•Our review linked 44 biodiversity indicators with 32 forest management indicators.•Arthropods, birds, and plants are the most frequently used biodiversity indicators.•14 Forest management measures ...were defined to influence biodiversity indicators.•We identified 17 umbrella species, but clear thresholds for forest management are still missing.•Measures related to deadwood, stand structure and management intensity affect biodiversity most.
The accelerating global rate of species extinctions and the inevitable human impacts on biodiversity have increased the need to conserve, restore and use ecosystems sustainably. Indicators for biodiversity are the most frequently used tool to monitor the status of biodiversity, changes to biodiversity, and the effects of management actions. In this study, we aim to assess the magnitude of studies on indicators for biodiversity (IB) in European forest ecosystems, establish and analyze the link between IB and silvicultural management measures (MM), and define indicators for management (IM), that aim to support biodiversity at the stand and landscape level. We performed a systematic literature review and analyzed data from 162 studies. We identified 9 IB groups, corresponding to 32 IB and linked them to 7 IM groups corresponding to 44 IM. Arthropods, birds, and plants are the most frequently used IB in European managed forests. We found IB with clear links to specific IM, such as saproxylic species and Collembola (collembolans) with deadwood, bird families (Passeriformes, Piciformes, Accipitriformes) with links to microhabitats, and ground-dwelling species with links to regeneration. We identified 17 species as proposed umbrella species based on the studies examined. This review shows that high structural diversity is associated with an increase in diversity, especially with regard to vascular plants, birds and ground-dwelling species. The adaptation of forest management for biodiversity requires regular active monitoring of IM to assess the temporal and spatial changes and of IB to assess the effectiveness of measures.
Invasive alien species (IAS) are one of the major threats to global and local biodiversity. In forest ecosystems, the threats caused by IAS include hybridization, transmission of diseases and species ...competition. This review sets out to analyze the impact of alien plant species on forest regeneration, which we consider to be one of the key stages in tree ecology for the survival of forest ecosystems in the future. The focus of the study is directly relevant to practitioners, forest managers and the conservation management of forests. With this systematic review, we aim to provide an overview of 48 research studies reporting on the impact and/or management of IAS in European temperate forests. We followed a multi-step protocol for compiling the publications for the literature review, with nine search queries producing a total of 3,825 hits. After several reduction rounds, we ended up with a grand total of 48 papers. We identified 53 vascular plant species having a negative influence on forest regeneration in Central European forests. In total, 21 tree species are reported to be impacted by IAS in 24 studies. The results of the review synthesis show that five impact mechanisms affect the regeneration success of native tree species: competition for resources, chemical impact on regeneration, physical impact on regeneration, structural impact on regeneration and indirect impact through interaction with other species. We identified in our synthesis management measures that have been recommended for application at different stages of biological invasions. The associated costs and required resources of management measures are under-reported or not accessible by reviewing the scientific literature. We can thus conclude that it is very import to improve the links between science and practical forest management. We expect that this review will provide direction for invasive plant species research and management aimed at protecting biodiversity in European temperate forest ecosystems.
Forestry is facing an unprecedented challenging time. Due to climate change, major tree species, which until recently fulfilled major ecosystem services, are being lost and it is often unclear if ...forest conversion with other native or non-native tree species (NNT) are able to maintain or restore the endangered ecosystem services. Using data from the Austrian Forest Inventory, we analysed the current and future (2081-2100, RCP 4.5 and RCP 8.5) productivity of forests, as well as their protective function (avalanches and rockfall). Five different species change scenarios were considered for the replacement of a tree species failing in the future. We used seven native tree species ( Picea abies, Abies alba, Pinus sylvestris, Larix decidua, Fagus sylvatica, Quercus robur and Quercus petraea ) and nine NNT ( Pseudotsuga menziesii, Abies grandis, Thuja plicata, Pinus radiata, Pinus contorta, Robinia pseudoacacia, Quercus rubra , Fraxinus pennsylvanic a and Juglans nigra ). The results show that no adaptation would lead to a loss of productivity and a decrease in tree species richness. The combined use of native and NNT is more favorable than purely using native species in terms of productivity and tree species richness. The impact of the different species change scenarios can vary greatly between the different environmental zones of Austria (Alpine south, Continental and Pannonian). The Pannonian zone would benefit from the use of NNT in terms of timber production. For the protection against avalanches or rockfall in alpine regions, NNT would not be an advantage, and it is more important if broadleaved or coniferous trees are used. Depending on whether timber production, protective function or tree species richness are considered, different tree species or species change scenarios can be recommended. Especially in protective forests, other aspects are essential compared to commercial forests. Our results provide a basis for forest owners/managers in three European environmental zones to make decisions on a sustainable selection of tree species to plant in the face of climate change.
