Portail documentaire

Current state and drivers of arable plant diversity in conventionally managed farmland in northwest Germany / Alexander Wietzke in Diversity, 12 (12) (December 2020) 

Public Citation [article]  inDiversity > 12 (12) (December 2020) . - 469 Titre : Current state and drivers of arable plant diversity in conventionally managed farmland in northwest Germany Type de document : Imprimé Auteurs : Alexander Wietzke (1982-) ; Clara-Sophie van Waveren ; Erwin Bergmeier ; Stefan Meyer ; Christoph Leuschner (1956-) Année de publication : 2020 Article en page(s) : 469 Langues : Anglais (eng) Catégories : [Géographique] Allemagne [Thématique] Messicole Résumé : Agricultural intensification has led to dramatic diversity losses and impoverishment of the arable vegetation in much of Europe. We analyzed the status of farmland phytodiversity and its determinants in 2016 in northwest Germany by surveying 200 conventionally managed fields cultivated with seven crops. The study was combined with an analysis of edaphic (soil yield potential), agronomic (crop cover, fertilizer and herbicide use) and landscape factors (adjacent habitats). In total, we recorded 150 non-crop plant species, many of them nitrophilous generalist species, while species of conservation value were almost completely absent. According to a post-hoc pairwise comparison of the mixed model results, the cultivation of rapeseed positively influenced non-crop plant species richness as compared to winter cereals (wheat, barley, rye and triticale; data pooled), maize or potato. The presence of grassy strips and ditch margins adjacent to fields increased plant richness at field edges presumably through spillover effects. In the field interiors, median values of non-crop plant richness and cover were only 2 species and 0.5% cover across all crops, and at the field edges 11 species and 4% cover. Agricultural intensification has wiped out non-crop plant life nearly completely from conventionally managed farmland, except for a narrow, floristically impoverished field edge strip. Lien pérenne : DOI : 10.3390/d12120469 Wietzke, A., Waveren, C.S.v., Bergmeier, E., Meyer, S., Leuschner, C. 2020. Current state and drivers of arable plant diversity in conventionally managed farmland in northwest Germany. Diversity, 12(12): 469.

Documents numériques

Consultable Article (2020) URL

Dramatic losses of specialist arable plants in Central Germany since the 1950s/60s – a cross-regional analysis / Stefan Meyer in Diversity and Distributions, 19 (9) (September 2013) 

Public Citation [article]  inDiversity and Distributions > 19 (9) (September 2013) . - 1175-1187 Titre : Dramatic losses of specialist arable plants in Central Germany since the 1950s/60s – a cross-regional analysis Type de document : Électronique Auteurs : Stefan Meyer ; Karsten Wesche ; Benjamin Krause ; Christoph Leuschner (1956-) Année de publication : 2013 Article en page(s) : 1175-1187 Langues : Français (fre) Catégories : [Géographique] Allemagne [Thématique] Messicole Résumé : To assess the consequences of agricultural intensification since the 1950s for Central Europe's plant communities of arable plants. Location : Central Germany. We employed a semipermanent plot design to analyse changes in 392 field interiors for 10 study regions, including sandy, limestone and loamy sites between the 1950s/60s and 2009. The analysis revealed a reduction in the regional species pool during the 50-year period of 23% (from 301 to 233 vascular species) and dramatic losses in plot-level diversity (from medians of 24 to 7). Median cover of spontaneously growing arable plants decreased from 30% to 3%. Losses were disproportionally larger on limestone sites while sandy sites maintained a larger fraction of the original diversity. Archaeophytes, neophytes and most Poaceae (including some aggressive weeds) showed similarly strong losses as indigenous plants. This contradicts the assumption that grasses and neophytes are generally profiting from agricultural intensification. Crop diversity decreased from 25 crop plants present in the 1950s/60s to only 16 in 2009, while crop cover generally increased. Winter cereals, oilseed rape and maize are dominant today, while all other crop types showed strong declines. Vegetation change over time depended on soil substrate with once markedly different arable communities now showing more homogenized community structure. Increasing Ellenberg indicator values for nitrogen and pH point to N fertilization as a major driver of change. New conservation measures such as the establishment of field flora reserves and agri-environment schemes with less intensive land use are thus urgently needed especially on limestone substrates to bring an end to the decline of this functionally distinct and increasingly threatened component of the Central European flora. Lien pérenne : DOI : 10.1111/ddi.12102 Meyer, S., Wesche, K., Krause, B., Leuschner, C. 2013. Dramatic losses of specialist arable plants in Central Germany since the 1950s/60s – a cross-regional analysis. Diversity and Distributions, 19(9): 1175-1187.

