High-resolution ecosystem maps increase the efficiency of policy implementation. However due to challenges related to both data and methods, such maps of appropriate scale and quality are still rarely available for nationwide analyses. We present solutions to some typical challenges of national-scale ecosystem mapping through the new Ecosystem Map of Hungary. It is a comprehensive, spatially and thematically detailed map with a hierarchical typology. The mapping methodology combined several novel elements from the integration of various large-scale databases in a (theoretical) data cube to the use of image-based predictive mapping (with a Random Forest classifier, using Sentinel 1-2 and environmental data). A participatory method involving local experts was used for validation, addressing the lack of suitable reference data as well as improving map-maker - map user interaction. Besides the original objective of supporting conservation-related decision-making, further uses emerged from a variety of fields including spatial planning, education and recreation.

Invasion of alien species is one of the main drivers of land degradation threatening both natural and managed ecosystems. Ecological restoration is crucial in controlling invasion to improve biotic resistance and avoid further land degradation. We investigated the possibility of controlling the establishment of invasive alien species (IAS) by native seed addition. We tested if trait similarity or increased propagule pressure of native species results in the suppression of IAS at the early stage of development. We set up a sowing experiment with three widespread IAS in Hungary of different life forms and functional groups (Asclepias syriaca, Conyza canadensis, Tragus racemosus) and four Pannonic sand grassland species (Festuca vaginata, Galium verum, Gypsophila paniculata, Saponaria officinalis). We found no significant differences in germination ability and seedling emergence between native species and IAS, despite the differences in thousand‐seed weight. Using univariate general linear models, we found that the seedling establishment of IAS can be reduced by adding native species at high densities but also depending on the species identity. Instead of species of similar traits, the seeding of a competitor perennial grass of sand grasslands (F. vaginata) reduced the seedling emergence of all studied IAS the most. Our results confirm that IAS can be effectively controlled by native seed addition in the early establishment stage, especially applying higher densities and competitive species. We conclude that invasion‐resistant restoration can be achieved by the combination of several factors, including high‐density sowing of native species that match IAS in the early stage of development.

The restoration of invasion-resistant plant communities is an important strategy to combat the negative impacts of alien invasions. Based on a systematic review and meta-analysis of seed-based ecological restoration experiments, here we demonstrate the potential of functional similarity, seeding density and priority effect in increasing invasion resistance. Our results indicate that native priority is the most promising mechanism to control invasion that can reduce the performance of invasive alien species by more than 50%. High-density seeding is effective in controlling invasive species, but threshold seeding rates may exist. Overall seeding functionally similar species do not have a significant effect. Generally, the impacts are more pronounced on perennial and grassy invaders and on the short-term. Our results suggest that biotic resistance can be best enhanced by the early introduction of native plant species during restoration. Seeding of a single species with high functional similarity to invasive alien species is unpromising, and instead, preference should be given to high-density multifunctional seed mixtures, possibly including native species favored by the priority effect. We highlight the need to integrate research across geographical regions, global invasive species and potential resistance mechanisms.

To preserve the natural genetic pattern of species and to avoid the introduction of nonadapted ecotypes during restoration, seed transfer should be spatially restricted. Instead of applying administrative borders in the absence of species‐specific empirical data, biogeographical knowledge can be used as a proxy. Hungary was used as a suitable test region for this approach. The aims of the study were (1) to produce an evidence‐based seed transfer zone (STZ) map applying the Multiple Potential Natural Vegetation model; (2) to assess the uncertainty of the resulting STZ map; and (3) to compare the present seed transfer regulation based on administrative regions with the evidence‐based STZ map. The analysis was based on a floristic map, a vegetation map, and a landscape map of Hungary. Intersected polygons of the three maps were filled with Multiple Potential Natural Vegetation data and clustered to produce seven contiguous units that can serve as STZs. The uncertainty analyses provided a numerical comparison between the two approaches and demonstrated the inadequacy of defining administrative regions as STZs. The practical result of the study is the production of an evidence‐based STZ map that could replace the administrative map currently used for regulation in Hungary. Moreover, this map helps to develop native seed propagation and to enhance ecological restoration. We conclude that field‐based potential vegetation models, similar to the Multiple Potential Natural Vegetation, are suitable for STZ development in countries lacking an evidence‐based system for seed transfer.

Invasive species are among the main threats to grassland biodiversity, and nature conservation management seeks the best methods to eliminate them and to restore natural habitats. We studied the long‐term effect of mowing on the restoration of Pannonian sand grassland after elimination of invasive black locust (Robinia pseudo‐acacia) plantation in Hungary, Europe. Stands of R. pseudo‐acacia at three sites were felled and stumps herbicide‐treated in the winter of 1994–1995. Mowing with hay removal treatment was applied twice a year in 1995–2001 to assist grassland recovery. A block of 12 adjacent plots of 10 m by 10 m was assigned for the experiment at each site, with six control (unmowed) and six treatment (mowed) plots randomly selected. Vegetation was sampled in June and August yearly in 1995–1999 in all sites, plus in seminatural reference grasslands then re‐sampled six times until 2017 in two sites. Herbicide application with repeated mowing successfully eliminated R. pseudo‐acacia. In the unmowed plots, dense woody cover developed at all sites. Vegetation of mowed plots approached the reference grasslands in sites with better propagule availability of target species according to trajectory analyses. In these sites, higher cover of target species was found in mowed compared to unmowed plots, though still significantly lower than in the reference. Mowed plots were more prone to secondary invasion than the unmowed. The long‐term monitoring revealed that initial mowing assisted the restoration of Pannonian sand grassland, but further management is needed to control secondary invasion and increase target species cover.