Laufkäfer in der Aare-Aue Rupperswil, Kanton Aargau, in den ersten fünf Jahren nach der Renaturierung (Coleoptera, Carabidae)

Ground beetles of the alluvial area Rupperswil, Canton Aargau, Switzerland, during the five years after its restoration (Coleoptera, Carabidae) The Rupperswil floodplain (Canton Aargau) was restored in the years 2010–2011. From 2012 to 2016, annual surveys of ground beetles were conducted. Over the five years, a total of 116 species were collected. From these species, 12 are classified as threatened, near threatened, or rare according to the Red List of Switzerland. Moreover, considerable numbers of Bembidion atrocaeruleum, B. prasinum, and Harpalus progrediens were found in the Rupperswil floodplain, for which the Canton Aargau has a particularly high responsibility for conservation. Additionally, 37 of the recorded species are character species for floodplains. Thus, the restoration can be considered very successful for ground beetles. Non-restored areas, characterized by river training measures, harbor generally half as many species at best. The number of species recorded per year varied between 68 and 82. Species turnover rate was between 28 and 45%. This reflects the change in habitats and hydrology over the five years. Open gravel/sand surfaces and annual ruderal habitats were reduced to one-third of their original area, while reed canary grass stands and perennial ruderal habitats tripled in size. On the other hand, the turnover is certainly also due to the low detection probability of rare species. Despite the strong decline in individual ground beetle species which typically occur on open gravel surfaces, it would be premature to initiate interventions to rebuild such areas. During the last year of the study, all typical gravel species observed in the previous years within the study area were found again. If anything, it would be more beneficial to build ponds with flat banks of fine sand within the forested sections of the floodplain or clear some patches to create more ruderal areas. RÉSUMÉ La zone alluviale de Rupperswil (canton d’Argovie) a été renaturée dans les années 2010-2011. De 2012 à 2016, les carabes ont été recensés annuellement. Au total, 116 espèces ont pu être identifiées. Parmi celles-ci, 12 espèces sont considérées comme en danger, potentiellement en danger ou rare selon la Liste Rouge. 37 espèces sont des espèces indicatrices pour les zones alluviales. Ainsi, la renaturation peut être considérée comme très réussie pour les carabes. Dans les surfaces non renaturées avec une dynamique alluviale réduite, causé par des mesures de construction fluviales, la moitié des espèces peuvent au mieux être trouvées. En comparaison de la Suisse dans son ensemble, la responsabilité de l’Argovie est très élevée pour le maintien en particulier de Bembidion atrocaeruleum, très fréquent, de B. prasinum et de Harpalus progrediens nombreux à Rupperswil. Pour un même effort d’échantillonnage, le nombre d’espèces trouvées a varié entre 68 et 82 pour les deux années. Le degré de turnover d’une année à l’autre s’est situé entre 28 et 45%. Ceci reflète d’une part le changement des biotopes et une hydrologie variable sur les cinq ans. Les alluvions sans végétation et les surfaces rudérales annuelles ont diminué d’environ un tiers alors que les Phalaridions et les surfaces rudérales pluriannuelles ont triplé. D’autre part, le turnover doit aussi être attribué à la probabilité réduite de trouver les espèces rares. Malgré un fort recul de certaines espèces particulières qui apparaissent typiquement dans les gravières ouvertes, il serait prématuré de créer de nouveau de telles surfaces par des interventions. Toutes les espèces de gravière ont encore pu être trouvées dans la région la dernière année d’étude. Le cas échéant, l’installation d’étangs dans la forêt de la zone alluviale avec des surfaces à sédiments fins provenant des berges de même qu’un nouvel écorchement de surfaces partielles pour la création de couloirs rudéraux seraient favorables. ZUSAMMENFASSUNG Die Aue Rupperswil (Kanton Aargau) wurde in den Jahren 2010-2011 renaturiert. Von 2012 bis 2016 wurden jährlich die Laufkäfer untersucht. Insgesamt konnten 116 Arten nachgewiesen werden. Davon sind 12 Arten gemäss Roter Liste gefährdet, potenziell gefährdet oder selten. 37 Arten sind Auenkennarten. Damit kann die Renaturierung bezüglich der Laufkäfer als sehr erfolgreich bezeichnet werden. In Gebieten, wo die Auendynamik durch flussbauliche Massnahmen stark reduziert ist, findet man bestenfalls halb so viele Arten. Im gesamtschweizerischen Vergleich ist die Verantwortung des Kanton Aargau für die Erhaltung insbesondere von Bembidion atrocaeruleum, in Rupperswil sehr häufig, B. prasinum, sowie Harpalus progrediens, beide zahlreich, sehr hoch. Die Anzahl der in den einzelnen Jahren bei gleichem Sammelaufwand gefundenen Arten variierte zwischen 68 und 82. Die Turnover-Rate der Arten in den Folgejahren betrug zwischen 28 und 45%. Dies widerspiegelt einerseits die Veränderung der Lebensräume sowie die unterschiedliche Hydrologie in den fünf Jahren. Offene Kies-Sandflächen und einjährige Ruderalfluren sind auf ca. einen Drittel geschrumpft während sich Rohrglanzgrasbestände und mehrjährige Ruderalfluren verdreifacht haben. Andererseits ist der Turnover sicher auch auf die geringe Auffindwahrscheinlichkeit selten vorkommender Arten zurückzuführen. Trotz starken Rückgängen einzelner Laufkäferarten, die typischerweise auf offenen Kiesflächen vorkommen, wäre es verfrüht, solche Flächen durch Eingriffe wieder zu schaffen. Es konnten auch im letzten Untersuchungsjahr noch alle typischen Kiesbank-Arten im Gebiet nachgewiesen werden. Allenfalls förderlich wären die Anlage von Tümpeln mit flachen aus Feinsedimenten bestehenden Uferpartien im Waldgebiet der Aue sowie das erneute Abschürfen einzelner Teilflächen zur Schaffung von Ruderalfluren

