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Abstract Natural flood management (NFM) is widely promoted for managing flood risks but the effectiveness of different types of NFM schemes at medium (100–1000 km2) and large scales (>1000 km2) remains widely unknown. This study demonstrates the importance of fully understanding the impact of model structure, calibration and uncertainty techniques on the results before the NFM assessment is undertaken. Land‐based NFM assessment is undertaken in two medium‐scale lowland catchments within the Thames River basin (UK) with a modelling approach that uses the Soil and Water Assessment Tool (SWAT) model within an uncertainty framework. The model performed poorly in groundwater‐dominated areas (P‐factor 0.6). The model performed better in areas dominated by surface and interflow processes (P‐factor >0.5 and R‐factor

Abstract In the United Kingdom, woodland planting and soil and crop management are being promoted as approaches to tackling flooding. Although evidence is limited, it is thought tree planting and regenerative agriculture practices such as crop–herbal ley pasture rotations increase infiltration, soil water storage and evapotranspiration, potentially reducing flooding. A process‐based soil–water–vegetation model was coupled with a semi‐distributed groundwater model to explore the impact of these interventions on peak and low flows in a large, groundwater‐dominated catchment. Land use change and management were found to have limited potential to reduce flooding in this setting. Herbal ley–crop rotations produced a 2 years, and levels of woodland planting judged to be the realistic maximum produced reductions of 0.2%–2.6%, depending on tree species. Broadscale spruce planting was the only scenario to produce significant reductions in peak flow (16.0%–24.7% at return periods 1–15 years); however, the level of spruce planting required to achieve these reductions was estimated to reduce Q95 flow by ~39%, which would likely have negative implications for water security and ecological river flows. The impact of land‐based natural flood management interventions for flood prevention in large, permeable catchments should not be overstated.

The present work aimed to investigate the potential sources of water for plants in an area of evergreen forest located in western Amazonia (Rebio Jaru). We used a natural abundance of water isotopes—δ2H and δ18O—to trace the main source of water to plants at the beginning of the dry period (May 2016) and at the end of the dry period/transition to the wet period (October 2016) following a severe El Niño drought (ENSO 2015/16). Soil samples were collected in a soil profile up to 4 m depth. Plant samples from 18 trees (14 species) were collected in May and in October 2016. Rainwater and river water samples were collected between September 2015 and February 2017. We found that, at the end of the dry period/transition to the wet period (i.e., October 2016), the average plant xylem signal was more enriched (δ2H: −20.0 ± 8.1‰; δ18O: −1.13 ± 1.88‰) than in May 2016 (δ2H: −36.7 ± 5.6‰; δ18O: −3.50 ± 1.30‰), the onset of the dry period. The averaged isotopic soil signal in May 2016 (δ2H: −35.4 ± 5.90‰; δ18O: −5.19 ± 0.70‰) is slightly more depleted than in October (δ2H: −27.6 ± 13.8‰; δ18O: −4.35 ± 1.73‰) and, in general, more depleted than the xylem signal. In the dual isotope space, the xylem signal at the beginning of the dry period follows the rainfall signal of the wet period, while the xylem signal at the end of the dry period/transition to the wet period follows the signal of the dry season rainfall, suggesting that plants mostly transpire recent rainwater. Contrary to what was expected, we did not find evidence in the xylem signal of the water stored in the soil pores, which suggests that to meet to the water demands of the dry period, plants do not use the water from past periods stored in the soil layers.

Over the last 20 years, there has been a surge of interest in the use of reflectance data collected using satellites and aerial vehicles to monitor vegetation diversity. One methodological option to monitor these systems involves developing empirical relationships between spectral heterogeneity in space (spectral variation) and plant or habitat diversity. This approach is commonly termed the ‘Spectral Variation Hypothesis’. Although increasingly used, it is controversial and can be unreliable in some contexts. Here, we review the literature and apply three-level meta-analytical models to assess the test results of the hypothesis across studies using several moderating variables relating to the botanical and spectral sampling strategies and the types of sites evaluated. We focus on the literature relating to grasslands, which are less well studied compared to forests and are likely to require separate treatments due to their dynamic phenology and the taxonomic complexity of their canopies on a small scale. Across studies, the results suggest an overall positive relationship between spectral variation and species diversity (mean correlation coefficient = 0.36). However, high levels of both within-study and between-study heterogeneity were found. Whether data was collected at the leaf or canopy level had the most impact on the mean effect size, with leaf-level studies displaying a stronger relationship compared to canopy-level studies. We highlight the challenges facing the synthesis of these kinds of experiments, the lack of studies carried out in arid or tropical systems and the need for scalable, multitemporal assessments to resolve the controversy in this field.

