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The aim of the study was to estimate changes in the floristic composition near Svýcarna lodge (1304 m a.s.l.), where cattle grazing after a long-term management cessation was introduced on a pasture area of 3.6 ha in 2012. The pasture was divided into two grazing sub-localities: P1 (Nar) with dominance of Nardus stricta and Avenella flexuosa and P2 (Des) with dominance of Deschampsia cespitosa. For grazing, Highland Cattle was used with a stocking rate up to 1 livestock unit per ha and year. The floristic composition was evaluated and statistically analyzed. After six years of restored grazing the overall species richness enhanced and a higher dominance of rare and endangered species was found. The dominance of some common species like Vaccinium myrtillus, and Calamagrostis villosa tended to decrease within a grazing period in favor of new species colonisation.

11 Pág., Over the last 30 years, many studies have surveyed weed vegetation on arable land. The 'Arable Weeds and Management in Europe' (AWME) database is a collection of 36 of these surveys and the associated management data. Here, we review the challenges associated with combining disparate datasets and explore some of the opportunities for future research that present themselves thanks to the AWME database. We present three case studies repeating previously published national scale analyses with data from a larger spatial extent. The case studies, originally done in France, Germany and the UK, explore various aspects of weed ecology (community composition, management and environmental effects and within-field distributions) and use a range of statistical techniques (canonical correspondence analysis, redundancy analysis and generalised linear mixed models) to demonstrate the utility and versatility of the AWME database. We demonstrate that (i) the standardisation of abundance data to a common measure, before the analysis of the combined dataset, has little impact on the outcome of the analyses, (ii) the increased extent of environmental or management gradients allows for greater confidence in conclusions and (iii) the main conclusions of analyses done at different spatial scales remain consistent. These case studies demonstrate the utility of a Europe-wide weed survey database, for clarifying or extending results obtained from studies at smaller scales. This Europe-wide data collection offers many more opportunities for analysis that could not be addressed in smaller datasets; including questions about the effects of climate change, macro-ecological and biogeographical issues related to weed diversity as well as the dominance or rarity of specific weeds in Europe., This work was made possible via the Weeds and Biodiversity working group of the European Weed Research Society. This project was funded under a Rothamsted Research and BBSRC grant number BB/W510543/1. Helen Metcalfe was partly supported by the Natural Environment Research Council (NERC) and the Biotechnology and Biological Sciences Research Council (BBSRC) research programme NE/N018125/1 LTS-M (ASSIST). Jana Bürger's work on this project was supported by Deutsche Forschungsgemeinschaft DFG (grant number BU 3097/1-1).

Questions: Two scientific disciplines, vegetation science and weed science, study arable weed vegetation, which has seen a strong diversity decrease in Europe over the last decades. We compared two collections of plot-based vegetation records originating from these two disciplines. The aim was to check the suitability of the collections for joint analysis and for addressing research questions from the opposing domains. We asked: are these collections complementary? If so, how can they be used for joint analysis?. Location: Europe. Methods: We compared 13 311 phytosociological relevés and 13 328 records from weed science, concerning both data collection properties and the recorded species richness. To deal with bias in the data, we also analysed different subsets (i.e., crops, geographical regions, organic vs conventional fields, center vs edge plots). Results: Records from vegetation science have an average species number of 19.0 ± 10.4. Metadata on survey methodology or agronomic practices are rare in this collection. Records from weed science have an average species number of 8.5 ± 6.4. They are accompanied by extensive methodological information. Vegetation science records and the weed science records taken at field edges or from organic fields have similar species numbers. The collections cover different parts of Europe but the results are consistent in six geographical subsets and the overall data set. The difference in species numbers may be caused by differences in methodology between the disciplines, i.e., plot positioning within fields, plot sizes, or survey timing. Conclusion: This comparison of arable weed data that were originally sampled with a different purpose represents a new effort in connecting research between vegetation scientists and weed scientists. Both collections show different aspects of weed vegetation, which means the joint use of the data is valuable as it can contribute to a more complete picture of weed species diversity in European arable landscapes., The work on this project was supported by Deutsche Forschungsgemeinschaft DFG (grant number BU 3097/1-1 for Jana Bürger), Czech Science Foundation (grant number 19-28491X for Milan Chytrý and Zdeňka Lososová), and by Slovenian Research Agency (research core funding No. P1-0236 for Urban Šilc and Young researcher programme for Filip Küzmič).

