Environmental change impacts on the C- and N-cycle of European forests: a model comparison study [Discussion paper]

Forests are important components of the greenhouse gas balance of Europe. There is considerable uncertainty about how predicted changes to climate and nitrogen deposition will perturb the carbon and nitrogen cycles of European forests and thereby alter forest growth, carbon sequestration and N2O emission. The present study aimed to quantify the carbon and nitrogen balance, including the exchange of greenhouse gases, of European forests over the period 2010–2030, with a particular emphasis on the spatial variability of change. The analysis was carried out for two tree species: European beech and Scots pine. For this purpose, four different dynamic models were used: BASFOR, DailyDayCent, INTEGRATOR and Landscape-DNDC. These models span a range from semi-empirical to complex mechanistic. Comparison of these models allowed assessment of the extent to which model predictions depended on differences in model inputs and structure. We found a European average carbon sink of 0.160 ± 0.020 kgC m−2 yr−1 (pine) and 0.138 ± 0.062 kgC m−2 yr−1 (beech) and N2O source of 0.285 ± 0.125 kgN ha−1 yr−1 (pine) and 0.575 ± 0.105 kgN ha−1 yr−1 (beech). The European average greenhouse gas potential of the carbon source was 18 (pine) and 8 (beech) times that of the N2O source. Carbon sequestration was larger in the trees than in the soil. Carbon sequestration and forest growth were largest in central Europe and lowest in northern Sweden and Finland, N. Poland and S. Spain. No single driver was found to dominate change across Europe. Forests were found to be most sensitive to change in environmental drivers where the drivers were limiting growth, where changes were particularly large or where changes acted in concert. The models disagreed as to which environmental changes were most significant for the geographical variation in forest growth and as to which tree species showed the largest rate of carbon sequestration. Pine and beech forests were found to have differing sensitivities to environmental change, in particular the response to changes in nitrogen and precipitation, with beech forest more vulnerable to drought. There was considerable uncertainty about the geographical location of N2O emissions. Two of the models BASFOR and LandscapeDNDC had largest emissions in central Europe where nitrogen deposition and soil nitrogen were largest whereas the two other models identified different regions with large N2O emission. N2O emissions were found to be larger from beech than pine forests and were found to be particularly sensitive to forest growth

Cтруктурні, оптичні і термоелектричні властивості плівок та наночастинок ZnO, CZTS, CZTSe для фото- і термоперетворювачів