Abstract Modeling of the land surface water‐, energy‐, and carbon balance provides insight into the behavior of the Earth System, under current and future conditions. Currently, there exists a substantial variability between model outputs, for a range of model types, whereby differences between model input parameters could be an important reason. For large‐scale land surface, hydrological, and crop models, soil hydraulic properties (SHP) are required as inputs, which are estimated from pedotransfer functions (PTFs). To analyze the functional sensitivity of widely used PTFs, the water fluxes for different scenarios using HYDRUS‐1D were simulated and predictions compared. The results showed that using different PTFs causes substantial variability in predicted fluxes. In addition, an in‐depth analysis of the soil SHPs and derived soil characteristics was performed to analyze why the SHPs estimated from the different PTFs cause the model to behave differently. The results obtained provide guidelines for the selection of PTFs in large scale models. The model performance in terms of numerical stability, time‐integrated behavior of cumulative fluxes, as well as instantaneous fluxes was evaluated, in order to compare the suitability of the PTFs. Based on this, the Rosetta, Wösten, and Tóth PTF seem to be the most robust PTFs for the Mualem van Genuchten SHPs and the PTF of Cosby for the Brooks Corey functions. Based on our findings, we strongly recommend to harmonize the PTFs used in model inter‐comparison studies to avoid artifacts originating from the choice of PTF rather from different model structures.

Hyperspectral leaf-level reflectance data may enable the creation of taxonomic inventories and diversity assessments of grasslands, but little is known about the stability of species-specific spectral classes and discrimination models over the course of a growing season. Here, we present a cross-seasonal dataset of seventeen species that are common to a temperate, dry and nutrient-poor calcareous grassland, which spans thirteen sampling dates, a week apart, during the spring and summer months. By using a classification model that incorporated waveband selection (a sparse partial least squares discriminant analysis), most species could be classified, irrespective of the sampling date. However, between 42 and 95% of the available spectral information was required to obtain these results, depending on the date and model run. Feature selection was consistent across time for 70 out of 720 wavebands and reflectance around 1410 nm, representing water features, contributed the most to the discrimination. Model transferability was higher between neighbouring sampling dates and improved after the “green-up” period. Some species were consistently easy to classify, irrespective of time point, when using up to six latent variables, which represented about 99% of the total spectral variance, whereas other species required many latent variables, which represented very small spectral differences. We concluded that it did seem possible to create reliable taxonomic inventories for combinations of certain grassland species, irrespective of sampling date, and that the reason for this could lie in their distinctive morphological and/or biochemical leaf traits. Model transferability, however, was limited across dates and cross-seasonal sampling that captures leaf development would probably be necessary to create a predictive framework for the taxonomic monitoring of grasslands. In addition, most variance in the leaf reflectance within this system was driven by a subset of species and this finding implies challenges for the application of spectral variance in the estimation of biodiversity.

Study region: Burabay National Nature Park (BNNP) of North Kazakhstan is located between humid boreal forests and an arid steppe of Central Asia. Study focus: The stable hydrogen and oxygen isotope analyses of precipitation, stream, lake and ground waters were used for water budget calculations of the BNNP endorheic lake system to assess the impact of increasing aridity on lakes in this most continental part of the Earth. New hydrological insights for the region: The stable isotope results confirmed two different types of lakes in BNNP: Burabay and Shortandy Lakes are more similar to higher latitude lakes (e.g. South Siberia), while Kishi and Ulken Shabakty Lakes are more comparable to the steppe lakes of Central Asia. The slopes of evaporation lines for this region, obtained by regression analysis of lake water samples, ranged from 4.57 (steppe lakes) to 6.21 (forest lakes). The evaporation over inflow ratios (0.34 Burabay, 0.69 Ulken Shabakty, and 0.53 Shortandy) are in good agreement with catchment water budget calculations reflecting different groundwater inputs and water retention times. The recent water level rise in the Ulken Shabakty Lake terminal basin was observed for the first time in a decade. This increase can be explained by the ‘fill and spill’ hypothesis and suggest that a single unusually wet year may significantly replenish water resources despite long-term increasing aridity of the region. Keywords: Endorheic lake, Evaporation, Fill and spill, Water balance, Stable isotopes, Groundwater