The Historic Square Foot Dataset : outstanding small‐scale richness in Swiss grasslands around the year 1900

Grasslands host a significant share of Europe's species diversity but are among the most threatened vegetation types of the continent. Resurvey studies can help to understand patterns and drivers of changes in grassland diversity and species composition. However, most resurveys are based on local or regional data, and hardly reach back more than eight decades. Here, we publish and describe the Historic Square Foot Dataset, comprising 580 0.09-m2 and 43 1-m2 vegetation plots carefully sampled between 1884 and 1931, covering a wide range of grassland types across Switzerland. We provide the plots as an open-access data set with coordinates, relocation accuracy and fractional aboveground biomass per vascular plant species. We assigned EUNIS habitat types to most plots. Mean vascular plant species richness in 0.09 m2 was 19.7, with a maximum of 47. This is considerably more than the present-day world record of 43 species for this plot size. Historically, species richness did not vary with elevation, differing from the unimodal relationship found today. The data set provides unique insight into how grasslands in Central Europe looked more than 100 years ago, thus offering manifold options for studies on the development of grassland biodiversity and productivity

AgriWeedClim database: A repository of vegetation plot data from Central European arable habitats over 100 years

Aims: Arable habitats (i.e. fields, orchards, vineyards, and their fallows) were cre- ated by humans and have been essential elements in Central European landscapes for several millennia. In recent decades, these habitats have been drastically altered by changes in land use as well as agricultural practices and, more recently, by climate change. These changes have precipitated substantial changes in vegetation and their spatial and temporal trajectories have not yet been exhaustively studied. Here, we present the AgriWeedClim database —­ a new resource of vegetation plot (relevé) data of arable habitats in Central Europe. Location: Germany, Czech Republic, Slovakia, Switzerland, Liechtenstein, Austria, Hungary, Northern Italy, Slovenia, Croatia. Methods: Vegetation plot data were obtained from large repositories (e.g. European Vegetation Archive), specialized regional databases, colleagues and the literature. Data were then checked for completeness and standardized (e.g. taxonomy, nomenclature, crop types). Species were assigned native, archaeophyte (i.e. alien species introduced before c. 1492 CE) or neophyte (i.e. alien species introduced after c. 1492 CE) status. Results: The AgriWeedClim database version 1.0 contains georeferenced data from 32,889 vegetation plots sampled from 1916 to 2019. Conclusions: We provide an overview of this new resource and present example analyses to show its content and possible applications. We outline potential research questions including analysis of patterns and causes of vegetation changes in arable habitats from the early 20th century to the present

