Europe has been dominated by cultural landscape and rather intensively managed forests. It is thus no surprise that the ongoing global biodiversity crisis as well as the consequences of climate change have been apparent. In recent years, forestry in Central Europe has been going through a crisis caused by extensive disturbances primarily in commercial monocultures; this phenomenon is particularly striking in the Czech Republic. Given the significance of the situation, it is essential to review and optimise the current forest management practices in relation to biodiversity protection. Therefore, a survey among Czech biologists was conducted in an effort to provide specific feedback to foresters and other stakeholders based on scientific and empirical knowledge of the survey respondents. The survey assessed the forest habitat (in terms of light conditions and the structure of the forest environment), forest management tools and conceptual approaches regarding specific species and groups of organisms. The respondents negatively perceived the current forestry practices, especially in terms of creating homogeneity across the forest environment and eliminating important habitats. Structurally diverse old-growth forests as well as the open forests with the presence of old and habitat trees were emphasised by the survey respondents as essential environments. Large-scale non-intervention within protected areas is necessary to support the presence of old-growth forests. On the other hand, there is an urgent need to restore open forests which requires (but not exclusively) the active efforts of man. These two basic appeals are essential in order to diversify the landscape through a combination of segregative and integrative forest management tools that aim to support biodiversity.
The biodiversity of temperate forests in Central Europe has been influenced by human activities since the onset of forest formation in the postglacial era (
Important factors such as spatial and temporal continuity of forest sites have been recognised by experts and their empirical observations (
The aim of this study was to gain information regarding biologists’ opinions on the effects of forest management on forest biodiversity by means of a survey. We used this information to outline the main challenges we have been facing in the field of forest biodiversity protection in the Czech Republic. The study focuses on whether and how current forestry management threatens biodiversity; what habitats, ecosystem features and structural elements deserve the most attention; and what management forms and tools are currently most relevant to support biodiversity in the Czech Republic. Additionally, we aimed to suggest changes in the approach to forest management that would lead towards a substantial mitigation of biodiversity decline and help raise crucial questions supporting further research and discussion on this topic.
The survey was conducted in the Czech Republic where forests cover about 33% of the land (
In the survey we involved experts and professionals in biodiversity of forest ecosystems affiliated to scientific and specialised institutions focusing on ecology, biology and biodiversity protection. The expertise of the respondent in a specific field was required in order to complete the survey regarding the given biota. The survey was carried out between October 2016 and June 2017. A link to an online survey was created using the website https://www.survio.com/ and emailed to the following institutions in the Czech Republic: all university departments of natural sciences and forestry; the Czech Academy of Sciences; research institutes, professional and scientific societies; natural history museums; administration offices of all (4) Czech National Parks; and all (24) Czech protected landscape areas. The list of approached institutions is presented in the supplementary Tab. S1 (Supplementary material). The total of 64 institutions were approached and asked to forward the survey onto their members of staff. The survey website was visited 610 times (the total number of people who received the survey invitation is however unknown). A document including the definitions of the key forestry terms accompanied the survey.
We asked each respondent to complete the survey questions bearing in mind individual species or a group of organisms. The respondents were asked to complete the survey again in the case they wish to include another species or a group of species.
Although nearly a quarter of the surveys (23%) were completed for a particular genus or species, the majority was functionally or taxonomically defined group of organisms; the list of evaluated species and groups is presented in Tab. S2 (Supplementary material). The received responses were consequently sorted according to the taxonomical groups as follows: invertebrates (35), vertebrates (21), higher plants (26), fungi (7) and lichens (5). This subsequent classification eliminates any ambiguity in the cases where the respondents answered to functional groups without a nomenclature specification. One response was filled in for nature in general and could not be included in the defined taxonomic group; nevertheless, it was included in the overall summary.
The full detail of the survey is shown in the Appendix 1 (Supplementary material). First of all, the respondents were asked to evaluate whether they believe the forest management in the Czech Republic threatens, supports or remains neutral towards the species group or the taxon of their choice (question 2.3). Afterwards, they assessed the most significant, and in scientific literature widely discussed, attributes of forest management (question 2.4): the presence of non-native tree species composition, most commonly used forest management systems (
In the second part of the survey, the respondents were asked to rank various types of habitats and structural features (question 2.5) according to their light conditions, stand age, structural complexity, but also according to the degree of human influence (
The respondents further evaluated the main management tools practised in both forestry and nature conservation (
The scale of answers used in the first two survey parts (
The respondents were asked to express whether the assessed groups or taxa can be considered as an umbrella species (or group of species) for another biota in the third part of the survey. This question was open-ended to allow the respondents to specify the relation. The respondents were also requested to provide additional comments or feedback at the end of the survey.