The accurate and timely assessment of pasture quantity and quality (i.e., nutritive characteristics) is vital for effective pasture management. Remotely sensed data can be used to predict pasture quantity and quality. This study investigated the ability of Sentinel-2 multispectral bands, convolved from proximal hyperspectral data, in predicting various pasture quality and quantity parameters. Field data (quantitative and spectral) were gathered for experimental plots representing four pasture types—perennial ryegrass monoculture and three mixtures of swards representing increasing species diversity. Spectral reflectance data at the canopy level were used to generate Sentinel-2 bands and calculate normalised difference indices with each possible band pair. The suitability of these indices for prediction of pasture parameters was assessed. Pasture quantity parameters (biomass and Leaf Area Index) had a stronger influence on overall reflectance than the quality parameters. Indices involving the 1610 nm band were optimal for acid detergent fibre, crude protein, organic matter and water-soluble carbohydrate concentration, while being less affected by biomass or LAI. The study emphasises the importance of accounting for the quantity parameters in the spectral data-based models for pasture quality predictions. These explorative findings inform the development of future pasture quantity and quality models, particularly focusing on diverse swards.

Infiltration in soils is a key process that partitions precipitation at the land surface into surface runoff and water that enters the soil profile. We reviewed the basic principles of water infiltration in soils and we analyzed approaches commonly used in land surface models (LSMs) to quantify infiltration as well as its numerical implementation and sensitivity to model parameters. We reviewed methods to upscale infiltration from the point to the field, hillslope, and grid cell scales of LSMs. Despite the progress that has been made, upscaling of local-scale infiltration processes to the grid scale used in LSMs is still far from being treated rigorously. We still lack a consistent theoretical framework to predict effective fluxes and parameters that control infiltration in LSMs. Our analysis shows that there is a large variety of approaches used to estimate soil hydraulic properties. Novel, highly resolved soil information at higher resolutions than the grid scale of LSMs may help in better quantifying subgrid variability of key infiltration parameters. Currently, only a few LSMs consider the impact of soil structure on soil hydraulic properties. Finally, we identified several processes not yet considered in LSMs that are known to strongly influence infiltration. Especially, the impact of soil structure on infiltration requires further research. To tackle these challenges and integrate current knowledge on soil processes affecting infiltration processes into LSMs, we advocate a stronger exchange and scientific interaction between the soil and the land surface modeling communities.

We investigated the water use of Caatinga vegetation, the largest seasonally dry forest in South America. We identified and analysed the environmental phenological drivers in woody species and their relationship with transpiration. To monitor the phenological evolution, we used remote sensing indices at different spatial and temporal scales: normalized difference vegetation index (NDVI), soil adjusted vegetation index (SAVI), and green chromatic coordinate (GCC). To represent the phenology, we used the GCC extracted from in-situ automated digital camera images; indices calculated based on sensors included NDVI, SAVI and GCC from Sentinel-2A and B satellites images, and NDVI products MYD13Q1 and MOD13Q1 from a moderate-resolution imaging spectroradiometer (MODIS). Environmental drivers included continuously monitored rainfall, air temperature, soil moisture, net radiation, and vapour pressure deficit. To monitor soil water status and vegetation water use, we installed soil moisture sensors along three soil profiles and sap flow sensors for five plant species. Our study demonstrated that the near-surface GCC data played an important role in permitting individual monitoring of species, whereas the species’ sap flow data correlated better with NDVI, SAVI, and GCC than with species’ near-surface GCC. The wood density appeared to affect the transpiration cessation times in the dry season, given that species with the lowest wood density reach negligible values of transpiration earlier in the season than those with high woody density. Our results show that soil water availability was the main limiting factor for transpiration during more than 80% of the year, and that both the phenological response and water use are directly related to water availability when relative saturation of the soil profile fell below 0.25.

Abstract Background The recent inclusion of the cocoa sector as an option for carbon storage necessitates the need to quantify the C stocks in cocoa systems of Ghana. Results Using farmers’ fields, the carbon (C) stocks in shaded and unshaded cocoa systems selected from the Eastern (ER) and Western (WR) regions of Ghana were measured. Total ecosystem C (biomass C + soil C to 60 cm depth) ranged from 81.8 to 153.9 Mg C/ha. The bulk (~89 %) of the systems’ C stock was stored in the soils. The total C stocks were higher in the WR (137.8 ± 8.6 Mg C/ha) than ER (95.7 ± 8.6 Mg C/ha). Conclusion Based on the cocoa cultivation area of 1.45 million hectares, the cocoa sector in Ghana potentially could store 118.6–223.2 Gg C in cocoa systems with cocoa systems aged within 30 years regardless of shade management. Thus, the decision to include the cocoa sector in the national carbon accounting emissions budget of Ghana is warranted.

