Topographic complexity supports the maintenance of a high diversity of microhabitats, which may act as important 'safe havens' - or microrefugia - for biodiversity. Microrefugia are sites with specific environmental conditions that facilitate the persistence of species during environmental changes and exhibit unique ecoevolutionary dynamics. However, our knowledge about how topographic complexity and related ecoevolutionary selective forces influence the functional and phylogenetic signatures of species assemblages in microrefugia is very limited. Although the conceptual framework on the systematic integration of plant functional traits into the study of refugia is well established, more empirical studies on functional trait composition and functional diversity in refugia are urgently needed for more effective conservation. Here we analyzed the distribution of various plant functional traits and phylogenetic patterns in microhabitats (south- and north-facing slopes, and bottoms) of 30 large topographic depressions (i.e. doline microrefugia) and microhabitats of the surrounding plateaus in two distant forested karst regions. We found that plant assemblages in the understory of dolines and their surroundings are characterized by unique functional values and combinations of traits. Doline bottoms had the highest functional diversity among doline microhabitats and supported plant assemblages with considerably different trait compositions from the plateaus. Bottoms also had the highest phylogenetic diversity. These results suggest that topographic complexity in forested dolines has a significant effect on the distribution of plant functional traits in the understory. High functional and phylogenetic diversity in doline bottoms can have important consequences for the long-term survival of plant populations, highlighting that these microhabitats may provide a higher resilience and support an adaptive community-level response to natural and anthropogenic stressors. Understanding mechanisms that drive the survival of species within microrefugia is required to determine the best conservation and management strategies.

Solar energy is the most rapidly growing renewable globally. However, ground-mounted solar panels have a high land requirement, leading to extensive, low-nature-value photovoltaic parks. This may be alleviated by considering ecological aspects during their planning, construction and mainetnance. The resulting ecovoltaic park can bring various benefits for the owners if ecosystem services related to the imporved ecological conditions are recognized and wisely utilized. A major step in developing ecovoltaic parks is the creation of a short but species-rich grassland ecosystem. There is little empirical evidence on how to achieve this; therefore, we set up an experimental sowing experiment in three formerly conventional photovoltaic parks located in the forest-steppe zone of Hungary. From the regional native grassland species pool, we selected short but competitive ones (two graminoids and 50 forbs that are often visited by pollinators), and sowed them in half of the parks (between panel rows) in October, 2022, while the other half was left as control. In 2023, we surveyed the vegetation of the sown and control parts of the parks and adjacent old-growth grasslands (as references), and found that total plant species richness and the species richness of grassland specialists increased compared to the control sites, but remained below the references. In contrast, the cumulative cover of grassland specialist species in the sown sites could reach the references. We also surveyed pollinator assemblages (hoverflies and wild bees), and found higher species richness and Shannon diversity in the sown parts then in the reference grasslands, while control parts of the parks showed intermediate values. This might have been caused by spillover from the sown parts, although flying pollinators might have also taken advantage of the permanent windshade among the panel rows of control parts, despite the low food supply compared to the reference grasslands. Our findings suggest a rapid improvement of plant and pollinator assemblages after sowing native seed mixtures in solar parks. The resulting high-nature-value grassland ecosystem can have many co-benefits for the owners, as (i) it requires lower management intensity due to the short vegetation, (ii) has the potential to offer high-quality forage for livestock or honey-bees, and (iii) lowers the widespread “not-in-my-backyard” syndrome of local inhabitants due to its attractive, flower-rich appearance.

The COVID-19 pandemic has led to a surge in plastic waste due to the widespread use of disposable protective gloves (DPGs), which pose a novel risk to the environment and potentially disrupt ecosystems. This study investigated the impact of latex and nitrile DPG fragments on the early growth and development of Brassica napus seedlings and soil microbial activity-an area not previously explored. Short-term in vitro experiments, which were performed under controlled conditions, revealed statistically significant inhibition of primary root length, with latex fragments at a 0.5% concentration reducing growth by up to 30%. To determine whether the surrounding environment of the plastic fragments and roots modulates the effects of DPGs, we also employed rhizotron systems that simulate realistic soil conditions. These systems, highlighting the role of the environment in plant responses, showed that while the effects on root and shoot growth were moderate compared with those in the in vitro setup, significant changes still occurred. The study revealed that latex fragments generally promoted leaf area, whereas nitrile fragments had mixed effects. Additionally, DPG contamination differentially altered soil enzyme activities and microbial biomass, indicating potential shifts in soil health. These findings provide compelling evidence of the complex interactions between DPGs and plant-soil systems, underscoring the ecological risks associated with this type of pollution and the urgent need for improved plastic waste management to protect agricultural ecosystems. Statement of environmental implications The presence of disposable plastic glove (DPG) fragments in agricultural environments poses a significant environmental concern, potentially disrupting root growth dynamics, altering shoot morphology, and impacting soil microbial activity. These findings highlight the need for enhanced waste management strategies to mitigate plastic pollution in agricultural settings, safeguarding plant health, soil fertility, and ecosystem resilience.