The respondents’ answers to particular questions were sorted according to their frequency and proportion. The taxonomic groups (due to the variation in respondents’ specialisation) were unevenly represented in the total set of received answers. Therefore, the aggregated proportion of the responses for the whole set was calculated as the mean of the percentages achieved for a given response within individual taxonomic groups. All taxonomic groups were evaluated with the same weight.
Box plots were used to visualise the questions results related to forest management aspects (question 2.4) and forest management tools (question 2.6). The questions yielding a categorical range of answers,
The importance of individual qualitative characteristics of forest sites and management tools in relation to biodiversity was discussed in a continuous prose. The study focused on apparent trends based on numerical majority or rarity of the given responses.
Preliminary survey results were presented as a pilot study in
The survey was completed by 83 respondents (specifically by 46 scientists, 12 natural history museum experts, 10 members of nature conservation administration and 15 nature conservation practitioners); 78 of them completed the survey once, three respondents completed it for two separate groups, one respondent completed it for three separate groups and one for eight separate species. Some respondents provided incomplete answers and their responses were therefore excluded from the analysis. Altogether, 95 completed surveys were analysed. The estimated survey response rate was 16% (the response rate was estimated from the number of visits to the survey website since the total number of people who received the survey invitation
Ninety-four per cent of the respondents (
The biodiversity of evaluated species was reported to be endangered (in general) by the application of forest management practices in 84% of the completed surveys. However, one survey respondent (expert on birds) stated that forest management generally supports biodiversity. The respondents mentioned a neutral relationship between biodiversity and the application of forest management in 15% of the responses. The degree to which forest management endangered particular taxonomic groups varied with the highest being reported for lichens and invertebrates and the lowest for fungi (
Overall, homogeneity across forest sites due to the use of forest management was most frequently stated as having a negative impact on individual species groups by the survey respondents. This trend was apparent in the overall summary (
The respondents considered the presence of non-native tree species composition as negative in three quarters of the responses. As for the practice of particular forest management system, clear-cutting in even-aged forest stands was most frequently ranked as having a negative influence on biodiversity of stated species in 79% responses but was reported as ambivalent in 15%. The use of chemical treatments and heavy-duty machinery was evaluated by the survey respondents as having a negative influence on the species groups (81%), which was similar as in the case of post-disturbance salvage logging and deadwood removal (82%); these factors were not assessed positively by any respondents.
The utilisation of shelterwood system was graded as the most positive factor since only 27% of the responses mentioned it as having a negative influence. In addition, the shelterwood system was pronounced as having the most positive and ambivalent influence in 20% and 19% of responses, respectively. Nonetheless, 80% of the responses showed shelterwood system as having a negative impact on the group of lichens. The exclusion of natural regeneration formed by pioneer species was considered as neutral in 42% of cases. The abandonment of historical forest management types was evaluated negatively (46%), especially concerning invertebrates (77%), although it was seen as rather neutral (29%) or ambivalent (43%) for fungi and completely neutral (100%) for lichens. The respondents’ answers are shown in full in Fig. S1 (Supplemetary material).
Data processing using boxplots visualised (in an alternative way) the negative evaluation of most commonly used forest management aspects (
Old-growth forest was stated as the key habitat in almost three quarters of the responses (
Diverse forest stand structure and diversity in general were considered as the key factors in 56% of the responses. These were followed by the large unmanaged reserves (54%), the long-term retention of entire forest stands (52%) and the presence of near-natural tree species composition (51%). In the case of higher plants, the respondents observed an importance in reduction of stand density (evaluated as key in 54%). The clear-cutting system and the maintenance of the current tree species composition were seen as negative in 70% and 38%, respectively. In the case of biodiversity protection, clear-cutting system was not evaluated as key by any respondent and was marked as suitable only in five cases. Uneven-aged forest management and the use of selection systems were most frequently (66%) marked as suitable and as key in 9% of the responses. Although the influence of historical forest management types (
The clear-cutting system and the current tree species composition were shown to have been negatively evaluated (see Fig. S3 in Supplementary material). Coppicing and forest grazing were perceived as having a neutral effect. On the contrary, close to nature tree species composition, large non-intervention reserves, retaining micro-reserves and small-scale disturbances within the forests, long-term retention of entire forest stands, the efforts to achieve spatial diversity and connectivity of habitats were evaluated above the mean. The evaluation of individual taxonomic groups was balanced with a slightly higher urgency for changes in the management of lichens (see Fig. S4 in Supplementary material).