Documents numériques

Consultable Article (2013) URL

Impoverishment of the arable flora of Central Germany during the past 50 years: a multiple-scale analysis / Stefan Meyer (2013) 

Public Citation Titre : Impoverishment of the arable flora of Central Germany during the past 50 years: a multiple-scale analysis Type de document : Électronique Auteurs : Stefan Meyer Editeur : Göttingen : Göttingen Centre for Biodiversity and Ecology Année de publication : 2013 Collection : Biodiversity and Ecology Series B num. 9 Importance : 175 p. Catégories : [Thématique] Messicole [Géographique] Allemagne Résumé : Since the first creation of arable land a crop-adapted flora and fauna has developed as a byproduct of low-intensity agriculture. Intensification and economic optimization of agricultural production during the last few decades have led to simplified agricultural landscapes and a decrease in spatial heterogeneity, resulting in a dramatic loss of species diversity and population decline of arable plants. In this context, numerous recent studies have pointed out that a diverse arable flora plays a key role in the functioning of agricultural systems, acting to maintain beneficial ecological functions (e.g. support of higher trophic levels or provision of ecosystem services). The aim of this thesis is to provide insights into the influence of agricultural intensification processes on shifts in arable vegetation from the continental to the population level for evaluating existing arable plant conservation schemes and proposing future strategies. Within the framework of this thesis, all observational studies were carried out in Central Germany. This study demonstrates a dramatic impoverishment of the arable vegetation on all major organisational levels. At the continental European scale, we found a positive relationship between national wheat yields and the numbers of rare, threatened or recently extinct arable plant species in each European country. It was found that for every extra tonne/hectare of wheat produced approximately ten more plant species become nationally threatened. Specialist species adapted to certain crops were among the most threatened. The results from this study showed that the increased use of agro-chemicals, especially in the EU Member States in Central and North-Western Europe, has selected against a larger group of arable species adapted to habitats with intermediate fertility. Moving to finer scale on the community level, this study clearly demonstrates that the European-wide intensification of arable habitat use has led to massive shifts in the arable plant community composition. In the 1950s/60s, most of the relevés could be easily assigned on association level, while the recent relevés could often only be classified at the level of higher syntaxa such as alliance, order, class or ‘fragmental’ floristicallyimpoverished communities. In this context, our analysis revealed a reduction of 23% in the number of species in the regional species pool during the 50-yr period, dramatic losses in plot-level diversity (median loss of 17 species per relevé) and decreasing population sizes of rare and diagnostic species. The results also indicate that vegetation changes depended on geological substrate, with sandy sites being less severely affected. Furthermore, the average cover of arable plants has dramatically decreased to a tenth of its original extent, while crop cover generally increased and crop diversity decreased. Archaeophytes, neophytes and most Poaceae (including some highly competitive weeds) showed large frequency losses similar to that of indigenous herbarceous plants, but only modest changes in their share of total arable plant cover. The observed increasing Ellenberg indicator values (EIV) for nitrogen and pH indicate that N-fertilisation may, in combination with increasing usage of herbicides and denser crop stands, act as a major driver of change in the arable vegetation. Consequently, the reported clear trend towards homogenization in community structure, where specialists and diagnostic species have disappeared and generalists increased is reflecting the growing uniformity in crop management schemes and soil fertility levels in recent time. The reported decreasing population sizes, especially in rare species with small populations (in this case Adonis aestivalis L. and Consolida regalis S.F. GRAY), are shown to affect their genetic diversity. In this context, also landscape complexity plays an important role because genetic structure varies among species and populations. However, contrary to expectation, within-population diversity levels of the species were significantly higher in populations located in monotonous landscapes than in populations of structurally diverse landscapes. Populations from diverse landscapes differed more significantly from each other than those from monotonous landscapes. Furthermore, we observed high within-population diversity for the outcrossing C. regalis, but low within-population diversity for the self-pollinating A. aestivalis. However, neither A. aestivalis nor C. regalis showed a significant isolation-by-distance regardless of landscape structure. In conclusion, the present study shows that arable plant communities are under dramatic threat, affecting all major organisational levels from the European scale to the population level. The rapid shifts in the highly dynamic agro-ecosystems within the last few decades have strongly influenced community structure, plant diversity, population sizes and genetic variation. To achieve the defined target of increasing the population size of the majority of species in agricultural ecosystems by 2015, new, effective and innovative schemes and programs are urgently required. Especially the design of the Common agricultural policy (CAP) after 2013 will be of major importance for the task to halt the loss of arable plant biodiversity in the agricultural landscape. Lien pérenne : DOI : 10.3249/webdoc-3898 Meyer, S. 2013. Impoverishment of the arable flora of Central Germany during the past 50 years: a multiple-scale analysis. Göttingen Centre for Biodiversity and Ecology, Göttingen. 175 pp.