Дисертаційна робота присвячена оптимізації основних фотоелектричних характеристик, а саме квантового виходу (Q), густини струму короткого замикання (Jsc), ефективності (η) плівкових ФЕП на основі ГП n-CdS(ZnSe, ZnS)/p-(CZTS, CdTe) із струмознімальними контактами n-ITO(ZnO); дослідженню морфологічних особливостей, структурних, субструктурних, оптичних, термоелектричних властивостей та елементного складу плівок ZnO, CZTS, нанесених методом пульсуючого спрей піролізу, для використання у ФЕП та наноструктурованого матеріалу на основі НЧ CZTSe, синтезованих колоїдним методом, для застосування у ТЕП, що можуть працювати паралельно з ФЕП. Встановлені взаємозв’язки між фізико- та хіміко-технологічними умовами нанесення плівок та синтезу НЧ, наноструктурованого матеріалу на їх основі, та структурними, субструктурними, оптичними, термоелектричними властивостями, елементним складом будуть використані для подальшого створення ФЕП та ТЕП з покращеними характеристиками.Диссертационная работа посвящена оптимизации основных фотоэлектрических характеристик, а именно квантового выхода (Q), плотности тока короткого замыкания (Jsc), эфективности (η) плёночных ФЭП на основе ГП n-CdS(ZnSe, ZnS)/p-(CZTS, CdTe) с токособирающими контактами ITO(ZnO); исследованию морфологических особенностей, структурных, субструктурных, оптических, термоэлектрических свойств и элементного состава плёнок ZnO, CZTS, нанесённых методом пульсирующего спрей-пиролиза, для применения у вышеуказанных ФЭП и наноструктурированного материала на основе НЧ CZTSe, синтезированных колоидальным методом, для использования у ТЭП, которые могут работать паралельно с ФЭП. Установленные взаимосвязи между физико- и химико-технологическими условиями нанесения плёнок, синтеза НЧ, наноструктурированного материала на их основе, и структурными, субструктурными, оптическими, термоэлектрическими свойствами, элементным составом будут использованы для создания ФЭП и ТЭП с улучшенными характеристиками.PhD thesis is devoted both to the optimization of basic photoelectric characteristics (quantum yield (Q), density of short circuit current (Jsc), efficiency (η)) of solar cells based on n-CdS(ZnSe, ZnS)/p-(CZTS, CdTe) heterojunctions with n-ITO(ZnO) frontal contacts, and to the investigation of morphological, structural, substructural, optical, thermoelectric properties and chemical composition of: (I) ZnO, CZTS films deposited by spray pyrolysis for application in solar cells; (II) nanostructured materials based on CZTSe nanocrystals synthesized by colloidal method for application in thermoelectric devices which can work simultaneously with solar cells. In the work, modeling approbation was performed by means of investigating the effect of optical and recombination losses on Q, Jsc, η of solar cells based on n-CdS(ZnS)/p-CdTe heterojunctions. Afterwards, the investigation of these losses on the photoelectric characteristics of solar cells based on n-CdS(ZnSe, ZnS)/p-CZTS heterojunctions with n-ITO(ZnO) frontal contacts was carried out with the help of the approbated procedure. Taking into account the results of mathematical modeling, the solar cells based on ZnO frontal contact and CZTS absorber layer were considered. For this purpose, the automated setup for the deposition of ZnO and CZTS films by pulsed spray pyrolysis technique was developed. The in-depth investigation of influence of the main growth conditions of layers’ deposition (substrate temperature (Ts), volume of initial precursor (Vs)) on structural (grains size, phase composition, texture quality, lattice parameters), substructural (coherent scattering domain sizes, level of microdeformations and microstresses, density of dislocations at the boundaries and in the volume of subgrains), optical (transmission coefficients, absorbance, band gap) properties and chemical composition of ZnO, CZTS films, as well as the determination of optimal conditions to obtain the specified films were carried out. Since the solar cells operate at the elevated temperatures, it was proposed to use the additional thermal energy by means of its conversion into electrical energy by use of the thermoelectric devices. For this purpose, the nanostructured thermoelectric material based on CZTSe nanocrystals synthesized by the colloidal method was obtained. The influence of kinetic conditions, namely type of phosphonic acid, on morphological (size, shape), structural (phase composition), optical (absorbance, band gap) properties and chemical composition of CZTSe nanocrystals was determined. The influence of chemical composition on the main thermoelectric properties (concentration (p) and mobility ( u ) of majority charge carriers, relative electrical conductivity ( k ), Seebeck coefficient (SZ)) of nanostructured material based on CZTSe nanocrystals was investigated. The established correlations between the film, nanocrystals growth conditions and structural, substructural, optical, thermoelectric properties, chemical composition will be applied for further development of solar cells and thermoelectric devices with the enhanced characteristics

Genomic aberrations associated with outcome in anaplastic oligodendroglial tumors treated within the EORTC phase III trial 26951