Three plot field trials (2014–2017) were carried out in Prague. The aim of the study was to evaluate the efficacy of herbicides against volunteers from Clearfield® (CL) and conventional oilseed rape (Brassica napus L.) in winter wheat (Triticum aestivum L.) and to quantify the effect of herbicide and application time on wheat yield. Autumn control (diflufenican, isoproturon, flumioxazin, metribuzin, penoxsulam, florasulam, chlorsulfuron were tested) of volunteer oilseed rape (OSR) was more effective than using the spring herbicide treatments (2,4-D, iodosulfuron, amidosulfuron, tritosulfuron, florasulam), especially against the CL OSR variety. Full control of both CL and conventional OSR was recorded only on plots treated by the combination of metribuzin + diflufenican + flufenacet. The most effective spring herbicide was 2,4-D, but its efficacy (82–95%) depended on the growth stage of OSR and application rate. Efficacy of spring herbicides against CL OSR was lower compared to that against conventional OSR, but there were large differences among tested herbicides. Efficacy of tested ALS inhibitors against volunteer CL OSR ranged between 20% (chlorsulfuron) and 77% (tritosulfuron + florasulam). Seed production of volunteer OSR ranged between 0 and 37,000 seeds m−2 while depending strongly on time of sowing and weather conditions during the autumn and winter. No seed of CL OSR matured on plots treated by metribuzin in autumn or 2,4-D at application rate 377 g ha−1 in spring. Volunteer OSR in competition with winter wheat caused almost 50% wheat yield loss on the untreated check. Although the efficacy of most spring herbicide treatments on conventional OSR was good, the competition effect of OSR on wheat during winter and early spring caused about 0.52–0.86 t ha−1 greater yield loss compared to autumn herbicide treatments.

Precipitation and irrigation strongly affect herbicide management of vegetables, especial fast- growing vegetables as a kohlrabi. The objective of this study was to compare the effects of irrigation and paraffin oil-based soil adjuvant on the efficacy and selectivity of pendimethalin and metazachlor herbicides and their tank-mix combination in kohlrabi. Small plot experiments were carried out in Prague, Czech Republic during 2015 and 2016. Herbicide efficacy on Chenopodium album, Mercurialis annua, and Solanum physalifolium was significantly affected by irrigation shortly after herbicide application, but the efficacy, visual phytotoxicity, as well as both aboveground and root kohlrabi biomass were not affected by the adjuvant. Pendimethalin caused significantly greater phytotoxicity than did metazachlor. Aboveground biomass of kohlrabi plants treated with pendimethalin was about 20–50% less compared to that of plants grown on hand-weeded plots, similar as a tuber yield (tuber weight was about 30% lower). Heavy irrigation shortly after the application of pendimethalin did not affect selectivity of this herbicide treatment. On the contrary, selectivity of metazachlor was strongly affected by irrigation and natural precipitation. Weight of tubers harvested on plots treated by pendimethalin was the same or lower compared to that from plots with competition of annual weeds. The lowest yield (50% compared to hand-weeded check) was on the plots treated by herbicide mixture pendimethalin + metazachlor and irrigated shortly after the application.

Long-term national European weed surveys, large scale classical phytosociological programs and camera-based documentation systems lead to results which can be documented in form of maps. Comparisons of these visual representations of relative weed positions can be used for the prediction of changing weed spectra and of plant biodiversity changes. Statistical methods connected with mapping software are used for the analysis of environmental factors and of farm managing practices influencing the occurrence of weeds. Maps produced by sensor-driven weed detection devices still differ considerably from maps produced via classical phytosociological approaches. Computer algorithms may allow the precise identification of some weeds in camera images. The present technical solutions are, however, still far from those achieved by experienced botanists. Many weed detection tools based on algorithms are not able to distinguish between closely related weeds yet. A few European countries have a long tradition of surveying weeds in major crops by traditional tools. Various software packages are employed for the analysis, documentation and visualisation of survey results. Large scale comprehensive maps including the infestation of crops over different countries are, however, often biased as not every national research group uses the same methods for the assessment of weed infestation. The ranking of the most common species seems, however, to allow comparable conclusions. The recognition of trends in spectrum changes can only be derived from long term studies as we see it. Our review reflects discussions within the Weed Mapping Working Group of the European Weed Research Society over the last ten years. We try to identify new research trends and to respond accordingly with new research projects. What we see today is a shift from traditional mapping approaches towards the use of digital devices as for example in precision farming projects. Another issue of increasing importance is the mapping of herbicide resistant biotypes.

