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.

Aim To assess the consequences of agricultural intensification since the 1950s for Central Europe's plant communities of arable plants.Location Central Germany.Methods 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. ResultsThe 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.Main conclusions 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.

Land degradation-defined by the Millennium Ecosystem Assessment report as the long-term loss of ecosystems services-is a global problem, negatively affecting the livelihoods and food security of billions of people. Intensifying efforts, mobilizing more investments and strengthening the policy commitment for addressing land degradation at the global level needs to be supported by a careful evaluation of the costs and benefits of action versus costs of inaction against land degradation. Consistent with the definition of land degradation, we adopt the Total Economic Value (TEV) approach to determine the costs of land degradation and use remote sensing data and global statistical databases in our analysis. The results show that the annual costs of land degradation due to land use and land cover change (LUCC) are about US$231 billion per year or about 0.41 % of the global GDP of US$56.49 trillion in 2007. Contrary to past global land degradation assessment studies, land degradation is severe in both tropical and temperate countries. However, the losses from LUCC are especially high in Sub-Saharan Africa, which accounts for 26 % of the total global costs of land degradation due to LUCC. However, the local tangible losses (mainly provisioning services) account only for 46 % of the total cost of land degradation and the rest of the cost is due to the losses of ecosystem services (ES) accruable largely to beneficiaries other than the local land users. These external ES losses include carbon sequestration, biodiversity, genetic information and cultural services. This implies that the global community bears the largest cost of land degradation, which suggests that efforts to address land degradation should be done bearing in mind that the global community, as a whole, incurs larger losses than the local communities experiencing land degradation. The cost of soil fertility mining due to using land degrading management practices on maize, rice and wheat is estimated to be about US$15 billion per year or 0.07 % of the global GDP. Though these results are based on a crop simulation approach that underestimates the impact of land degradation and covers only three crops, they reveal the high cost of land degradation for the production of the major food crops of the world. Our simulations also show that returns to investment in action against land degradation are twice larger than the cost of inaction in the first six years alone. Moreover, when one takes a 30-year planning horizon, the returns are five dollars per each dollar invested in action against land degradation. The opportunity cost accounts for the largest share of the cost of action against land degradation. This explains why land users, often basing their decisions in very short-time horizons, could degrade their lands even when they are aware of bigger longer-term losses that are incurred in the process.

Abstract. 1. As mature tropical forests disappear, secondary forests with their potential to conserve mature tropical forest species are increasingly of interest in a conservation context.2. We investigated the recovery of litter inhabiting beetle diversity and composition during natural forest regeneration in the coastal submontane forest of Southern Brazil, using chronosequences on two different soil types: cambisol and gleysol. Secondary forests, ranging in ages from 5 to 50 years, as well as old-growth forests were studied. Beetles were sifted from leaf litter and extracted using the Winkler technique.3. Young secondary forests had a very low species density and a significantly different and heterogeneous species composition compared to old-growth forests. During forest regeneration, species density greatly increased and the species composition of older secondary forests was similar to that of old-growth forests. The recovery pattern of species density and composition differed between soil types; nonetheless, they showed the same tendencies generally. Thus, mature secondary forests of about 35-50 years can be assumed to contribute substantially to the maintenance of forest beetle species.4. Litter quantity was not only significantly correlated with species density; but, even reflected the density pattern of both soil types. Thus, litter quantity is an important factor for maintaining or recovering high beetle densities. The composition of beetle assemblages was strongly affected by soil type. Thus, soil type should be considered in regional biodiversity monitoring and conservation actions.

Question: The intensification of crop cultivation in much of Europe since the mid-20th century has greatly increased crop yields but caused dramatic biodiversity losses in arable fields. We investigated the extent of these losses at the level of plant community types.Location: Ten areas in central Germany with different soil/climate conditions and various arable plant communities. Methods:We compiled historical surveys of arable fields in the 1950s/early 1960s before the onset of pervasive agricultural industrialization, and in 2009 revisited 392 arable fields. Historical and recent data were compared with supervised manual classification, detrended correspondence analysis (DCA) and ANOVA.Results: Ten out of 16 plant communities at association rank observed in fields in the 1950s/1960s were not recorded again. The proportion of relev es assignable at association level decreased from 75% to 5%, while the proportion of relev es assignable only at higher syntaxon level or not assignable at all had increased from 2% to 75%. The impoverishment of vegetation was slightly less pronounced at field margins, where around one quarter of the recent relev es could be assigned to associations. Present arable plant communities in the region are species-poor and consist chiefly of common, often herbicide-tolerant, generalist species, with no clear preference for cereal vs root crops, autumn-vs springsown crops or base-rich vs base-poor soils.Conclusion: Our new approach using phytosociological syntaxa and a semipermanent plot design enabled us to quantify biodiversity losses at the community type level. The currently used set of phytosociological associations is inadequate to represent present-day arable plant assemblages. The concept of residual plant communities provides a useful methodological supplement.