Most of the responses (73%) showed the combination of segregation and integration approach to be the most important in terms of forest biodiversity protection. The importance of integration and segregation separately reached 19% and 9% of the responses, respectively. Minimal intervention (53%) was favoured (on average) over active forest management approaches (47%) considering the conceptual forest management approaches. The minimal intervention was strongly preferred for lichens and fungi in 80% and 86% of the responses, respectively (
Three quarters of the responses found the assessed species or species groups to be umbrella species. The proportion varied among individual groups: higher plants (65%), fungi (71%), invertebrates (77%), lichens (80%) and vertebrates (81%).
The survey results pointed out towards numerous detrimental effects of current management practices on forest biodiversity. Such survey has not been published for the Central European area, however, its focus is closest to the study conducted for northern European boreal forests by
Forest management is mostly represented by logging that has a negative influence on biodiversity, which has been well-documented, but often difficult to prove in a short-term perspective, especially in the case of less extensive management types such as the selection and shelterwood systems (
Although the pioneer species significantly contribute to forest biodiversity (
The survey results show the importance of two habitats,
As far as the old-growth forests are concerned, it is known that the areas of several or tens of hectares in Central Europe, which are common sizes of current forest reserves, are insufficient for an adequate functioning of their dynamics (
The negative impact of simply-structured commercial monocultures on biodiversity is apparent. Commercial monocultures (primarily in a sense of plantations) replacing more complex forests have to be distinguished from natural species-poor and other specific native ecosystems which was also noted by the survey respondents. In other words, native broadleaved stands (
The presence of key structures such as deadwood is essential for the forest biodiversity (
The forest of seed origin was given priority over other stand types (
The results indicated that it is important for biodiversity protection to achieve a rich mosaic of connected habitats within the landscape and to support the native tree species composition in the managed forests. The landscape mosaic, according to the survey respondents should contain elements of large unmanaged reserves where whole stands or their parts are retained in a long-term and where the application of active management also aims at restoration and preservation of the open forests,
Other management tools (forest grazing, coppicing, removing introduced tree species, high stumps creation, etc.) were evaluated as suitable. These tools were stated as being ambivalent, insufficiently researched, unsuitable or harmful. Such answers can be explained by the respondents’ emphases on the need of mosaic and diversity all the way up to the landscape scale. That is why the active management tools should be combined. The application of a single management tool could lead to a large-scale forest homogenisation with an insufficient presence of necessary habitats. This also includes the selection system (
The benefits and novelty of this study can be further recognised in the context of recent natural disturbances of commercial forests in Europe caused primarily by climatic effects, the spread of bark beetles and the effects of previous forest management (
Natural disturbances are widely recognised as a key factor for forest biodiversity (
Such notion was supported by our study where the survey respondents positively evaluated the abandonment of salvage logging after both small- and large-scale natural disturbances. The post-disturbance presence of biological legacies in forest stands provides an opportunity (at least temporary) for the creation of an open forest and for natural regeneration; however, vast clear-cuts were created instead in numerous places.
This study’s results confirmed the necessity to combine segregative and integrative tools in order to protect species in the hotspots of their presence as well as within the landscape matrix (
These efforts may be concerning due to the loss of viable production. The need for research into the effects of various forest management approaches (including conservation practices) on ecology and the economy stems from an expert survey conducted in Hungary (
Minimal intervention with nature protection in mind is commonly considered to be a basic (or the best) form of forest ecosystem management (
The fact that most respondents whose expertise is on invertebrates and higher plants preferred an active management can be explained by an urgent need of open forests recovery. The efforts to replace or restore the presence of large herbivores, wildfires or historical management types requires an active management approach, especially in lowlands. Forest management should consider the millennia-lasting human activities.
It has to be mentioned that some respondents found the general choice between minimal intervention and active management very difficult. For example, one respondent assessing saproxylic beetles of higher altitudes confirmed the minimal intervention preference but pointed out that forest grazing supports biodiversity in the Alps. The preferences for non-intervention and active management were, on average, very balanced. The question where and in which situation shall be the biodiversity supported by either minimal intervention or active management is considered as essential for further research and for the discussions regarding the effects of forest management practices on biodiversity.