Parasitoid wasps of the Polysphincta genus-group are highly specialised on their spider hosts, and most of them are known to manipulate their hosts into building a special web in which the parasitoid pupates. Trophic niche and the plasticity of host use were investigated in the koinobiont parasitoid Zatypota kauros Gauld from Queensland, Australia. We found that Z. kauros attacks spider hosts from different families, each differing widely in their web-building behaviours, which makes it unique in the breadth of its host range. Molecular analyses revealed that the taxon Z. kauros contains three divergent mitochondrial lineages. Lineage A was associated exclusively with spiders of the genus Anelosimus (Theridiidae), which builds tangle webs; lineage B was associated with the genus Cyrtophora (Araneidae), which weaves tent webs; and lineage C was associated with a broad range of hosts, including spiders of both the families Araneidae and Theridiidae. Unique host manipulations could be observed in the web-building behaviours of the different host groups. Nevertheless, nuclear data from two ribosomal genes and three introns did not add any support to the existence of different evolutionary lineages, nor did they coincide with the different host groups. The partial correspondence of mitochondrial lineage and host use, together with an apparent mito-nuclear conflict might indicate maternal effects or very recent and/or incomplete speciation in this taxon. Given their wide host range and intriguing interactions with their hosts, the Z. kauros complex represents a promising system for studying parasitoid specialisation and its potential impact on speciation.

Polysphinctine wasps are exclusive parasitoids of spiders and their host utilisation strategies are highly taxonomically specific. In this study, the host utilisation of two Australasian parasitoid wasps of the genus Eriostethus was studied for the first time. Our study revealed considerable differences in host-parasitoid interactions between Eriostethus minimus associated with 3D tangle web-building spiders from the family Theridiidae (new family record for Eriostethus) and E. perkinsi associated with 2D orb-web weaving spiders from the family Araneidae. A pupa of the former species was located in a spider retreat in the centre of an unmodified 3D tangle web and the pupal cocoon had a sparsely woven and partially transparent wall. In contrast, a cocoon of the latter species was suspended at the centre of a modified irregular sparse 3D cocoon web and the pupal cocoon had a strong, densely woven cocoon wall. This difference in host utilisation is not in agreement with the synonymisation of Millironia with Eriostethus.

“Arable Weeds and Management in Europe” is a collection of weed vegetation records from arable fields in Europe, initiated within the Working Group Weeds and Biodiversity of the European Weed Research Society (EWRS). Vegetation-plot data from this scientific community was not previously contributed to databases. We aim to prove the usefulness of collection for large scale studies through some first analyses. We hope to assure other weed scientists who have signalled willingness to share data, and plan to construct a full data base, making the data available for easy sharing. Presently, the collection has over 60,000 records, taken between 1996 and 2015. Many more studies for potential inclusion exist. Data originate mostly from studies exploring the effect of agricultural management on weed vegetation. The database is accompanied with extensive meta-data on crop and weed management on the surveyed fields. The criteria for inclusion were a minimum amount of information on the cultivated crop, and a georeference. Most fields were surveyed repeatedly, i.e. transects, multiple random plots, or repeated visits. All surveys aimed to record the complete vegetation on the plots. Sometimes, taxa were identified only to genus level, due to survey dates very early in the vegetation period. Plant taxonomy is standardized to the Euro+Med PlantBase., B. was funded by Deutsche Forschungsgemeinschaft under the grant number BU 3097/1-1.

