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The Bohemian Forest spans the borders of Bavaria, Czechia and Upper Austria, and is important for studying forest biodiversity in central European mountain ecosystems. This study focuses on assessing the patterns in biodiversity in the Šumava National Park. Species richness, Shannon diversity index, evenness and dominance were determined for 117 forest plots (large sample) and a subsample of 49 plots (small sample) using comprehensive monitoring techniques within the Silva Gabreta project, a cross-border initiative implemented together with the Bavarian Forest National Park. Data were collected for the following taxonomic groups: plants, fungi, mammals and invertebrates, using a variety of trapping methods and survey techniques. Results indicate significant differences in the number of species in the different taxonomic groups, with Lepidoptera, fungi and Bryophyta with the highest species richness and diversity, whereas groups such as Neuroptera, Curculionidae and mammals had lower values. Although most biodiversity indicators were not significantly different between the large and the small sample at the taxonomic level, species richness and Shannon diversity were higher in the small sample. This may be attributed to the trapping methods used in those plots, which are likely to have resulted in more complete captures of the species than in the plots of the large sample. The findings indicate that 49 plots are a suitable number for long-term biodiversity monitoring, provided key plots with efficient trapping setups are included. This study highlights the importance of careful plot selection and suggests that a mixed monitoring strategy, incorporating both broad taxonomic assessments and targeted approaches for specific taxa, may be the most effective for monitoring biodiversity.

Abstract Changes in climate and land use are the most often mentioned factors responsible for the current decline in species diversity. To reduce the effect of these factors, we need reliable predictions of future species distributions. This is usually done by utilizing species distribution models (SDMs) based on expected climate. Here we explore the accuracy of such projections: we use orchid (Orchidaceae) recordings and environmental (mainly climatic) data from the years 1901–1950 in SDMs to predict maps of potential species distributions in 1980–2014. This should enable us to compare the predictions of species distributions in 1980–2014, based on records of species distribution in the years 1901–1950, with real data in the 1980–2014 period. We found that the predictions of the SDMs often differ from reality in this experiment. The results clearly indicate that SDM predictions of future species distributions as a reaction to climate change must be treated with caution.

Species are disappearing worldwide, and it is likely that the rate of their disappearance will increase. The most important factors responsible for this are assumed to be changes in climate and land use. To determine the probability of extinction of a given species, it must be viewed as a metapopulation composed of many populations. In plants, seeds are spread by wind or water (passive dispersers), unlike active dispersers, which can actively look for a suitable site of their species. Thus, while active dispersers can locate a suitable site, passive dispersers often fail to arrive at a suitable site. The following question arises: is it better for the survival of a metapopulation of passive dispersers to concentrate on conserving a few large populations, each of which will produce many propagules, or on many small populations, each of which will produce only few propagules? Here, we address the question of which of these strategies will maximize the likelihood of the survival of such a metapopulation, using orchids as a model. We concluded that small populations should be preferentially preserved. Small populations are more numerous and more likely to occur more widely in the region studied and therefore a larger proportion of the seeds they produce is more likely to land in suitable habitats than that produced by the fewer large populations. For conservation, there is a possibility to extend the results to other taxa. However, this must be carried out with caution and must consider the taxon in question.

Questions concerning species diversity have attracted ecologists and biogeographers for over a century, mainly because the diversity of life on Earth is in rapid decline, which is expected to continue in the future. One of the most important current database on species distribution data is the Global Biodiversity Information Facility (GBIF), which contains more than 2 billion occurrences for all organisms, and this number is continuously increasing with the addition of new data and by combining with other applications. Such data also exist in several national databases, most of which are unfortunately often not freely available and not included in GBIF. We suspected that the national databases, mostly professionally maintained by governmental organisations, may be more comprehensive than GBIF, which is not centrally organised and therefore the national databases may give more accurate predictions than GBIF. To test our assumptions, we have compared: (i) the amount of data included in the Czech database called Nálezová databáze ochrany přírody (NDOP, Discovery database of nature protection) with the amount of data in GBIF after its restriction to the Czech Republic, and (ii) the overlap of the predictions of species distributions for the Czech Republic, based on these two databases. We have used the family Orchidaceae as a model group. We found that: (i) there is a significantly larger number of records per studied region (Czech Republic) in NDOP, compared with GBIF, and (ii) the predictions of Maxent based on orchid records in NDOP are overlapping to a great degree with the predictions based on data based on orchid records in GBIF. Bearing in mind these results, we suggest that if only one database is available for the region studied, we must use this one. If more databases are available for the region studied, we should use the database containing most locations (usually some of the local ones, like NDOP), because using more locations implies larger significance of predictions of species distributions.