Woody and non-woody plant species conservation is one of the ecosystem services provided by agroforestry (AF) systems across the agricultural landscapes. Little attention has been paid to assessing ...the conservation of plant diversity in AF systems. This study was, thus, aimed at investigating plant species diversity, structure, and composition of three AF systems in Gedeo zone of south-eastern rift–valley agricultural landscape of Ethiopia. The study was conducted in three agroforestry systems, namely, enset based, coffee–enset based (C–E based AF), and coffee–fruit trees–enset based (C–Ft–E based AF) agroforestry systems. Twenty farms representative of each AF system were randomly selected, and inventory of the floristic diversity was employed in a 10 m × 10 m sample plot per farm. A total of 52 perennial woody and non-woody plant species belonging to 30 families were recorded. Of all species identified, 33 (63.5%) were native, of which two species, namely Millettia ferruginea (Hochst.) Baker and Erythrina brucei Schweinf., were registered as endemic. The highest proportion of native species was recorded in enset based AF (93.3%), and the least were in C–Ft–E based AF (59%). According to the IUCN Red List and local criteria, 13 species were recorded as being of interest for conservation in all AF systems. The woody species Prunus africana was identified as both vulnerable by IUCN Red List and rare for 25% of species that least occur. The Shannon diversity index and richness showed that C–Ft–E based AF systems were significantly different from the two remaining AF systems. However, the species abundance and evenness did not show significant differences between the three AF systems. In general, retaining such numbers of woody and non-woody perennial plant species richness under the AF systems of the present study underlines their potential for biodiversity conservation.
Non‐native tree species (NNT) are used in European forestry for many purposes including their growth performance, valuable timber, and resistance to drought and pest or pathogen damage. Yet, ...cultivating NNT may pose risks to biodiversity, ecosystem functioning, and the provisioning of ecosystem services, and several NNT have been classified as invasive in Europe. Typically, such classifications are based on risk assessments, which do not adequately consider site‐specific variations in impacts of the NNT or the extent of affected areas. Here, we present a new methodological framework that facilitates both mitigating risks associated with NNT and taking advantage of their ecosystem services. The framework is based on a stratified assessment of risks posed by NNT which distinguishes between different sites and considers effectiveness of available management strategies to control negative effects. The method can be applied to NNT that already occur in a given area or those NNT that may establish in future. The framework consists of eight steps and is partly based on existing knowledge. If adequate site‐specific knowledge on NNT does not yet exist, new evidence on the risks should be obtained, for example, by collecting and analyzing monitoring data or modeling the potential distribution of NNT. However, limitations remain in the application of this method, and we propose several policy and management recommendations which are required to improve the responsible use of NNT.
A new methodological framework for site‐specific risk assessment facilitates mitigating possible negative impacts of non‐native tree species while using their ecosystem services in European forests. The method is based on a stratified assessment of risks posed by non‐native tree species that distinguishes between different ecosystem types and considers the effectiveness of available management strategies to control negative impacts. To improve the practical value of non‐native tree species risk assessments, we propose six recommendations that address forest and environmental policy as well as forest management.
Active forest management and maintenance or restoration of biodiversity are intertwined. We describe several Central European forest types through typical management cycles and identify synergies and ...trade-offs with biodiversity conservation. Synergies emerge when the maintenance of forest structures supporting recognized human needs for biomass production create diverse habitats. On the stand level, relevant are tending interventions during stand development, the length of the production cycle, and the choice of tree species. Thinning promotes forest productivity, enhances structural heterogeneity, and the habitat diversity for many species groups. The vertical and horizontal diversity on the stand level is high in uneven-aged multi-species forests. The choice of the rotation period is controversial, because no balance between forest productivity, stand stability, and habitat quality is yet negotiated. On the landscape level heterogeneity arises when many actors implement a range of silvicultural concepts and management intensities. Deadwood of different dimensions provides multiple habitats and enhances biodiversity, but causes challenges for forest protection in some forest types. A possible compromise is setting aside unmanaged interconnected units with veteran trees (stepping-stone habitats). Damage caused by wildlife is an un-resolved issue in Central European forests. High ungulate populations are reducing the potentially emerging diversity of tree species by selective browsing. A controversial topic is the introduction of non-native tree species, potentially filling in where native tree species cannot cope with expected future site conditions. Their introduction may lead into uncharted territory with respect to biotic threats. In conclusion, the knowledge-based discourse between nature conservation and forest management needs to be continued to further develop the successful concept of multiple-use forestry.
•We tested a rapid assessment for saproxylic insects based on feeding galleries and boreholes.•3641 standing and lying dead objects were examined in 1,444 NFI plots for insect traces.•We found 2,770 ...insect traces of the orders Coleoptera (n = 2,624), Hymenoptera (n = 143) and Lepidoptera (n = 3)•All insect abundances increased on trees taller than 18 m and above a living stand volume of 41 m3ha−1.•We recommend a tree species-specific dead wood management already considering living wood.
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.