Neophytes belong to a group of non‑native plants, which were introduced by man either intentionally or unintentionally in different ways. The discovery of America is a historical milestone for non-native plant research. Most scientists use the term neophyte for species introduced after the year 1500. Neophytes became progressively more numerous in arable fields and their proportion significantly increased during the second half of the 20th century. The aim of this study was to assess the occurrence of neophytes in arable fields in the Czech Republic in terms of applied management systems, crops, and environmental site conditions at different altitudes. In the years 2006 to 2008, a phytocoenological survey was conducted on selected farms across the Czech Republic under various climate and soil conditions in spring and winter cereals and in wide‑row crops. Totally, 172 weed species were found. Among these species, 8 % were considered as neophytes (13 species). In respect of their stage of invasiveness, 6 neophytes were considered as invasive, 6 species as naturalized and 1 species was considered as casual. Frequencies of neophyte species we found ranged between 0.3 – 31 % from all relevés. Environmental site conditions associated with altitude were the most important factors correlated with the occurrence of neophytes. The incidence of neophytes is primarily concentrated at lower altitudes and is mainly associated with stands of spring wide‑row crops, especially root crops and vegetables. A higher proportion of neophytes was found in organic farming.

The impact of eight herbicides in different residual stages on the predatory activity of a potential biological control agent, the wolf spider Pardosa agrestis, was studied in the laboratory. We found that fresh wet residues of all tested herbicides negatively affected the total and cumulative predatory activity of this species. Moreover, treatment with 48-h-old residues of the glufosinate ammonium herbicide Basta induced a significant increase in predatory activity in P. agrestis, presumably as a consequence of hormesis. These results imply that the natural pest control provided by the agrobiont spider P. agrestis can be weakened by the application of the studied herbicides. On the basis of our results, we suggest that sublethal effects on beneficial organisms should be considered in the planning of weed management of agroecosystems and should not be omitted from the herbicide registration process.

Lycosid spiders are among the most abundant and diverse insectivores occurring in all agroecosystems. Certain pest management practices, such as the application of pesticides, can disrupt their role in insect pest control. Therefore, understanding the effects of pesticides, including sublethal effects, is essential for the assessment of chemical effects on beneficial arthropods. We investigated the sexual chemical communication of the beneficial agrobiont spider Pardosa agrestis and its disruption by two widely used pesticides, the glyphosate-based herbicide Roundup and the pyrethroid-based insecticide Nurelle D. A two-choice olfactometer and Y-maze were used to study the effectiveness of female airborne and dragline pheromone cues and the disruptive effect of the pesticides. Males of P. agrestis did not locate females via airborne cues, but were very receptive to female dragline silk and male dragline silk. When both female dragline silk and male dragline silk were provided at the same time, the males preferred female silk. Pesticide treatments significantly affected the male ability to follow female cues deposited on dragline silk. The 3-h residues of both Roundup and Nurelle D significantly disrupted the male ability to follow female cues deposited on dragline silk. Treatment by 48-h residues significantly disrupted the male ability only in the case of Nurelle D. Our results demonstrate that pesticides reduce the ability of male spiders to search for a mate due to the disruption of the male's ability to detect the silk cues of the female.