Orchids can be classified in terms of their pollination into rewarding species, which produce nectar in their flowers that serves as a reward for pollinators and deceptive species, whose flowers do not contain nectar and save energy for other purposes. This paper concentrates on the latter. Deceptive orchids attempt to deceive their pollinators by being similar to some non-orchid rewarding species, but not providing a reward. Each of these strategies has its advantages and disadvantages in terms of their effect on future fitness of a plant and/or population and subsequently its survival as a species. In summary, the literature indicates that deceptive strategies may lower reproductive success, but may be compensated for in that they cost less in terms of energy. This should be taken into consideration when developing management strategies for these species, which is often done by non-orchid specialists. This article is intended for such non-specialist audience and includes a description of the main types of deceptive strategies used by orchids, as well as examples of the most typical species.

When examining the probability of extinction of a given orchid species, the species must be viewed as a metapopulation composed of many individual populations connected by migration. In biology, much attention has been paid to the dynamics of metapopulations, especially in the situation where metapopulation dynamics are affected by active migration of individuals between populations. However, this is not the case with orchids. Their seeds are passively spread by wind, and therefore are unable to actively choose the point where they land (passive migrants, unlike, e.g., butterflies, which can actively look for a suitable site that hosts, hosted or can potentially host a population of their species (active migrants). Thus, while active migrants can often find a suitable destination for their migration, passive migrants often die after landing at an unsuitable site. One would therefore expect that, other things being equal, the proportion of suitable sites inhabited by active migrants is larger than that inhabited by passive migrants. In passive migrants (orchids) we may therefore meet metapopulation dynamics of a different, yet unexplored type, in which some existing localities die out and new localities appear, in the vast majority where no orchids have ever grown before. This type of dynamics has not yet been studied anywhere and this paper is intended to be the first step in this direction. The main goal here is therefore empirical determination of actual distributions of population sizes in different metapopulations. We do it in four regions of the Czech Republic and for four species of orchids, considering the factors that influence it.

Population dynamics of a predator-prey system is usually simulated by the classical Lotka-Volterra models, which were successfully applied to the population dynamics of snowshoe hare and lynx and many other predator-prey systems. Attempts were made to apply them also to insect predator-prey systems, but in terms of biological control, they did not reveal the features of the predators that control the abundance of their prey. The most conspicuous example of failure of Lotka-Volterra models applied to insect predator-prey systems are ladybird-aphid systems, in which these models usually fail to fit empirical data. Because of their practical importance and because they are very well studied, we have chosen aphid-ladybird systems as a model. We summarize the results published on various aspects of the population dynamics of aphid-ladybird systems and present them in the context of empirical data. Using new data, we more closely specify the existing metapopulation model of aphid-ladybird interactions. Based on the arguments presented here, we conclude that the ladybird-aphid case can be generalized to insect (and maybe even other) predator-prey systems, where the ratio of the generation times of the predator to that of the prey (GTR) is large. In such systems, the main selection pressure on predators is choosing the best strategy to maximize survival of their offspring, rather than on maximization of the amount of prey eaten. Thus voracity, which is the main determinant of population dynamics in Lotka-Volterra models, loses its role and is replaced by optimization of the choice of oviposition sites in systems with large GTRs.

The natural environment has been significantly altered by human activity over the past few decades. There is evidence we are now experiencing the sixth mass extinction, as many species of plants and animals are declining in abundance. We focused on the Orchidaceae because this plant family has experienced one of the biggest reductions in distribution. We investigated patterns in species richness and distribution of orchids, the rate and causes of their decrease and extinction, and factors influencing their occurrence in the Czech Republic and Greece. The key findings are: (i) Method of pollination and type of rooting system are associated with their distributions and they are different in the two countries. We assume that these differences might be due to the difference in the orography, distribution of suitable habitats and types of bedrock in these two countries. (ii) The greatest reduction in distribution was recorded for critically endangered taxa of orchids. The number of sites suitable for orchids in the Czech Republic declined by 8–92%. The most threatened orchid species are Spiranthes spiralis, Anacamptis palustris, Epipogium aphyllum and Goodyera repens. The distribution of orchids in the Czech Republic is mainly determined by the distribution of their habitats. (iii) The most important factor affecting the distribution of Czech orchids in South Bohemia is land cover. And the most important types of habitats (types in KVES) are oak and oak-hornbeam forests and agricultural meadows. Based on this information, it should be possible to improve the management that is crucial for maintaining orchid localities.

By monitoring of 50 aphid colonies in 2017 and another 50 colonies in 2018 twice a week, we looked at how the aphid dynamics wasaffected by their natural enemies. This will help us to see, how much the presence of natural enemies shortens the duration of an aphidcolony, which may be one of the causes, why Harmonia axyridis is not very successful in the Mediterranean: the aphid colony may exist for aperiod of time too short in the Mediterranean conditions to enable successful development of H. axyridis.