Documents numériques

Consultable Thèse (2013) URL

A new conservation strategy for arable plant vegetation in Germany – the project / Stefan Meyer in Plant Breeding and Seed Science, 61 (2010) 

Public Citation [article]  inPlant Breeding and Seed Science > 61 (2010) . - 25-34 Titre : A new conservation strategy for arable plant vegetation in Germany – the project Type de document : Imprimé Auteurs : Stefan Meyer ; Karsten Wesche ; Christoph Leuschner (1956-) ; Thomas van Elsen (1959-) ; Jürgen Metzner (1941-) Année de publication : 2010 Article en page(s) : 25-34 Catégories : [Thématique] Messicole [Thématique] Biodiversité [Thématique] Conservation et gestion des espèces [Géographique] Allemagne Résumé : t is prudent to conserve communities which are as species-rich as possible. This is the only means of ensuring that species diversity but also gene diversity is high enough to allow for the necessary adaptations to changed environmental conditions. Arable plant communities are a special case here because losses in the last 5 decades have been particularly severe. Numerous studies from Central Europe reported dramatic declines of the segetal flora.In most of the federal states of Germany, successful measures for protecting the segetal flora, such as the establishment of field flora reserves and field margin strip programmes have often unfortunately come to a halt due to changes in funding, lack of regional support or high levels of bureaucracy. The new project "100 fields for biodiversity", which has been funded by the Deutsche Bundesstiftung Umwelt (DBU) since 2007, aims to establish a network of protected areas for the preservation of endangered segetal species in Germany. Management aimed at preserving and fostering arable wild plants is to be guaranteed in the long term on at least 100 particularly suitable arable sites... Lien pérenne : DOI : 10.2478/v10129-010-0009-3 Meyer, S., Wesche, K., Leuschner, C., Elsen, T.v., Metzner, J. 2010. A new conservation strategy for arable plant vegetation in Germany – the project. Plant Breeding and Seed Science, 61: 25-34.

Documents numériques

Consultable Article (2010) URL

The impact of agricultural intensification and land-use change on the European arable flora / Jonathan Storkey in Proceedings of the Royal Society. Biological Sciences, 279 (April 2012) 

Public Citation [article]  inProceedings of the Royal Society. Biological Sciences > 279 (April 2012) . - 1421-1429 Titre : The impact of agricultural intensification and land-use change on the European arable flora Type de document : Imprimé Auteurs : Jonathan Storkey ; Stefan Meyer ; Kate Still ; Christoph Leuschner (1956-) Année de publication : 2012 Article en page(s) : 1421-1429 Langues : Anglais (eng) Catégories : [Géographique] Europe [Thématique] Incidence des activités agricoles [Thématique] Messicole Résumé : The impact of crop management and agricultural land use on the threat status of plants adapted to arable habitats was analysed using data from Red Lists of vascular plants assessed by national experts from 29 European countries. There was a positive relationship between national wheat yields and the numbers of rare, threatened or recently extinct arable plant species in each country. Variance in the relative proportions of species in different threat categories was significantly explained using a combination of fertilizer and herbicide use, with a greater percentage of the variance partitioned to fertilizers. Specialist species adapted to individual crops, such as flax, are among the most threatened. These species have declined across Europe in response to a reduction in the area grown for the crops on which they rely. The increased use of agro-chemicals, especially in central and northwestern Europe, has selected against a larger group of species adapted to habitats with intermediate fertility. There is an urgent need to implement successful conservation strategies to arrest the decline of this functionally distinct and increasingly threatened component of the European flora. Lien pérenne : DOI : 10.1098/rspb.2011.1686 Storkey, J., Meyer, S., Still, K., Leuschner, C. 2012. The impact of agricultural intensification and land-use change on the European arable flora. Proceedings of the Royal Society. Biological Sciences, 279: 1421-1429.

Documents numériques

Consultable Article (2012) URL