The potential effect of climate change on regional suitability for cocoa cultivation is a serious economic concern for West Africa—especially for Ghana and Côte d’Ivoire, whose cocoa cultivation accounts for respectively ∼19% and ∼45% of world production. Here, we present a modelling and observational study of cocoa net primary productivity (NPP) in present day and future West African climates. Our analysis uses a data assimilation technique to parameterise a process-based land-surface model. The parameterisation is based on laboratory observations of cocoa, grown under both ambient and elevated CO _2 . Present day and end of 21st century cocoa cultivation scenarios are produced by driving the parameterised land-surface model with output from a high-resolution climate model. This represents a significant advance on previous work, because unlike the CMIP5 models, the high-resolution model used in this study accurately captures the observed precipitation seasonality in the cocoa-growing regions of West Africa—a key sensitivity for perennials like cocoa. We find that temperature is projected to increase significantly and precipitation is projected to increase slightly, although not in all parts of the region of interest. We find, furthermore, that the physiological effect of higher atmospheric CO _2 concentration ameliorates the impacts of high temperature and variation in precipitation thereby reducing some of the negative impacts of climate change and maintaining NPP in West Africa, for the whole 21st Century, even under a high emissions scenario. Although NPP is an indicator of general vegetation condition, it is not equivalent to yield or bean quality. The study presented here is, nevertheless, a strong basis for further field and modelling studies of cultivation under elevated CO _2 conditions.

We assessed the potential for using optical functional types as effective markers to monitor changes in vegetation in floodplain meadows associated with changes in their local environment. Floodplain meadows are challenging ecosystems for monitoring and conservation because of their highly biodiverse nature. Our aim was to understand and explain spectral differences among key members of floodplain meadows and also characterize differences with respect to functional traits. The study was conducted on a typical floodplain meadow in UK (MG4-type, mesotrophic grassland type 4, according to British National Vegetation Classification). We compared two approaches to characterize floodplain communities using field spectroscopy. The first approach was sub-community based, in which we collected spectral signatures for species groupings indicating two distinct eco-hydrological conditions (dry and wet soil indicator species). The other approach was “species-specific”, in which we focused on the spectral reflectance of three key species found on the meadow. One herb species is a typical member of the MG4 floodplain meadow community, while the other two species, sedge and rush, represent wetland vegetation. We also monitored vegetation biophysical and functional properties as well as soil nutrients and ground water levels. We found that the vegetation classes representing meadow sub-communities could not be spectrally distinguished from each other, whereas the individual herb species was found to have a distinctly different spectral signature from the sedge and rush species. The spectral differences between these three species could be explained by their observed differences in plant biophysical parameters, as corroborated through radiative transfer model simulations. These parameters, such as leaf area index, leaf dry matter content, leaf water content, and specific leaf area, along with other functional parameters, such as maximum carboxylation capacity and leaf nitrogen content, also helped explain the species’ differences in functional dynamics. Groundwater level and soil nitrogen availability, which are important factors governing plant nutrient status, were also found to be significantly different for the herb/wetland species’ locations. The study concludes that spectrally distinguishable species, typical for a highly biodiverse site such as a floodplain meadow, could potentially be used as target species to monitor vegetation dynamics under changing environmental conditions.

Over the next few decades, it is expected that increasing fossil fuel prices will lead to a proliferation of energy crop cultivation initiatives. The environmental sustainability of these activities is thus a pressing issue—particularly when they take place in vulnerable regions, such as West Africa. In more general terms, the effect of increased CO _2 concentrations and higher temperatures on biomass production and evapotranspiration affects the evolution of the global hydrological and carbon cycles. Investigating these processes for a C4 crop, such as sugarcane, thus provides an opportunity both to extend our understanding of the impact of climate change, and to assess our capacity to model the underpinning processes. This paper applies a process-based crop model to sugarcane in Ghana (where cultivation is planned), and the São Paulo region of Brazil (which has a well-established sugarcane industry). We show that, in the Daka River region of Ghana, provided there is sufficient irrigation, it is possible to generate approximately 75% of the yield achieved in the São Paulo region. In the final part of the study, the production of sugarcane under an idealized temperature increase climate change scenario is explored. It is shown that doubling CO _2 mitigates the degree of water stress associated with a 4 °C increase in temperature.

Classical operational research (OR) is mainly concerned with the use of mathematical techniques and models used in decision-making situations. The basic assumptions of OR presuppose that the structure of the world is one of order and predictability. Although this positivistic approach produces significant results when levels of certainty and initial conditions are stable, it is limited when faced with an acknowledgement of the complex nature of the real world. This paper aims to highlight that by drawing on a general understanding of complexity theory, classical OR approaches can be enriched and broadened by adopting an epistemology based on the assumption that the underlying mechanisms governing the world are complex. It is argued that complexity theory (as interpreted by the philosopher Paul Cilliers) acknowledges the complex nature of the real world and helps to identify the characteristics of complex phenomena. By aligning OR epistemologies with the acknowledgment of complexity, new modelling methods could be developed. In addition, the implications for knowledge generating processes through boundary setting, as well as the provisional nature of such knowledge and what (ethical) responsibilities accompany the study of complex phenomena, will be discussed. Examples are presented to highlight the epistemological implications of complexity thinking for OR.