The main aim of the present study was to evaluate benefits of the new technology of sugar beet varieties tolerant to foramsulfuron (FSN) + thiencarbazone-methyl (TCM) herbicides commercialised as Conviso® Smart (four weed management strategies were tested) compared to conventional herbicides (two weed management strategies). Plot-field trials were carried out in Prague (Czech Republic) in 2016–2019. Efficacy on Chenopodium album L., Amaranthus retroflexus L., Echinochloa crus-galli (L.) P. B., Abutilon theophrasti Med. and weed beet were evaluated. FSN + TCM controlled all tested weeds very well (efficacy more than 97%) in case of split application with an oil adjuvant. When only one application of FSN + TCM was performed in dry weather conditions, efficacy on C. album and A. theophrasti was insufficient (less than 90%). FSN + TCM fully controlled weed beet at all tested weed management strategies in all experimental years and a residual activity of this herbicide did not allow new plants to emerge. The conventional tank-mixes (TM) controlled C. album and A. retroflexus well (efficacy more than 96%). Efficacy of conventional TM on E. crus-galli ranged from 78 to 100%. Efficacy on A. theophrasti was affected by herbicides used and weather conditions, but did not exceed 92% with either of the conventional TM. The tested conventional herbicides were not able to control weed beet. A relatively high reproductive ability of C. album and A. retroflexus (13,000–157,000 and 7000–10,000 seeds m−2, respectively) was seen in plots where these weeds were not fully controlled. The seed production of A. theophrasti was relatively low (not exceeded 25,000 seeds m−2). However, mature seeds were present in most plots. The reproductive ability of E. crus-galli in sugar beet canopy was much lower (200 - 1800 seeds m−2) compared to the other species, due to its late emergence. Weed beet competed with sugar beet only when other weeds were controlled and weed beet survived the treatment. In these plots, fruit production of weed beet was significantly higher (5000–75,000 fruits m−2). The highest sugar beet yields (78–100 t ha−1) were in weed-free plots or plots with a low weed infestation (split application of FSN + TCM). A significantly lower yield (45–52 t ha−1) was recorded when C. album and A. theophrasti were not sufficiently controlled. In plots where the weed beet was the only weed not controlled, sugar beet yield ranged from 23 to 61 t ha−1. The lowest sugar beet yield (less than 10 t ha−1) was observed in untreated plots where mainly C. album and A. theophrasti predominated. There was a negative relationship between sugar beet yield and total weed biomass.

This paper reports on the current situation in weed vegetation composition on arable land in selected areas of the Czech Republic, assessment of influence of selected variables: applied management systems (conventional, organic), crops (winter cereals, root crops) and altitude and ranking of the importance of these particular factors. A phytocoenological survey was conducted from 2006 to 2008 during a vegetation period using releves that were 100 m 2 in size, placed in the central part of fields. In total, 202 releves of agricultural vegetation were recorded. The combined environmental variables explained 10.6% of the variability. Based on the pCCAs, the highest effect was found at altitude, which explains 5.1% of the species composition variability. The second and third most significant factors are crop and management system, which explain 3.3% and 1.8% of the variability, respectively. The lowlands were generally characterised by the thermophilous summer annual weed species. The higher altitudes were populated by species that are typical for colder areas and poor, humid, and acidic soil types, such as cambisoil.

Summary This article documents the impact of site conditionsand farming practices on the occurrence of rare andendangered weeds on arable land in the Czech Republic.A survey was conducted between 2006 and 2008 inwinter cereals, spring cereals and wide-row crops. Therelationship between the occurrence of plants andexplanatory factors was analysed using a multivariateanalysis to calculate species frequencies in differenttypes of farming, crops and altitudes. In total, 290releves were recorded, with a total number of 172weed species. Nineteen weeds, classified as rare andendangered species according to the national Czechlist, were identified in 106 releves. The highest effecton the occurrence of rare and endangered weed specieswas observed for altitude. Almost half of the recordedendangered and rare species belonged to thethermophilous weed vegetation typical for cereals onbasic soils. A higher occurrence of endangered spe-cies has been confirmed for organic farming, wherethe sum of frequencies was 4.5 times higher than inconventional farming. Field size was not included inour analyses, but could be a factor affecting weedassemblages. The highest frequency of rare specieswas recorded in spring cereals, followed by wintercereals and wide-row crops. Higher numbers wereidentified within fields with higher weed coverage.Lower farming intensity and diversified farming sys-tems at higher altitudes provided better conditionsfor the occurrence of rare species than intensivelyfarmed lowlands.Keywords: red list species, conventional farming,organic farming, altitude, crop, syntaxon, frequency,weed cover.K

This paper reports on the within-habitat (α) and on the between-habitat (β) diversity of weed vegetation on arable land in the Czech Republic, influenced by management systems, crops grown and altitude. A phytocoenological sur vey was conducted from 2006 to 2008 during a vegetation period using releves that were 100 m 2 in size, placed in the central part of fields. The species richness and the mean Sorensen dissimilarity were calculated. The statistically sig nificant effects of the type of farming and altitude on species richness were recorded. The average species numbers in one releve reached 9.17 and 21.17 in conventional and organic farming, respectively. In both management systems, an increasing number of species was recorded with increasing altitude. Statistically significant effects of all the vari ables were observed when evaluating β-diversity. Higher β-diversity was found in conventional farming.