Common milkweed (Asclepias syriaca L.) is a widespread invasive alien forb in dry sandy habitats of Central Europe. It adversely affects native plant and animal communities, but its ecosystem-level effects, particularly on hydrology, are little known. Since milkweed has an extensive, deep root system and large, broad leaves, we assumed a negative effect on the soil moisture content of the hosting ecosystem. Following the before-after control-impact protocol, we first compared the soil moisture content of the top 120 cm of the soil under seven milkweed stands to that of non-invaded reference sites. We then treated half of the stands by mechanically removing all aboveground milkweed biomass and repeated the comparative soil moisture measurements. We found that milkweed stands had significantly drier soils than reference grasslands during the growing season, but the soil under milkweed stands recharged to the level of the references in autumn and winter. However, the amount of moisture needed for this recharge was lost from deeper percolation to groundwater. Milkweed treatment prevented the depletion of moisture during the growing season, saving 21.6 l m−2 of water on average. Treatment did not affect non-milkweed plant biomass, thus, moisture patterns could fully be attributed to the milkweed stands. Our results reinforce the importance of milkweed suppression in invaded grasslands, as, besides enabling the recovery of the native grassland ecosystem, it promotes groundwater recharge, which is particularly important in the dry regions of Central Europe, currently facing severe aridification due to climate change and unfavourable land use trends.

Semi-natural farming systems with high conservation value offer a valuable opportunity to meet biodiversity conservation goals without compromising agricultural production. The high conservation value of such systems often roots in their increased local or landscape-level heterogeneity, which facilitates the coexistence of different species on a small spatial scale. Gaining a comprehensive understanding of the coexistence mechanisms operating in such systems is essential to mark future conservation trajectories. To facilitate this process, in this study, we aimed to uncover the interactive effects of spatial and temporal heterogeneity on community structuring mechanisms in wood-pastures, Europe’s widespread and heterogeneous semi-natural land-use form. Using ants as bioindicators, we connected species occurrence data with fine-scale measurements of local microclimatic conditions and quantified the seasonal niche breadths and overlaps of ant species forming communities in the four different habitat types (grasslands, solitary trees, forests, and forest edges) of three Central European wood-pastures. The niche quantification (performed for 28 ant species in total) was based on four-dimensional hypervolumes, with solar irradiation, air and soil temperature, and air humidity values of every species occurrence. Our results show that despite being located close to one another, the ant communities of the four different habitat types exhibited distinct patterns of seasonal realized niche dynamics, leading to community-wide temporal changes in niche hypervolumes and hypervolume overlaps (i.e., realized niche breadths and niche overlaps). The hypervolumes of dominant ants (characterized by high behavioral and ecological dominance) were mainly determined by the favorability of environmental conditions throughout the year, and in turn, their values shaped the realized niche breadths and overlap patterns of the intermediate and subordinate species. Importantly, the niche expansions and retractions of the dominant group changed the competitive pressure within the communities (quantified by hypervolume overlaps), opening up empty ecological niches to intermediate and subordinate species during periods characterized by suboptimal environmental conditions. Moreover, the niche dynamics showed a varying pattern across the different habitat types, implying that habitat structure and the associated environmental conditions interact with the effects of seasonality even on a small spatial scale. Our results uncover the interactive effects of spatial and temporal heterogeneity on coexistence mechanisms within wood-pastures. Given the distinct patterns in community dynamics and different community structuring mechanisms of the individual habitat types, wood-pastures and other complex landscapes have the potential to sustain different communities on a small spatial scale and thus boost landscape-level biodiversity.

