How integrative modelling can break down disciplinary silos

This paper has been published in a peer-reviewed journal as: Kragt, M.E., Robson, B.J. & Macleod, C.J.A. (2013) Modellers’ roles in structuring integrative research projects. Environmental Modelling & Software, 39(1): 322-330. DOI: 10.1016/j.envsoft.2012.06.015Environmental modelling, Interdisciplinary research, Transdisciplinarity, Integration, Research Methods/ Statistical Methods, Q57, Y80, Z19,

Web technologies for environmental big data

Recent evolutions in computing science and web technology provide the environmental community with continuously expanding resources for data collection and analysis that pose unprecedented challenges to the design of analysis methods, workflows, and interaction with data sets. In the light of the recent UK Research Council funded Environmental Virtual Observatory pilot project, this paper gives an overview of currently available implementations related to web-based technologies for processing large and heterogeneous datasets and discuss their relevance within the context of environmental data processing, simulation and prediction. We found that, the processing of the simple datasets used in the pilot proved to be relatively straightforward using a combination of R, RPy2, PyWPS and PostgreSQL. However, the use of NoSQL databases and more versatile frameworks such as OGC standard based implementations may provide a wider and more flexible set of features that particularly facilitate working with larger volumes and more heterogeneous data sources

Woody plant encroachment into grasslands leads to accelerated erosion of previously stable organic carbon from dryland soils

Journal ArticleDrylands worldwide are experiencing rapid and extensive environmental change, concomitant with the encroachment of woody vegetation into grasslands. Woody encroachment leads to changes in both the structure and function of dryland ecosystems and has been shown to result in accelerated soil erosion and loss of soil nutrients. Covering 40% of the terrestrial land surface, dryland environments are of global importance, both as a habitat and a soil carbon store. Relationships between environmental change, soil erosion, and the carbon cycle are uncertain. There is a clear need to further our understanding of dryland vegetation change and impacts on carbon dynamics. Here two grass-to-woody ecotones that occur across large areas of the southwestern United States are investigated. This study takes a multidisciplinary approach, combining ecohydrological monitoring of structure and function and a dual-proxy biogeochemical tracing approach using the unique natural biochemical signatures of the vegetation. Results show that following woody encroachment, not only do these drylands lose significantly more soil and organic carbon via erosion but that this includes significant amounts of legacy organic carbon which would previously have been stable under grass cover. Results suggest that these dryland soils may not act as a stable organic carbon pool, following encroachment and that accelerated erosion of carbon, driven by vegetation change, has important implications for carbon dynamics.University of ExeterRothamsted Research North Wyk

Influence of previous crops and nematicide treatments on root lesion nematode populations and crop yields

Nous avons étudié au champ l'influence du précédent cultural, de la séquence culturelle et de traitements à l'aldicarbe sur les populations de nematodes des nodosités et sur les rendements de diverses cultures à l'île-du Prince-Édouard. La culture précédente a eu le plus grand impact sur le nombre de nematodes. Les séquences des cultures ont parfois eu une influence sur les populations de nematodes des nodosités (principalement Pratylenchus penetrans) et sur les rendements. Dans les champs commerciaux d'orge (Hordeum vulgare), les nematodes des nodosités étaient plus nombreux lorsque l'orge suivait une culture combinée de trèfle rouge (Trifolium pratense) et de fléole (Phleum pratense) et les nematodes du rabougrissement (Tylenchorynchus spp., principalement T. dubiuset Merlinius spp.) étaient plus nombreux quand l'orge était semée pendant deux années consécutives. La masse de la matière sèche combinée du feuillage et du grain était plus importante lorsque l'orge était semée auprès des pommes de terre (Solanum tuberosum) et cette masse était plus faible avec deux cultures successives d’orge ou avec un mélange de trèfle rouge et de fléole. En conditions expérimentales au champ, les populations de nématodes des nodosités étaient plus élevées dans les racines d’orge lorsque celle-ci était cultivée après des pommes de terre et les rendements en grain étaient plus faibles lorsque l’orge était cultivée pendant deux années consécutives. Les changements dans les populations de nématodes chez la pomme de terre n’étaient pas associés aux séquences débutant avec le blé (Triticum aestivum) ou l’orge que dans les séquences débutant avec les pommes de terre ou le soya (Glycine max). L’aldicarbe a réduit le nombre de nématodes des nodosités en plus d’accroître les rendements en pommes de terre et en soya.A field study assessing the influence of the previous crop, the crop sequence, and aldicarb treatments on root lesion nematode populations and crop yields was carried out in Prince-Edward-Island, Canada. The most recent crop had the greatest impact on nematode numbers. The crop sequences had an influence in some cases on root lesion nematode populations (primarily Pratylenchus penetrans) and on crop yields. In commercial barley (Hordeum vulgare) fields, root lesion nematodes in roots were greatest when barley followed a red clover (Trifolium pratense) timothy (Phleum pratense) ley, and stunt nematodes (Tylenchorhynchus spp., primarily T. dubius, and Merlinius spp.) were more common when barley followed barley. The combined dry weight of foliage and grain was larger when barley was planted after potato (Solanumtuberosum) and smaller when barley followed barley or a red clover-timothy mixture. Under experimental field conditions, root lesion nematode populations were largest in barley roots when barley followed potato and grain yields were smallest when barley followed barley. Changes in nematode populations in potato were not associated with crop sequences. Potato tuber yields were higher in the sequences that began with wheat (Triticum aestivum) or barley than in the sequences that began with potato or soybean (Glycine max). Aldicarb reduced the numbers of root lesion nematodes in roots with concomitant yield increases in potato and soybean