The Mura-Drava-Danube transboundary UNESCO Biosphere Reserve represents one of the best-preserved wetlands in Europe. The Reserve’s riparian forests play a significant role in ecosystem functioning ...and pedunculate oak (Quercus robur) is one of the keystone species of these forests. In recent years, pedunculate oak trees in the Reserve displayed symptoms of necrotic lesions on their leaves. The lesions varied in size, from small, circular to irregular reddish brown to grayish spots to larger necrotic areas that resembled leaf anthracnose and extended along the leaf nerves. In 2021, symptomatic leaves were collected in three countries of the Reserve, i.e. Austria, Slovenia, and Serbia to identify the causative agents of these diseases. Fungal cultures were obtained from symptoms and identified using morphology and multilocus phylogenetic analyses of the ITS rDNA, partial LSU rDNA, tef 1-α, BT2, CAL, ACT, and RPB2 genes. The fungi were identified as Tubakia dryina , Tubakia sp. ( Tubakia dryinoides sensu lato ), Didymella macrostoma , and Apiognomonia errabunda . Pathogenicity tests done by inoculating the leaves of one-year old pedunculate oak plants revealed that the isolated fungi caused symptoms as those seen in the forest. To our knowledge, this study represents the first report of D. macrostoma as the cause of pedunculate oak leaf spot disease in Serbia and worldwide. It is also the first finding of Tubakia leaf spot disease of pedunculate oak caused by T. dryina in Austria and Serbia. Moreover, Tubakia sp. was proven to be another causative agent of Tubakia leaf spot disease. Additionally, oak anthracnose caused by A. errabunda was found for the first time on pedunculate oak leaves in Austria and Slovenia. During the past decade, pedunculate oak trees have been facing increasing threats from multiple abiotic and biotic factors which has resulted in decline and absence of natural regeneration of these trees. The results of this study add to the understanding of the contributing factors to the decline of pedunculate oak in riparian forests and are important for the development of management strategies to counteract this decline.
Purpose of Review
As litter decomposition is a fundamental process in forest ecosystems, representing the link between aboveground and belowground biogeochemical processes, we developed an effect ...size summarisation of the implications of forest management on litter decomposition rate, by applying a multi-level meta-analysis and multivariate mixed-effects meta-analytic linear models. Our aim was to review the findings of the current literature and to understand how forest management, silvicultural treatment, and forest operations could affect litter decomposition rate. Furthermore, we investigated the effects of environmental variables that included stand type, climatic conditions, and the percentage of biomass removal on litter decomposition rate.
Recent Findings
We found a statistically significant reduction in litter decomposition rate associated with clear-cutting, and no statistically significant differences for the overall effects of retention forestry and logging activities (disturbed forest soil in the form of skid trails or strip roads). Concerning the sub-group analysis and multivariate meta-regression, there were no significant effects for stand type (broadleaf, coniferous, or mixed) or climatic conditions (mean annual temperature and annual precipitation). The percentage of biomass removal showed a significant positive correlation with the effect size, thus indicating that higher biomass removal in the framework of retention forestry leads to an increase in litter decomposition rate. Also, the mesh size of the litterbag showed a positive correlation with the effect size, suggesting that there is a probability of a factor of stronger disturbance to large-body decomposer organisms such as microarthropods.
Summary
Litter decomposition rate is related, among other factors, to soil microclimatic conditions and soil biota. Therefore, this process can be strongly influenced by active forest management, meant as a silvicultural treatment carried out by applying a given harvesting system. In the context of retention forestry, increased light availability seems to be the driving force in shaping increased litter decomposition rates with increasing biomass removal. On the other hand, when a clear-cut is applied, the stronger modification to the edaphic community leads to decreased litter decomposition rates. It is worth noting that the modification may also be related to soil manipulation to favour the establishment of artificial regeneration. The findings, however, showed very large variability, thus suggesting the need for further research on such a complex topic. Multidisciplinary studies that analyse the microclimate and the edaphic biological communities along with the litter decomposition are particularly recommended.
Diet is important for understanding the ecology and evolution of populations. When examining animals’ diets, the lowest taxonomic rank (i.e., species level) is generally used. However, it is ...questionable whether dietary description varies with respect to the plant taxonomy or with the extent of plant species diversity in landscapes. We studied the diet of the Alpine mountain hare (
Lepus timidus varronis
) by analyzing the botanical composition of fecal pellets and comparing the results with the availability of food plants. Overall, Alpine mountain hares selected ligneous plants, whereas grasses were neutrally consumed or avoided. Plant identification at the genus and family level revealed the most information, whereas little additional information was gleaned by identifying food plants at the species level. In low-diversity spruce forests and at higher elevations, hares exhibited greater diet breadth compared to high-diversity vegetative mosaics or at lower elevations, even if they had access to the same types of plants. This is likely due to the hares’ need to diversify their diet when plant quantity is low. Greater diet breadth and selection of a larger number of different plant types at the beginning of the plant vegetation growth period suggested that more food plants suitable for Alpine mountain hares were available during this time compared to the end of the vegetation period.
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