Despite similar morphological aspects, anaplastic oligodendroglial tumors (AOTs) form a heterogeneous clinical subgroup of gliomas. The chromosome arms 1p/19q codeletion has been shown to be a relevant biomarker in AOTs and to be perfectly exclusive from EGFR amplification in gliomas. To identify new genomic regions associated with prognosis, 60 AOTs from the EORTC trial 26951 were analyzed retrospectively using BAC-array-based comparative genomic hybridization. The data were processed using a binary tree method. Thirty-three BACs with prognostic value were identified distinguishing four genomic subgroups of AOTs with different prognosis (p < 0.0001). Type I tumors (25%) were characterized by: (1) an EGFR amplification, (2) a poor prognosis, (3) a higher rate of necrosis, and (4) an older age of patients. Type II tumors (21.7%) had: (1) loss of prognostic BACs located on 1p tightly associated with 19q deletion, (2) a longer survival, (3) an oligodendroglioma phenotype, and (4) a frontal location in brain. Type III AOTs (11.7%) exhibited: (1) a deletion of prognostic BACs located on 21q, and (2) a short survival. Finally, type IV tumors (41.7%) had different genomic patterns and prognosis than type I, II and III AOTs. Multivariate analysis showed that genomic type provides additional prognostic data to clinical, imaging and pathological features. Similar results were obtained in the cohort of 45 centrally reviewed–validated cases of AOTs. Whole genome analysis appears useful to screen the numerous genomic abnormalities observed in AOTs and to propose new biomarkers particularly in the non-1p/19q codeleted AOTs

26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017

This work was produced as part of the activities of FAPESP Research,\ud Disseminations and Innovation Center for Neuromathematics (grant\ud 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud supported by a CNPq fellowship (grant 306251/2014-0)

The use of soil nutrient balances in deriving forest biomass harvesting guidelines specific to region, tree species and soil type in the Netherlands

The substitution of biomass for fossil fuels in energy consumption is a measure to decrease the emissions of greenhouse gases and thereby mitigate global warming. During recent years, this has led to an increasing interest to use tree harvest residues as feedstock for bioenergy. An important concern related to the removal of harvesting residues is, however, the potential adverse effects on soil fertility caused by increased nutrient removal, relative to conventional stem-only harvesting. In the Netherlands this is a major concern, since most forests are located on poor sandy soils. To develop forest harvesting guidelines, we applied a mass balance approach comparing nutrient inputs by deposition and weathering with nutrient outputs by harvesting and leaching for various timber harvesting scenarios, including both stem-only harvesting and additional removal of tree tops and branches. A distinction was made in seven major tree species, six soil types (three sandy soils, loam, clay and peat soils) and nine regions, with clear variations in atmospheric deposition of phosphorus (P), calcium (Ca), magnesium (Mg) and potassium (K). For each region-tree-soil combination we calculated the maximum amounts that can be harvested such that the output of the nutrients Ca, Mg, K and P is balanced with the inputs. Results showed that at current harvesting rates, a negative balance of Ca, Mg, K or P is hardly calculated for the richer loamy to clayey soil types, while depletion can occur for the poorer sandy soils, particularly of P and K. Results are used to derive forest biomass harvesting guidelines, taking the uncertainties in the mass balance approach into account. The role of mitigating management approaches is also discussed.</p

Geostatistical prediction and simulation of European soil property maps

A geostatistical model was developed and applied to predict six soil properties and soil horizon thickness for mineral A, B and C soil horizons at the European scale and quantify the associated prediction uncertainties. The soil properties are pH, organic carbon content, organic nitrogen content, clay and sand contents and bulk density. The geostatistical model takes a regression cokriging approach, in which correlations between soil properties and across soil horizons are taken into account. Non-stationarities in the means and variances are represented by mapping units of the generalised European soil and land cover maps. The model was calibrated using the combined WISE, SPADE 1 and EFSDB databases, which jointly contain approximately 3600 soil profiles, irregularly distributed over Europe. The resulting model showed for most soil properties strong dependencies on soil type and land cover, moderate correlations between soil property residuals, strong correlations across horizons, and moderate spatial correlation of regression residuals. Kriging predictions and simulations were made on a 5 km by 5 km grid. Uncertainties in the resulting maps are large, particularly in under-sampled parts of Europe and in strata with large spatial variation. We conclude that geostatistical prediction and simulation are useful techniques to quantify uncertainties in soil property maps at the European scale, but that many more observations are required to fully exploit the relationship with explanatory variables and improve mapping accuracy. One important advantage of the techniques used is that they yield a full probabilistic model, as required by Monte Carlo uncertainty propagation analyses of spatially distributed dynamic models that use soil properties as uncertain input. In particular, the results of this study have been used to analyse how uncertainty in soil properties propagate through terrestrial greenhouse gas emission models.</p