One of the key goals of conservation biology is to determine what causes declines in biodiversity and suggest ways of stopping or slowing them down. Studies on the temporal changes in the distributions of species provide critical information on temporal trends in local extinctions and information on what causes these changes. This is especially true for endangered groups of plants, such as orchids. Here we analysed changes in the distributions of orchids in the Czech Republic over three time periods when the agricultural practices differed. Orchids were divided into two groups based on whether they provide nectar to their pollinators. Moreover, we determined the effect of three different spatial resolutions on the interpretation of the results. Many species in the Czech orchid flora have become rarer over time and four became extinct. These changes are directly associated with changes in the agricultural practices in the Czech Republic that started in the 1950s, which especially resulted in the abandonment of traditional management. Mosaics of small fields were converted into huge fields and the application of artificial fertilizers increased dramatically, both of which resulted in loss of natural habitats and decline in many species of orchids - both nectariferous and nectarless species. Our results are important for conservation and are aimed at preventing further decline in orchid sites and recovery of orchid populations.

Species distribution models are a useful tool and are now often used in many branches of biology, especially when dealing with threatened organisms. In combination with GIS techniques, these models are especially important and valuable for predicting the occurrence of rare species, for example orchids. Orchids are an endangered plant group, protected worldwide. Questions about their conservation are therefore highly discussed, but not all factors affecting their survival and distribution are known. Here we present an example of using SDMs for analysing orchid species occurrence data from the Jeseniky Mountains in the Czech Republic. Our data were analysed using the MaxEnt program, which produces species distribution maps and thus allows the prediction of the potential occurrence of orchids at yet unknown localities. This program also determines the environmental factors affecting species distribution. This is important for the better protection of orchids, because only by knowing these factors can new localities be found or the management plans that are crucial for maintaining orchid localities be improved. We studied the most abundant orchid species in the given region. We determined the most important factors affecting their occurrence and also areas, where new sites are most likely to be discovered and depicted them in potential distribution maps. This approach can help in finding new localities of orchids and in understanding, which environmental factors influence the occurrence of endangered orchids.

Understanding diversity patterns along altitudinal gradients and the effect of global change on abundance, distribution patterns and species survival are of the most discussed topics in biodiversity research. Here, we determined the associations of orchid species richness and the degree of their specialization to specific environmental conditions (expressed by species specialization index) with altitude in six floristic areas in the Czech Republic. We distinguished three basic trends in these relationships: linear, parabolic and cubic. We then determined whether these trends differ between three orchid groups classified by their rooting systems: rhizomatous, intermediate and tuberous. We used distributional data on 69 species and subspecies of terrestrial orchids recorded in the Czech Republic and interpolated them at 100-m intervals along an altitudinal gradient in each floristic area. The trends in both species richness and mean species specialization index differed between the six floristic areas within each of the three orchid groups studied. These patterns are probably strongly influenced by the orography of the country and the distribution of different habitats in the six floristic areas in the Czech Republic. We also found that the most widely distributed orchid group in the Czech Republic are the rhizomatous orchids, followed by intermediate and tuberous ones.

Understanding temporal changes in the distribution and abundance of various species is one of the key goals of conservation biology. During recent decades, the abundance and distribution of many species of plants and animals have declined dramatically, mainly because of habitat loss and fragmentation. The purpose of this study is to analyze the rate of extinction of orchids at various sites in different 20-year time intervals over the last 150 years, determined according to changes in society. Using the dataset of the orchid records of the Nature Conservation Agency of the Czech Republic, we determined the disappearance rate of orchids from sites using a grid of 1 × 1 km. We found that the vast majority of orchids disappeared from many of their historical localities in all time intervals analyzed. The number of sites suitable for Czech orchids declined by 8–92%, depending on the species. The most threatened orchid species in the Czech Republic are Spiranthes spiralis, Anacamptis palustris, Epipogium aphyllum and Goodyera repens. This all seems to be closely related with changes in agricultural practices in the open as well as in forest habitats. Preserving suitable orchid habitats seems to be the key for keeping Czech orchid flora alive.

Decline in wet grasslands, which in the past resulted particularly from the intensification of agriculture, was accompanied by the loss of a lot of populations of organisms, including protected and endangered species of plants and animals associated with these habitats e.g. terrestrial orchids. The survival of populations of many species of European orchids is strongly dependent on appropriate site management, especially regular mowing or grazing. In addition, humans can negatively affect the persistence of orchid populations in various ways, such as conversion of orchid meadows into building areas, dams, roads etc. or the intensive use of fertilizers and contamination of areas by fertilisers from nearby fields. Comparison of historical data with the present distribution of orchids can reveal a lot about the main reasons for the decline in this endangered group of plants. Here we present an extensive study of the persistence of 192 historical orchid sites in South Bohemia, with particular reference to the 5 commonest species of orchids, Anacamptis morio, Dactylorhiza majalis, Epipactis helleborine, Epipactis palustris and Platanthera bifolia. We show that the most abundant species at the sites studied was Dactylorhiza majalis. E. palustris, A. morio and P. bifolia are currently not present at any of the historical localities for these species. Considering more recent history, the situation regarding orchid localities in South Bohemia is not critical, but the fate of these species should be closely monitored. The majority of this loss is due to the cessation of mowing of the sites. Thus more attention should be paid to the management of the existing sites. During this study, some new sites were discovered.