Farmland biodiversity and agricultural management on 237 farms in 13 European and two African regions

Farmland is a major land cover type in Europe and Africa and provides habitat for numerous species. The severe decline in farmland biodiversity of the last decades has been attributed to changes in farming practices, and organic and low-input farming are assumed to mitigate detrimental effects of agricultural intensification on biodiversity. Since the farm enterprise is the primary unit of agricultural decision making, management-related effects at the field scale need to be assessed at the farm level. Therefore, in this study, data were collected on habitat characteristics, vascular plant, earthworm, spider, and bee communities and on the corresponding agricultural management in 237 farms in 13 European and two African regions. In 15 environmental and agricultural homogeneous regions, 6–20 farms with the same farm type (e.g., arable crops, grassland, or specific permanent crops) were selected. If available, an equal number of organic and non-organic farms were randomly selected. Alternatively, farms were sampled along a gradient of management intensity. For all selected farms, the entire farmed area was mapped, which resulted in total in the mapping of 11 338 units attributed to 194 standardized habitat types, provided together with additional descriptors. On each farm, one site per available habitat type was randomly selected for species diversity investigations. Species were sampled on 2115 sites and identified to the species level by expert taxonomists. Species lists and abundance estimates are provided for each site and sampling date (one date for plants and earthworms, three dates for spiders and bees). In addition, farmers provided information about their management practices in face-to-face interviews following a standardized questionnaire. Farm management indicators for each farm are available (e.g., nitrogen input, pesticide applications, or energy input). Analyses revealed a positive effect of unproductive areas and a negative effect of intensive management on biodiversity. Communities of the four taxonomic groups strongly differed in their response to habitat characteristics, agricultural management, and regional circumstances. The data has potential for further insights into interactions of farmland biodiversity and agricultural management at site, farm, and regional scale

<scp>ReSurveyEurope</scp>: A database of resurveyed vegetation plots in Europe

AbstractAimsWe introduce ReSurveyEurope — a new data source of resurveyed vegetation plots in Europe, compiled by a collaborative network of vegetation scientists. We describe the scope of this initiative, provide an overview of currently available data, governance, data contribution rules, and accessibility. In addition, we outline further steps, including potential research questions.ResultsReSurveyEurope includes resurveyed vegetation plots from all habitats. Version 1.0 of ReSurveyEurope contains 283,135 observations (i.e., individual surveys of each plot) from 79,190 plots sampled in 449 independent resurvey projects. Of these, 62,139 (78%) are permanent plots, that is, marked in situ, or located with GPS, which allow for high spatial accuracy in resurvey. The remaining 17,051 (22%) plots are from studies in which plots from the initial survey could not be exactly relocated. Four data sets, which together account for 28,470 (36%) plots, provide only presence/absence information on plant species, while the remaining 50,720 (64%) plots contain abundance information (e.g., percentage cover or cover–abundance classes such as variants of the Braun‐Blanquet scale). The oldest plots were sampled in 1911 in the Swiss Alps, while most plots were sampled between 1950 and 2020.ConclusionsReSurveyEurope is a new resource to address a wide range of research questions on fine‐scale changes in European vegetation. The initiative is devoted to an inclusive and transparent governance and data usage approach, based on slightly adapted rules of the well‐established European Vegetation Archive (EVA). ReSurveyEurope data are ready for use, and proposals for analyses of the data set can be submitted at any time to the coordinators. Still, further data contributions are highly welcome.</jats:sec