Topographic depressions in karst areas (dolines) play an outstanding role in maintaining small-scale environmental heterogeneity in homogeneous landscapes. Such depressions can serve as microrefugia for cool-adapted species, providing cooler and more humid conditions than the surrounding matrix (plateaus). Recent studies showed that dolines can maintain species with different functional traits compared with the surrounding areas, providing a more heterogeneous and competitive environment. However, we have limited knowledge pertaining to how microrefugia shape the functional traits of a single species. Here, we compared the functional traits of the Palaearctic ant species Myrmica ruginodis between microhabitats of dolines and the surrounding plateaus in a karst landscape. We found that the number of virgin queens was higher on the plateaus, while males were more numerous in dolines, but there was no significant difference in colony size between the two microhabitats. Dolines hosted more worker brood, suggesting potential for larger colonies. Interestingly, the repeatability of worker aggressiveness was higher and worker size was more variable in dolines, emphasizing the individual aspects of doline colonies. Our results highlight that dolines not only support species whose functional traits vary from those occurring on the surrounding plateaus, but these microhabitats also exert a filter effect on the functional traits of a given species, enriching our understanding of biodiversity maintenance. It seems that - although the biotic and abiotic conditions provided by these microrefugia are more favorable for M. ruginodis than the surrounding plateaus - the plasticity of their functional traits allows them to compensate and survive even in sub-optimal environmental conditions. This plasticity may prove to be a useful prospect in the light of the ongoing climate change.

Scattered trees in wood-pastures represent outstanding conservation value by providing microhabitats for a variety of organisms. They also diversify ecosystem services by creating shade for livestock, and capturing and storing carbon. However, trees in wood-pastures are declining Europe-wide and an appropriate legal environment to maintain them is mostly lacking. Here we looked beyond the well-documented beneficial effects of trees and assessed potential ecosystem disservices, which may drive the controversial appreciation of trees. In a grazing exclusion experiment, we assessed the effect of trees on herbage production in wood-pastures from semi-arid continental to humid montane areas in the temperate deciduous forest ecoregion, and found that trees have a suppressive effect throughout the year, although herbage nutritive value, as indicated by herbage nitrogen content, seems to be improved in spring. When we up-scaled the local ecosystem disservice on herbage yield to entire wood-pastures, the loss remained below 3%, which is lower than reported gains in livestock production due to free access to shade. Thus, the motivation for the under-appreciation of trees by land managers and decision makers may lie in that trees suppress herbage production, but the importance of this effects is offset by the magnitude of the beneficial services of trees. We recommend current wood-pasture stakeholders to revisit their attitude towards scattered trees and encourage tree planting campaigns and tree-based climate mitigation strategies to consider the protection of trees in wood-pastures and the establishment of young ones in currently open pastures up to traditionally low tree cover proportions, as livestock production is unlikely to be compromised by this action.

Invasive tree species are a significant threat to native flora. They modify the environment with their allelopathic substances and inhibit the growth of native species by shading, thus reducing diversity. The most effective way to control invasive plants is to prevent their spread which requires identifying the environmental parameters promoting it. Since there are several types of invasive plant databases available, determining which database type is the most relevant for investigating the occurrence of alien plants is of great importance. In this study, we compared the efficiency and reliability of point-based (EUROSTAT Land Use and Coverage Area Frame Survey (LUCAS)) and polygon-based (National Forestry Database (NFD)) databases using geostatistical methods in ArcGIS software. We also investigated the occurrence of three invasive tree species (Ailanthus altissima, Elaeagnus angustifolia, and Robinia pseudoacacia) and their relationships with soil, hydrological, and climatic parameters such as soil organic matter content, pH, calcium carbonate content, rooting depth, water-holding capacity, distance from the nearest surface water, groundwater depth, mean annual temperature, and mean annual precipitation with generalized linear models in R-studio software. Our results show that the invasion levels of the tree species under study are generally over-represented in the LUCAS point-based vegetation maps, and the point-based database requires a dataset with a larger number of samples to be reliable. Regarding the polygon-based database, we found that the occurrence of the invasive species is generally related to the investigated soil and hydrological and climatic factors.

Local biodiversity hotspots are often located within regions where extreme and variable environmental - e.g., climatic and soil - conditions occur. These areas are conservation priorities. Although environmental heterogeneity is recognised as an important determinant of biodiversity, studies focusing on the effects of multiple environmental het-erogeneity components in the same ecosystem are scarce. Here we investigate how topography and related microcli-matic variables and soil properties may influence the biodiversity and conservation value of karst landscapes. Karst landscapes of the world contain millions of dolines (i.e. bowl-or funnel-shaped depressions) that may function as 'small natural features' with a disproportionately large role in maintaining biodiversity relative to their size. We assessed the diversity of microclimates, soils and vegetation and their relationships in six microhabitats (south-facing slopes, east-facing slopes, west-facing slopes, north-facing slopes and bottoms of dolines, and the adjacent plateau) for nine large dolines in a grassland ecosystem. Although there were remarkable differences among the conservation value of these microhabitats (e.g., representation of different species groups, presence of 'climate relicts'), each microhabitat had an important role in maintaining species that are rare or absent in other microhabitats in the landscape. We found that the studied dolines exhibited highly variable environmental conditions and promoted a high diversity of vegeta-tion types with unique species composition, contributing to the topographic, climatic, soil, vegetation and land cover heterogeneity of karst landscapes. Therefore, our findings highlight that dolines may function as local biodiversity hotspots and have a crucial conservation importance. As dolines are widespread topographic features in many karst landscapes throughout the world, our results could be directly applied to other regions as well. An integrated approach is urgently needed to provide guidelines for landscape management, promoting the retention of the microhabitat di-versity of small natural features for species vulnerable to climate change and/or various disturbances.