Intensive management in grasslands causes diffuse water pollution at the farm scale

Arable land use is generally assumed to be the largest contributor to agricultural diffuse pollution. This study adds to the growing evidence that conventional temperate intensively managed lowland grasslands contribute significantly to soil erosion and diffuse pollution rates. This is the first grassland study to monitor hydrological characteristics and multiple pollutant fluxes (suspended sediment [SS] and the macronutrients: total oxidized nitrogen-N [TONN], total phosphorus [TP], and total carbon [TC]) at high temporal resolution (monitoring up to every 15 min) over 1 yr. Monitoring was conducted across three fields (6.5-7.5 ha) on the North Wyke Farm Platform, UK. The estimated annual erosion rates (up to 527.4 kg ha-1), TP losses (up to 0.9 kg ha-1), and TC losses (up to 179 kg ha-1) were similar to or exceeded the losses reported for other grassland, mixed land-use, and arable sites. Annual yields of TONN (up to 3 kg ha-1) were less than arable land-use fluxes and earlier grassland N studies, an important result as the study site is situated within a Nitrate Vulnerable Zone. The high-resolution monitoring allowed detailed "system's functioning" understanding of hydrological processes, mobilization- transport pathways of individual pollutants, and the changes of the relative importance of diffuse pollutants through flow conditions and time. Suspended sediment and TP concentrations frequently exceeded water quality guidelines recommended by the European Freshwater Fisheries Directive (25 mg L-1) and the European Water Framework Directive (0.04 mg soluble reactive P L-1), suggesting that intensively managed grasslands pose a significant threat to receiving surface waters. Such sediment and nutrient losses from intensively managed grasslands should be acknowledged in land management guidelines and advice for future compliance with surface water quality standards.NERC-Case PhD awardUK Biotechnology and Biological Sciences Research Counci

Growth, yield and phenology of 2 hybrid papayas (Carica papaya L.) as influenced by method of water application

Highly variable, outcrossed papaya lines irrigated with overhead sprinklers were grown at Yarwun (151.3˚E, 23.75˚S) in Queensland, Australia. The inherent variability made scientifically based comparative studies impractical. The advent of uniform hybrid papaya lines allowed the testing of 2 of these hybrids under 3 irrigation methods, 2 of which had the potential to greatly reduce water use compared with overhead sprinklers. Yields of 92 t/ha.year were achieved by both papaya Hybrids 29 and 1E. Water application method did not influence yield. About 26% of plants were lost due to the phytoplasma diseases dieback, yellow crinkle and mosaic over the life of the trial. Downward yield fluctuations were related to poor fruit set in winter when pollinators (Family Sphingidae) were not present and growth was slow due to hot dry periods affecting fruit set. The resultant fruit (about 6 months later) were small and reduced in number. Irrigation with overhead sprinklers using saline water (1400–4000 S/cm) damaged leaves and reduced growth of plants. Winter spot was most severe in July, August and September, in Hybrid 29 with overhead irrigation. Height of plants 13 weeks after planting was greater under trickle irrigation due to less damage from the saline water supply than in the overhead sprinkler treatment. Hybrid 29 set fruit at 94.3 cm above ground compared with 117.6 cm for Hybrid 1E

Health Sciences Education Rehabilitation (Uganda) : evaluation visit Apr. 7-21, 1994

Reproduction of poor qualit

UK monitoring and deposition of tephra from the May 2011 eruption of Grímsvötn, Iceland

Mapping the transport and deposition of tephra is important for the assessment of an eruption’s impact on health, transport, vegetation and infrastructure, but it is challenging at large distances from a volcano (> 1000 km), where it may not be visible to the naked eye. Here we describe a range of methods used to quantify tephra deposition and impact on air quality during the 21–28 May 2011 explosive basaltic eruption of Grímsvötn volcano, Iceland. Tephra was detected in the UK with tape-on-paper samples, rainwater samples, rainwater chemistry analysis, pollen slides and air quality measurements. Combined results show that deposition was mainly in Scotland, on 23–25 May. Deposition was patchy, with adjacent locations recording different results. Tape-on-paper samples, collected by volunteer citizen scientists, and giving excellent coverage across the UK, showed deposition at latitudes >55°N, mainly on 24 May. Rainwater samples contained ash grains mostly 20–30 μm long (maximum recorded grainsize 80 μm) with loadings of up to 116 grainscm-2. Analysis of rainwater chemistry showed high concentrations of dissolved Fe and Al in samples from N Scotland on 24–27 May. Pollen slides recorded small glass shards (3–4 μm long) deposited during rainfall on 24–25 May and again on 27 May. Air quality monitoring detected increased particulate matter concentrations in many parts of the country. An hourly concentration of particles  53°N) on 24 May but no negative effects on health were reported. Although the eruption column reached altitudes of 20 km above sea level, air mass trajectories suggest that only tephra from the lowest 4 km above sea level of the eruption plume was transported to the UK. This demonstrates that even low plumes could deliver tephra to the UK and suggests that the relative lack of basaltic tephra in the tephrochronological record is not due to transport processes

Understanding spatial variability of soil properties: a key step in establishing field- to farm-scale agro-ecosystem experiments

PublishedNo abstract is available for this article.NERCBBSR