Abstract. Ozone (O3) pollution reduces wheat yields as well as the protein and micronutrient yield of the crop. O3 concentrations are particularly high in India and are set to increase, threatening wheat yields and quality in a country already facing challenges to food security. This study aims to improve the existing DO3SE-CropN model to simulate the effects of O3 on Indian wheat quality by incorporating antioxidant processes to simulate protein and the concentrations of nutritionally relevant amino acids. As a result, the improved model can now capture the decrease in protein concentration that occurs in Indian wheat exposed to elevated O3. The structure of the modelling framework is transferrable to other abiotic stressors and easily integrable into other crop models, provided they simulate leaf and stem nitrogen (N), demonstrating the flexibility and usefulness of the framework developed in this study. Further, the modelling results can be used to simulate the dietary indispensable amino acid score (DIAAS), the metric for measuring protein quality recommended by the Food and Agriculture Organization (FAO) of the United Nations, setting up a foundation for nutrition-based risk assessments of O3 effects on crops. The resulting model was able to capture grain protein, lysine and methionine concentrations reasonably well. As a proportion of dry matter, the simulated percentages ranged from 0.26 % to 0.38 % for lysine and from 0.13 % to 0.22 % for methionine, while the observed values were 0.16 % to 0.38 % and 0.14 % to 0.22 %, respectively. For grain and leaf protein simulations, the interdependence between parameters reduced the accuracy of their respective relative protein loss under O3 exposure. Additionally, the decrease in lysine and methionine concentrations under O3 exposure was underestimated by ∼ 10 percentage points for methionine for both cultivars and by 37 and 19 percentage points for lysine for HUW234 and HD3118, respectively. This underestimation occurs despite simulations of relative yield loss being fairly accurate (average deviation of 2.5 percentage points excluding outliers). To provide a further mechanistic understanding of O3 effects on wheat grain quality, future experiments should measure N and protein concentrations in leaves and stems, along with the proportion of N associated with antioxidants, which will aid in informing future model development. Additionally, exploring how grain protein relates to amino acid concentrations under O3 will enhance the model's accuracy in predicting protein quality and provide more reliable estimates of the influence of O3 on wheat quality. This study builds on the work of Cook et al. (2024) and supports the second phase of the Tropospheric Ozone Assessment Report (TOAR) by investigating the impacts of tropospheric O3 on Indian wheat and the potential of this to exacerbate existing malnutrition in India.
On Thursday 13th July 2017, the University of Leeds hosted a major one-day national conference entitled ‘The Future of Public Parks’ at The British Academy in London. The conference was generously sponsored by the Leeds Social Sciences Institute and idverde, with support from The Parks Alliance, Historic England and Groundwork. Some 79 delegates participated in a lively and engaging event which drew together innovative thinking and learning from policy, practice and research on ways to maximise the value of parks as public assets in the twenty-first century, and to consider challenges that threaten the sustainability of public parks in the future.
The event brought together academics from diverse disciplines, funding bodies, policy-makers and practitioners from the across the public, voluntary and private sectors. At a time when the future of public parks is both in the balance and in the national spotlight, the presenters and delegates explored important issues and challenges that inform diverse models of park management whether local authorities, trusts, charities or private sector. These included questions about health and well-being, social and educational use, community involvement and strategies for generating income. The conference provided a timely opportunity to foster a research-informed, policy and practice-orientated dialogue about park futures and offered a platform for advancing public debate in light of the findings and recommendations of the Communities and Local Government Select Committee Inquiry. Importantly, it provided a unique opportunity for multi-disciplinary, inter-professional and cross-sectoral debate that enabled delegates to explore common questions, mutual strategies and shared interest in promoting the social role and value of public parks.
Public parks are long-standing and familiar features of the urban environment. For many people, visiting parks is an integral part of everyday life in the contemporary city. Yet parks in the UK are at a possible ‘tipping point’, prompting important concerns about their sustainability. Parks face essential challenges over funding and management, as well as questions of unequal access and competing demands on use. This study of public parks in the city of Leeds focused on how they have changed through time, how they are used today, and what their future prospects might be.
Abstract. Ozone (O3) air pollution is well known to adversely affect both the grain and protein yield of wheat, an important staple crop. This study aims to identify and model the key plant processes influencing the effect of O3 on wheat protein. We modified the DO3SE-Crop model to incorporate nitrogen (N) processes, and parameterised the O3 effect on stem, leaf and grain N using O3 fumigation datasets spanning 3 years and 4 O3 treatments. Our results show the new model captures the O3 effect on grain N concentrations, and anthesis leaf and stem concentration, well. However, the O3 effect on harvest leaf and stem N is exaggerated. Further, a sensitivity analysis revealed that, irrespective of O3 treatment, accelerated senescence onset was the primary plant process affecting grain N. This modelling study therefore demonstrates the capability of the DO3SE-CropN model to simulate processes by which O3 affects N content, and thereby determines that senescence onset is the main driver of O3 reductions in grain protein yield. The implication of the sensitivity analysis is that breeders should focus their efforts on stay-green cultivars that do not experience a protein penalty when developing O3 tolerant lines, to maintain both wheat yield and nutritional quality under O3 exposure.