Changes in arable weed communities over the last 100 years

During the last decades, agricultural practices have changed dramatically. Today, the fields are managed mechanically, and industrial fertilizer and herbicides are applied. This intensification has on one hand increased yields but on the other hand plants and animals living in the agricultural landscape were repressed or got extinct. Therefore, the introduction of agri-environmental schemes (wildflower strips, set-asides) was decided in Europe during the 1980s. These schemes were intended to promote the natural communities of arable fields. To show the changes in the arable flora in a bigger context, a meta-analysis was conducted for data across Europe. A meta-analysis compares the outcome of all traceable studies that were conducted on a specific topic. Hence, a reliable conclusion about the underlying effect can be drawn. Therefore, internet databases were searched for studies that were carried out on arable fields in Europe comparing historic and contemporary vegetation surveys. A total of 32 studies corresponded with the criteria, yielding 53 datasets. The studies compared vegetation surveys from 1939 to 2007. Averaged over these datasets the species number per plot of arable plants declined by about 20%. However, twelve of these datasets showed an increase in average species number per plot. All studies that started after 1980 showed an increasing average species number. Plant species preferring nutrient rich sites, neophytes, and monocotyledons largely increased since 1980, while species of typical arable weed communities declined. The change in species number was not influenced by crop type or study design. Furthermore, neither geographic location nor precipitation of the study region had an influence on the outcome of the meta-analysis. This temporal development of the European arable flora suggests that conservation measures, such as ecological compensation areas like unsprayed field margins or wild-flower strips, may have helped to some extent to “slow” the decline in species numbers, but not in terms of typical arable weeds like corn-cockle or cornflower. Hence, more specific measures should be taken to stop this decline, making sure that they are advantageous for rare arable species. Of course, it has to be taken into account that mainly threatened arable weeds and those plants beneficial for the farmer should be promoted. The growth of plants which bring a disadvantage for the production of agricultural goods should be prevented as much as possible

Dramatic decline in the Swiss arable flora since the 1920s

Arable weeds are among those groups of plants that are most threatened in Europe due to management intensification and efficient cleaning of crop seeds in modern agriculture. Plant species loss in arable fields had been assessed in many European countries about 30 years ago, and has gained renewed interest during the last few years. A rich historical data set on plots where arable weeds had historically been recorded in Switzerland enabled the study of changes in arable weed species since the 1920s onward. In total, 232 locations with historical plots were revisited. There, we recorded all plant species and their abundances on 100m2 plots. Across all plots the average number of species per plot declined dramatically by more than 60% during the last 90 years. Most species decreased in frequency, but common species stayed more frequent, while rare species − often characteristic weeds of traditionally managed crop fields − decreased in frequency or even disappeared. Plant groups with increasing species numbers and frequency were mostly neophytes, grasses and species with high nutrient demand. The above mentioned decline in species number and frequency of rare and characteristic weed species suggests that more effective conservation measures than hitherto taken are needed to ensure their preservation

Dramatic decline in the Swiss arable flora since the 1920s

Arable weeds are among those groups of plants that are most threatened in Europe due to management intensification and efficient cleaning of crop seeds in modern agriculture. Plant species loss in arable fields had been assessed in many European countries about 30 years ago, and has gained renewed interest during the last few years. A rich historical data set on plots where arable weeds had historically been recorded in Switzerland enabled the study of changes in arable weed species since the 1920s onward. In total, 232 locations with historical plots were revisited. There, we recorded all plant species and their abundances on 100m2 plots. Across all plots the average number of species per plot declined dramatically by more than 60% during the last 90 years. Most species decreased in frequency, but common species stayed more frequent, while rare species − often characteristic weeds of traditionally managed crop fields − decreased in frequency or even disappeared. Plant groups with increasing species numbers and frequency were mostly neophytes, grasses and species with high nutrient demand. The above mentioned decline in species number and frequency of rare and characteristic weed species suggests that more effective conservation measures than hitherto taken are needed to ensure their preservation

Arable weed seed bank of grassland on former arable fields in mountain regions

The changes in agricultural practice during the last century resulted in high-input farming in lowlands and the abandonment of crop fields in marginally profitable mountain regions. In Switzerland abandoned fields were converted into grassland. These fields had a rich historical flora and the few still existing fields still belong to the most species rich. As many arable weeds produce persistent seeds, abandoned fields should have a high potential to promote rare and threatened arable plants if tilled again. To test this hypothesis we collected 21 soil samples down to 20 cm depth in each the centre and the border of 38 abandoned fields. The centre and border samples of each field were each pooled, and afterwards the present seeds washed out. These seeds were then sown in pots and germination monitored in a greenhouse during six months. A total of 119 plant species were identified. Of these, 48 species were typical arable weeds and only one was red listed in Switzerland. The number of arable weeds per former field was lower at higher altitudes. Hence, the surveyed meadows have a small potential to promote threatened arable weeds if tilled again. Likely, some seeds were no longer viable because the fields were not tilled for a too long. If on newly established conservation fields no threatened species grow spontaneously after a few years, the reintroduction of desired plant species should be considered. The source of the seeds should preferably be a nearby species pool