• Energy Research
• 2. Zero hunger close
• EU close
• BE close
• Wageningen Staff Publications close

Abstract An assessment of the human impact on the global water cycle requires estimating the volume of water withdrawn for irrigated agriculture. A key parameter in this calculation is the irrigation efficiency, which corrects for the fraction of water lost between irrigation withdrawals and the crop due to management, distribution or conveyance losses. Here we show that the irrigation efficiency used in global irrigation models is flawed for it overlooks key ambiguities in partial efficiencies, irrigation technologies, the definition of ‘large-scale’ irrigated areas or managerial factors. Once accounted for, these uncertainties can make irrigation withdrawal estimates fluctuate by more than one order of magnitude at the country level. Such variability is larger and leads to more extreme values than that caused by the uncertainties related with climate change. Our results highlight the need to embrace deep uncertainties in irrigation efficiency to prevent the design of shortsighted policies at the river basin-water-agricultural interface.

AbstractConversion of semi-natural habitats, such as field margins, fallows, hedgerows, grassland, woodlots and forests, to agricultural land could increase agricultural production and help meet rising global food demand. Yet, the extent to which such habitat loss would impact biodiversity and wild species is unknown. Here we survey species richness for four taxa (vascular plants, earthworms, spiders, wild bees) and agricultural yield across a range of arable, grassland, mixed, horticulture, permanent crop, for organic and non-organic agricultural land on 169 farms across 10 European regions. We find that semi-natural habitats currently constitute 23% of land area with 49% of species unique to these habitats. We estimate that conversion of semi-natural land that achieves a 10% increase in agricultural production will have the greatest impact on biodiversity in arable systems and the least impact in grassland systems, with organic practices having better species retention than non-organic practices. Our findings will help inform sustainable agricultural development.

Abstract A central challenge of today's ecological research is predicting how ecosystems will develop under future global change. Accurate predictions are complicated by (a) simultaneous effects of different drivers, such as climate change, nitrogen deposition and management changes; and (b) legacy effects from previous land use. We tested whether herb layer biodiversity (i.e. richness, Shannon diversity and evenness) and functional (i.e. herb cover, specific leaf area [SLA] and plant height) responses to environmental change drivers depended on land‐use history. We used resurvey data from 192 plots across nineteen European temperate forest regions, with large spatial variability in environmental change factors. We tested for interactions between land‐use history, distinguishing ancient and recent (i.e. post‐agricultural) forests and four drivers: temperature, nitrogen deposition, and aridity at the regional scale and light dynamics at the plot‐scale. Land‐use history significantly modulated global change effects on the functional signature of the herb layer (i.e. cover, SLA and plant height). Light availability was the main environmental driver of change interacting with land‐use history. We found greater herb cover and plant height decreases and SLA increases with decreasing light availability in ancient than in recent forests. Furthermore, we found greater decreases in herb cover with increased nitrogen deposition in ancient forests, whereas warming had the strongest decreasing effect on the herb cover in recent forests. Interactive effects between land‐use history and global change on biodiversity were not found, but species evenness increased more in ancient than in recent forests. Synthesis. Our results demonstrate that land‐use history should not be overlooked when predicting forest herb layer responses to global change. Moreover, we found that herb layer composition in semi‐natural deciduous forests is mainly controlled by local canopy characteristics, regulating light levels at the forest floor, and much less by environmental changes at the regional scale (here: warming, nitrogen deposition and aridity). The observed disconnect between biodiversity and functional herb layer responses to environmental changes demonstrates the importance of assessing both types of responses to increase our understanding of the possible impact of global change on the herb layer.

Europe is, after Asia, the second largest producer of wheat in the world, and provides the largest share of barley. Wheat (and to a similar extent, barley) production in Europe increased by more than 6-fold during the 20th century. During the first half of the 20th century, this was driven by expanding the harvested area. This was followed, from the mid-20th century, by a massive increase in productivity that in many regions has stalled since 2000. However, it remains unclear what role climatic factors have played in these changes. Understanding the net impact of climatic trends over the past century would also aid in our understanding of the potential impact of future climate changes and in assessments of the potential for adaptation across Europe. In this study, we compiled information from several sources on winter wheat and spring barley yields and climatological data from 12 countries/regions covering the period from 1901-2012. The studied area includes the majority of climatic regions in which wheat and barley are grown (from central Italy to Finland). We hypothesized that changes in climatic conditions have led to measurable shifts in climate-yield relationships over the past 112 yr, and that presently grown wheat and barley show a more pronounced response to adverse weather conditions compared to crops from the early 20th century. The results confirm that climate-yield relationships have changed significantly over the period studied, and that in some regions, different predictors have had a greater effect on yields in recent times (between 1991 and 2012) than in previous decades. It is likely that changes in the climate-yield relationship at the local level might be more pronounced than those across the relatively large regions used in this study, as the latter represents aggregations of yields from various agroclimatic and pedoclimatic conditions that may show opposing trends.

AbstractCentral Asian grasslands are extensively used for pastoral livestock grazing. This traditional land use is nowadays characterized by intensifying grasslands into more productive pastures. This change affects biodiversity and diminishes grasslands’ ecological role. Biodiversity impacts are probably also exacerbated by climate change. These changes in biodiversity are poorly studied in Central Asia. Here, we estimated potential biodiversity changes in the Central Asian grasslands using the latest shared socio-economic pathways and the representative concentration pathways (i.e., SSP-RCP scenario framework). We selected scenarios with contrasting socio-economic and climate conditions (i.e., SSP1-RCP4.5, SSP3-RCP8.5, SSP4-RCP4.5, and SSP5-RCP8.5) and further detailed the land-use scenarios for the region using stakeholders’ input. We indicated future biodiversity by the mean species abundance indicator. The contrasting scenario combinations showed that grasslands’ biodiversity will decline under each scenario. The strongest impact on biodiversity is expected in SSP5-RCP8.5, where half of the grasslands are likely to lose most of their local originally occurring species by 2100. The lowest impact is expected in SSP4-RCP4.5. Our study stresses the potential vulnerability of this region to increasing land-use intensity and climate change. These impact projections can help regional decision makers to develop and implement better biodiversity-conservation and sustainable management policies for these grasslands.

European landscapes are facing a deep crisis. As a consequence of globalization and the economical change associated with it, traditional functions like production agriculture are becoming less important. After the self-evident but inspired landscapes of numerous generations of peasants, monks and landlords, landscape has now largely become a nameless by-product of the global economy. This paper shows that the key to developing new living landscapes lies in a participatory process of landscape development with respect for their inherent values. Today, even in traditionally small-scale farming systems like organic farming, diverse and sustainable landscapes only develop if they are consciously wanted and when landscape development is integrated into the objectives of farming. The work that is needed to achieve such landscapes we call `landscape work¿. This paper describes a phenomenological approach to identifying landscape values and finding new inspiration for landscape management. It gives examples of the application of this approach in organic farming in Germany. It is concluded that a living, sustainable landscape combines the functional effects of producing economic and social benefits with the intertwined effects of providing identity and inspiration for getting actively involved in it, in accordance with its dynamic character. Living landscapes will enhance the well being, also of the predominantly urban European population. In other words: landscape work s.