This article analyses two Venda ngano narratives that portray coming-of-age experiences. Viewed in juxtaposition, they express the radical shift from premodern modes of material and symbolic production to the reified consciousness of capitalist relations. This shift implicates the rootedness of local world views and global market forces within colonial and Western history, as well as contemporary political and economic conditions. The first narrative accordingly describes a classic rite of passage towards adulthood and citizenship within an ancient, precolonial world. Its protagonist is the culture hero whose society prioritises qualities and ideals like spirituality and social integration. In contrast, the second story is located in the colonial world. Its young hero migrates from his rural village to the city, and his adventure is an embryonic representation of the sociopolitical and racial dynamics of the colonial encounter. His actions evolve within a modernist world view, specifically a rational materialism driven by a teleology of progress that conceives economic organisation as the mediator of social relationships and personal fulfilment. The engagement of these diverse world views with history is explored from a perspective that aligns the ancient Venda concept of zwivhuya with Fromm’s notion of qualitative freedom, of actualisation in all realms of human experience and of transcendence in all forms. The resplendent materiality presented in the second narrative is accordingly argued to conceal a spectre of fear and incomplete selfawareness. This poses a dilemma that speaks to all humanity, namely the need to transform the actual poverty of reified materiality into the wealth of an integrated world.

Transcendence has lost its metaphysical moorings and the tendency in postmodernity is the sublimation of transcendence within a conceptual framework of immanence. In other words, transcendence, in a postmetaphysical world, is fully and absolutely actualised or embodied. The consequent question arises: Is there still a need for the concept of transcendence and how should this transcendence be understood in the religious context, in particular? This question is explored by first analysing transcendence within the science-religion discourse. Secondly, Sally McFague’s theology is discussed as an example of a theology of radical immanence, and lastly Gilles Deleuze’s concept of radical immanence is explored. I argue that an understanding of embodied religion in a radical immanent way raises some intrusive questions concerning both the concept of transcendence and religion. A reinterpretation of transcendence might, however, make it possible to understand embodied religion not only in radical immanent terms.

Transcendence has lost its metaphysical moorings and the tendency in postmodernity is the sublimation of transcendence within a conceptual framework of immanence. In other words, transcendence, in a postmetaphysical world, is fully and absolutely actualised or embodied. The consequent question arises: Is there still a need for the concept of transcendence and how should this transcendence be understood in the religious context, in particular? This question is explored by first analysing transcendence within the science-religion discourse. Secondly, Sally McFague’s theology is discussed as an example of a theology of radical immanence, and lastly Gilles Deleuze’s concept of radical immanence is explored. I argue that an understanding of embodied religion in a radical immanent way raises some intrusive questions concerning both the concept of transcendence and religion. A reinterpretation of transcendence might, however, make it possible to understand embodied religion not only in radical immanent terms.

In philosophy and theology there exists a complex relation between timelessness, Trinity and temporality. Timelessness is an age-old attribute given to God in philosophical and theological traditions, but within the last century’s development of trinitarian theology new emphasis has been placed on God’s temporality. This article discusses the trinitarian theologian Robert W Jenson’s understanding of God’s “temporal infinity” as well as the theologian Antje Jackelén’s theology of time. Their proposed concepts of God’s time/eternity is analysed in terms of the contemporary philosophical and scientific debates on the nature of time. Although Jenson’s and Jackelén’s conceptions of God’s time/eternity might, to a great extent, be philosophically sound, they still have some unresolved – perhaps more theological than philosophical – implications.

In philosophy and theology there exists a complex relation between timelessness, Trinity and temporality. Timelessness is an age-old attribute given to God in philosophical and theological traditions, but within the last century’s development of trinitarian theology new emphasis has been placed on God’s temporality. This article discusses the trinitarian theologian Robert W Jenson’s understanding of God’s “temporal infinity” as well as the theologian Antje Jackelén’s theology of time. Their proposed concepts of God’s time/eternity is analysed in terms of the contemporary philosophical and scientific debates on the nature of time. Although Jenson’s and Jackelén’s conceptions of God’s time/eternity might, to a great extent, be philosophically sound, they still have some unresolved – perhaps more theological than philosophical – implications.