differences between fire treatments for the major carbon pools. Further field studies directed at improving the parameters for calculating carbon balance of disturbed peat forest ecosystems are required to better constrain peatfire GHG emission estimates., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Deadwood decomposition is a complex and dynamic process with large implications for biogeochemical cycling of carbon (C) and nitrogen (N) in forest soil and litter. Moreover, it affects functional and structural diversity of fungal and bacterial communities in these components. Mesocosms with deadwood blocks at progressive decay classes were set in a black pine forest and incubated for 28 months in the field with the aim to assess the impact of deadwood decomposition on i) CO 2 , CH 4 and N 2 O fluxes; ii) C and N pools and allocation among deadwood, litter and soil; iii) the fungal and bacterial structural diversity and activity. CO 2 , CH 4 and N 2 O fluxes from deadwood were monitored throughout the field incubation; deadwood biomass loss and decay rate for each decay class were calculated. The stock of C and N, enzyme activities, fungal and bacterial communities in deadwood, litter fractions (fresh, fragmented and humified) and soil at two depths were measured. Emissions of CO 2 and CH 4 increased over the deadwood decomposition advancement and the decay reached the maximum rates in the last decomposition classes. N 2 O fluxes were low and showed either production (prevalent in the first year) or consumption. Independent of the decay class, 20% of C stored in deadwood was lost as CO 2 in the atmosphere, whereas 32% was transferred to the fragmented and humified litter fractions in the last decay class. A corresponding increase of cellulose and hemicellulose degrading enzymes was found in deadwood, also favored by substrates accessibility through fragmentation and successional changes in fungal and bacterial communities. Deadwood, litter fractions and soil components were clearly distinguished in terms of chemical and microbiological properties and activities. Fragmented and humified litter fractions were the only components responsive to the advanced stage of deadwood decomposition, being directly affected by the physical redistribution of fragmented organic matter., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)