Microrefugia are often located within topographically complex regions where stable environmental conditions prevail. Most of the studies concerning the distributions of climate change-sensitive species have emphasized the dominance of cold air pooling over other environmental factors, such as resource availability. There is a shortage of information on the relationships among topography-related microsite diversity, microclimate, resource availability, and species composition in microrefugia. To fill this knowledge gap, we studied the effects of microclimatic conditions and soil resources on plant species occurrence within and adjacent to 30 large topographic depressions (i.e., dolines) in two distant karst regions. Our results showed that both microclimate and soil resource availability may play a key role in maintaining climate change-sensitive species and biodiversity in dolines; therefore, they may simultaneously act as climate and resource microrefugia. Establishing climate-smart conservation priorities and strategies is required to maintain or increase the refugial capacity of such safe havens.

Wood-pastures harbor critical natural and social values and are among the most ancient land use forms of Europe. The crucial conservation value of these silvopastoral systems is generally contributed to their characteristic landscape elements, the solitary trees, which provide microhabitats for a variety of organisms. However, by accommodating four habitat types (grasslands, solitary trees, forests, and forest edges) on a relatively small spatial scale, wood-pastures might host functionally and compositionally distinct arthropod communities, thus enhancing the landscape-level biodiversity. To test this, we assessed the fine-scale microclimatic conditions of the four different habitat types of three wood-pastures and investigated the effects of these conditions on ant activity and community organization patterns. Besides microclimate, niche breadths (quantified by four-dimensional niche hypervolumes), niche overlaps, and interspecific interactions were also considered to assess the importance of interspecific competition in shaping the studied ant communities. The four habitat types showed notable differences in the previous aspects, which resulted in different patterns of ant activity and community organization. Posing ideal conditions (high solar irradiance and temperatures above 25 °C) for ant activity, the grasslands were monopolized by usually 2-3 dominant species with large hypervolumes, while the subordinates mostly occurred under environmental extremities. Despite their vicinity to the grasslands, solitary trees showed a different pattern, where in total 8 subordinate species associated with specific microclimates were present. The forest edges hosted the most species-rich communities, with 18 species in total, where interspecific interactions played a major role in shaping the activity patterns. A similar result was obtained for forests, although the mild environmental conditions of these habitat types resulted in low overall ant activity. Our results unveil that by posing various microclimatic and structural conditions, wood-pastures enable the coexistence of four ecologically and functionally distinct communities, which makes them ideal targets for biodiversity conservation.

Species can survive periods of unfavorable conditions in small areas that are protected from climate-related disturbances, such as increasing temperature and severe drought. These areas are known as “microrefugia” and are increasingly recognized by conservationists. Although some studies suggest that the in situ survival of invertebrate species may be mediated by topographically complex environments, there is little information about the main environmental factors that drive species distributions within such areas. Here, we investigate the spatial patterns and species trait composition (moisture preference, body size, dispersal capacity, and feeding habit) of five groups of ground-dwelling arthropods—spiders, woodlice, ants, ground beetles, and rove beetles—in topographic depressions (i.e., “solution dolines” or “solution sinkholes”) and on the surrounding plateau within a forested karst landscape and analyze the microhabitat conditions that affect these arthropod assemblages. We found that dolines have the capacity to maintain characteristic arthropod assemblages—including species that may be particularly vulnerable to climate change (e.g., species associated with moist habitats)—and thus, they may contribute to the landscape-scale biodiversity of karst landscapes. We also found that doline bottoms have the potential to maintain permanently moist conditions not only in spring and autumn but also during drier periods of the year. This ability of dolines may indicate the presence of potential hydrologic microrefugia. Furthermore, dolines displayed specific sets of species traits (e.g., more small-bodied spiders, more carnivorous ground beetles, and more rove beetles with high dispersal capacity occurred in dolines than on the plateau), highlighting that they may facilitate the persistence of some species and traits that are purged from the surrounding landscape. Future studies may reveal the long-term ecological consequences of different climatic and anthropogenic factors on the distribution and functional traits of arthropod taxa within microrefugia and on the refugial capacity of these safe havens under a warming climate.