Abstract. A substantial body of empirical evidence exists to suggest that elevated O3 levels are causing significant impacts on wheat yields at sites representative of highly productive arable regions of China. Here, we extend the DO3SE model (designed to estimate total- and stomatal- O3 deposition for risk assessment) to incorporate a coupled Anet-gsto model to estimate O3 uptake, an O3 damage module (that impacts instantaneous Anet and the timing and rate of senescence), and a crop phenology, carbon allocation and growth model based on the JULES-Crop model. The model structure allows scaling from the leaf to the canopy to allow for multiple leaf populations and canopy layers. The DO3SE-crop model is calibrated and parametrised using O3 fumigation data from Xiaoji, China for the year 2008 and for an O3 tolerant and sensitive cultivar. The calibrated model can simulate key physiological variables, crop development, and yield with a good level of accuracy compared to experimental observations. DO3SE-crop accurately depicted the difference in yield reductions under ambient and elevated O3 treatments for wheat cultivars Y16 (tolerant) and Y2 (sensitive) with regressions of modelled and observed absolute yields resulting in an R² of 0.99 and an RMSE of 9.27 g/m². Further, when evaluated for 2007 and 2009 for all cultivars, the DO3SE-crop model simulated O3-induced yield losses of 4–25 % compared to observed yield losses of 12–34 %, with an R² of 0.73 and an RMSE of 58.41 g/m². Additionally, our results indicate that the variance in yield reduction is primarily attributed to the premature decrease in carbon assimilation to the grains under elevated O3 exposure. This is linked to accelerated leaf senescence, which brings leaf senescence forward by 7–9 days under elevated O3 treatments.
The western Indian state of Rajasthan experiences significantly high surface levels of ozone (O3) during wheat cultivation season causing wheat yield losses. We estimated the losses in wheat production in selected districts of Rajasthan using concentration-based O3 exposure metrics-observed hourly O3 concentrations, AOT40 and M7, and the flux-based phytotoxic O3 dose (POD3) during 2018-2022. During this period, the district-level yield losses ranged from 0.46% to 5.5% (POD3), 0.92% to 19.34% (M7), and 0.91% to 28% (AOT40). These yield losses translated to wheat crop production losses (CPL) of 9.45×104 tonnes (POD3), 12.75× 104 tonnes (M7), and 18.15× 104 tonnes (AOT40) for the selected study areas. The corresponding economic cost losses (ECL) were USD 0.024 billion (POD3), USD 0.032 billion USD (M7), and USD 0.044 billion (AOT40). Our findings of higher yield losses observed in AOT40, followed by M7, and POD3, highlight the tendency of concentration-based metrics to estimate higher crop losses due to O3 on wheat production compared to the biologically more meaningful flux-based estimates. India has a critical gap in research on flux-based responses in wheat, yet our crop production loss estimates based on existing research reaffirm the significant threat that current and projected O3 levels pose to the country's food security through reduced crop yields. This study suggests that using the relationship between O3 flux and its effects on wheat could be a valuable tool. In India, this approach could assess and predict O3 risks to wheat varieties and be incorporated into crop models to forecast climate change impacts on crop productivity.
Abstract While the Victorian ideal of the public park is well understood, we know less of how local governors sought to realize this ideal in practice. This article is concerned with park-making as a process – contingent, unstable, open – rather than with parks as outcomes – determined, settled, closed. It details how local governors bounded, designed and regulated park spaces to differentiate them as ‘spaces apart’ within the city, and how this programme of spatial governance was obstructed, frustrated and diverted by political, environmental and social forces. The article also uses this historical analysis to provide a new perspective on the future prospects of urban parks today.
Ground-level ozone (O3) pollution occurs across many important agricultural regions in Europe, North America, and Asia, negatively impacting O3-sensitive crops such as wheat. Risk assessment methods to quantify the magnitude and spatial extent of O3 pollution have often used dose-response relationships. In Europe, the dose metrics used in these relationships have evolved from concentration- to flux-based metrics since stomatal O3 flux has been found to correlate better with yield losses. Estimates of stomatal conductance (gsto) have to date used an empirical multiplicative model. However, other more mechanistic approaches are available, namely the coupled photosynthetic-stomatal conductance (Anetgsto) model. This study used a European O3 OTC and solardome fumigation experimental dataset (comprising 6 cultivars, 4 countries and 14 years) to develop a new flux-based dose-response relationship for wheat yield using the mechanistic Anetgsto model (Anetgstomech). The Anetgstomech model marginally improved the regression of the dose-response relationship (R2 = 0.74) when compared to the flux-response models derived from empirical gsto models. In addition, the Anetgstomech model was somewhat better at predicting the effect of high O3 concentrations on diurnal and seasonal profiles of gsto and Anet. It was also better able to simulate changes of up to 7 and 12 days, respectively, in the start (SOS) and end (EOS) of senescence, an important determinant of yield loss, over a range of O3 treatments. We conclude that Anetgstomech model can be used to derive robust flux-response relationships.
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