A substantial part of specific biota or even whole habitats can be effectively protected by focusing on umbrella species. Studies related to these species are often applied (
The adverse impact of commercial forestry on biodiversity is rather difficult to be unambiguously researched mainly due to the delayed results in science. However, many of these influences can be suitably identified on the basis of personal experience of experts and professionals. The research focused on empirical knowledge of biologists supported both by their research findings and their overall view. Although such data are inherently subjective, they allow revealing potentially significant factors influencing biodiversity that have not been sufficiently focused on so far.
Survey-based studies appear to be a suitable tool to fill the gaps between research and practice (
Since the study is based on the knowledge on endangered species and groups of organisms, the respondents are primarily biologists or experts in biodiversity but not necessarily foresters. This may be limiting since the respondents may not be fully familiar with details of forest management practices and terminology. However, we tried to overcome such constraints by including the explanation of basic forestry terms in the survey. We believe that experts on forest biota are well able to assess the effects of the environment and management on the given biota even without detailed knowledge of forest management practices and terminology.
Another shortcoming of the study may be the subjective interpretation of some assessed categories such as “primary or unmanaged forest” or “mature stands”. Potential differences, similarities, overlaps and contexts of the assessed categories could affect the respondents’ understanding and answers. However, every effort was made to use self-explanatory terms that have long been established in the scientific and professional literature when creating the survey.
The restraints arising from a limited number of responses have to be taken into an account when assessing the results especially in relation to particular groups of organisms. On the other hand, all the responses related to the groups with the lowest frequencies (fungi and lichens) comprised of a wide range of these groups. Uneven response frequencies and respondents’ freedom in filling in made the statistical comparison between individual groups impossible. Such study approach can, to a certain extent, help stakeholders deal with biodiversity crisis in Central European forests and make decisions that can translate into practice.
The conventional forest management practices used in many countries create conditions that lead to the risk of local extinction of a range of species. Therefore, it is necessary to revise current forestry approaches since the recent improvements have not been sufficient. This finding should be a starting point for dealing with forest biodiversity crisis. Complex forest structure and habitat connectivity were considered by the survey respondents as a key factor to support biodiversity in contrast to uniform commercial forest (mostly monocultures) of simple stand structure. Changes in tree species composition and logging forms are important. The structural diversity of European commercial forests is rather low,
All the above-mentioned findings are applicable to the current Central European forestry crisis. The uniform commercial forests in Central Europe have been increasingly affected by severe natural disturbances which offer an opportunity for developing structurally more complex forests. Therefore, partial retention of certain biological legacies (
This research has been supported by funding from the Czech University of Life Sciences Prague (EVA 4.0 project: CZ.02.1. 01/0.0/0.0/16_019/0000803).
The conglomerated visualisation of three evaluated general questions: (i) the rate of threat to biodiversity generated by forest management (scale: supported, neutral relation, threatened); (ii) the choice among conceptual biodiversity protection approaches (integrative tools, segregative tools, their combination); and (iii) the choice between managed and unmanaged forests maintaining biodiversity protection. The total numbers of responses vary among taxonomic groups. The group “all” shows the mean values of the proportions for the answers obtained within individual taxonomic groups.
Boxplots showing the markings of forest management factors by the survey respondents. The marks (
Evaluation of different habitat types in terms of their importance for particular biota (scale: key, usable, insufficiently known relation, unusable). The complete set of all responses as well as the responses for individual taxonomic groups are presented. The total numbers of responses vary among taxonomic groups. The group “all” shows the mean values of the proportions for the answers obtained within individual taxonomic groups.
The evaluation of different types of management measures in terms of their influence on biota (scale: key, suitable, ambivalent, insufficiently known relation, unsuitable, harmful). The complete set of all responses as well as the responses for individual taxonomic groups are presented. The total numbers of responses vary among taxonomic groups. The group “all” shows the mean values of the proportions for the answers obtained within individual taxonomic groups.
Appendix 1 - An example of a survey released to the respondents.
Appendix 2 - A short description of the management tools.
Fig. S1 - Frequency of responses evaluating particular factors of forest management in terms of their influence on species.
Fig. S2 - Boxplots showing the markings of forest management factors by the survey respondents according to individual taxonomic groups.
Fig. S3 - Boxplots showing the markings of forest management factors by the survey respondents.
Fig. S4 - Boxplots showing the markings of forest management factors by the survey respondents according to individual taxonomic groups.
Tab. S1 - The list of contacted institutions where the survey was distributed.
Tab. S2 - The list of evaluated species and species groups.