Biological invasion is a worldwide phenomenon that can be considered a natural hazard. Protection against invasive plant species can only be successful if we know the anthropogenic factors that influence their occurrence, such as changes in land cover. In our study, we investigated the LUCAS based spatial distribution of five common invasive plant species (2015) and its connections with the recent (2012-2018) land CORINE based cover changes. The LUCAS points infected with this species are much closer to the CORINE land cover change polygons than the non-infected points. Our results suggest that the occurrence of Asclepias syriaca, Solidago spp, Ailanthus altissima and Robinia pseudoacacia is significantly dependent on whether land use has changed in the vicinity of LUCAS points infected with these species. Only the occurrence of Elaeagnus angustifolia does not show any correlation with changes in land cover.

Invasive species are a major threat to biodiversity worldwide. Controlling their rapid spread can only be effective if we consider the geographical factors that influence their occurrence. For instance, roads, railway networks, green and blue infrastructure, and elements of ecological networks (e.g., ecological corridors) can facilitate the spread of invasive species. In our study, we mapped the occurrence of five invasive plant taxa (tree of heaven, common milkweed, Russian olive, black locust, and goldenrods) in Hungary, using field photos from the EUROSTAT Land Use and Coverage Area Frame Survey (LUCAS) database from the year 2015. Species point occurrence data were compared with the spatial characteristics of linear transport infrastructure and with the green and blue infrastructure. We found that the occurrence of tree of heaven and Russian olive was strongly related to the road and railway network. The average Euclidean distance of LUCAS points infected with these species from railway embankments and roads was much smaller than that of uninfected points. However, black locust and goldenrods were more common only along the road network. According to our results, the occurrence of some investigated invasive plants was over-represented in the HEN and within Natura 2000 areas of Hungary compared to non-infected points. Our results may provide important information for predicting the rate of invasion and for applying targeted management within the HEN, and Natura 2000 protected areas.

Microrefugia are small areas that support favourable climate and allow species to persist during regional and global climate changes. Dolines in karst landscapes may provide such areas for many climate change-vulnerable species. Here we provide a better understanding on how plant species indicate changes in their environment (temperature, soil moisture and light availability) after a few years of partial canopy removal from dolines and their close surroundings (logged areas: >1 ha). We place our results in the context of the most widely used forest management practices within the study area (Mecsek Mts, Hungary), in addition to presenting a general framework for the maintenance of doline microrefugia in forested karst landscapes. Three types of habitats were investigated: dolines before logging, dolines after logging, and the forested plateau. Three large dolines and three sites on the plateau were selected for vegetation sampling. All dolines were sampled before logging and 5-10 years after partial canopy removal. Logging resulted in a 50-80% reduction of canopy cover in the dolines and their close surroundings. We established a transect across each doline from north to south passing through doline bottoms, and across each plateau site. We estimated the percentage cover of vascular plant species (tree saplings - up to 1 m in height, shrubs and herbs) along the transects using 1 m x 1 m vegetation plots, determined the diagnostic species of the doline and plateau habitats, and used multivariate methods and linear mixed-effects models during analyses. Plant species indicated clear gradients of the main microclimatic factors within the dolines and that significant changes took place after logging. Canopy removal caused substantial changes in the main microclimatic factors of most doline microhabitats (e.g., south-facing slopes). The vegetation of the dolines before logging indicated moister conditions than that of the plateau and cooler and shadier conditions than that of the dolines after logging. These and our previous results suggest that logging may directly and indirectly influence dolines to be microrefugia under global warming. By applying our framework to refugia conservation and management for the karst landscape in the Mecsek Mts, we can conclude that the protection of old forests and natural forest dynamics in as many large dolines as possible and the implementation of close-to-nature forestry practices may be essential to maintain regional biodiversity in the long run.

Karst depressions (dolines) have the potential to act as safe havens for a high diversity of valuable species. We showed that local anthropogenic disturbances play a significant role in determining the naturalness of dolines. We compared the number of specialist species, competitor species, generalist species and species of disturbed habitats between natural and disturbed dolines in two Hungarian karst areas, where different types of anthropogenic disturbances have been shaping the vegetation for centuries. We found that these disturbances have the potential to negatively influence the naturalness of dolines, reducing the number of valuable species, thus affecting the conservation value of dolines. To maintain the naturalness of vegetation in these doline habitats, the populations of ruderal competitors should be eliminated, and sustainable forest management should be adapted. However, there are still open questions about the effects of different disturbances on the naturalness in dolines that need to be answered to determine which conservation strategies will be particularly suitable for valuable species in a warming climate.