Geostatistical prediction and simulation of European soil property maps

A geostatistical model was developed and applied to predict six soil properties and soil horizon thickness for mineral A, B and C soil horizons at the European scale and quantify the associated prediction uncertainties. The soil properties are pH, organic carbon content, organic nitrogen content, clay and sand contents and bulk density. The geostatistical model takes a regression cokriging approach, in which correlations between soil properties and across soil horizons are taken into account. Non-stationarities in the means and variances are represented by mapping units of the generalised European soil and land cover maps. The model was calibrated using the combined WISE, SPADE 1 and EFSDB databases, which jointly contain approximately 3600 soil profiles, irregularly distributed over Europe. The resulting model showed for most soil properties strong dependencies on soil type and land cover, moderate correlations between soil property residuals, strong correlations across horizons, and moderate spatial correlation of regression residuals. Kriging predictions and simulations were made on a 5 km by 5 km grid. Uncertainties in the resulting maps are large, particularly in under-sampled parts of Europe and in strata with large spatial variation. We conclude that geostatistical prediction and simulation are useful techniques to quantify uncertainties in soil property maps at the European scale, but that many more observations are required to fully exploit the relationship with explanatory variables and improve mapping accuracy. One important advantage of the techniques used is that they yield a full probabilistic model, as required by Monte Carlo uncertainty propagation analyses of spatially distributed dynamic models that use soil properties as uncertain input. In particular, the results of this study have been used to analyse how uncertainty in soil properties propagate through terrestrial greenhouse gas emission models.</p

Impacts of model structure and data aggregation on European wide predictions of nitrogen and green house gas fluxes in response to changes in livestock, land cover, and land management

Various model approaches have been developed for assessing emissions of different forms of reactive nitrogen in various parts of Europe at various geographic resolutions and for various time periods. The modeling approaches include emission factor approaches, empirical models, simple process-based models, and detailed ecosystem models. In this study, we compared three relatively simple process-based models, developed for the national scale (Integrated NITrogen Impact AssessmenT model On a Regional Scale (INITIATOR2)), European scale (MITERRA) and global scale (integrated model to assess the global environment (IMAGE)), with respect to their response to structural and technological changes in the agricultural systems based on the IPCC B2 baseline scenario for the period 2000-2030. Changes are predicted by the IMAGE model and relate to crop yield, crop area, animal numbers, and N fertilizer inputs. The predicted relative changes by IMAGE are used in INITIATOR2 and MITERRA while relating the animal categories and crop categories in IMAGE to those in the latter models. A comparison was made of NH3, N2O and NOx emissions and N leaching to ground water. We compared predictions for the years 2000 and 2030 for: (i) the Netherlands between INITIATOR2 and MITERRA and (ii) Europe (EU-27 countries) between MITERRA and IMAGE. The results of the comparison are presented and evaluated in view of differences in model structure and the effect of aggregating input data at larger spatial scales

A comparison of disaggregated nitrogen budgets for Danish agriculture using Europe-wide and national approaches

Spatially detailed information on agricultural nitrogen (N) budgets is relevant to identify regions where there is a need for a reduction in inputs in view of various forms of N pollution. However, at the scale of the European Union, there is a lack of consistent, reliable, high spatial resolution data necessary for the calculation of regional N losses. To gain insight in the reduction in uncertainty achieved by using higher spatial resolution input data. This was done by comparing spatially disaggregated agricultural N budgets for Denmark for the period 2000–2010, generated by two versions of the European scale model Integrator, a version using high spatial resolution national data for Denmark (Integrator-DK) and a version using available data at the EU scale (Integrator-EU). Results showed that the national N fluxes in the N budgets calculated by the two versions of the model were within 1–5% for N inputs by fertilizer and manure excretion, but inputs by N fixation and N mineralisation differed by 50–100% and N uptake also differed by ca 25%, causing a difference in N leaching and runoff of nearly 50%. Comparison with an independently derived Danish national budget appeared generally to be better with Integrator-EU results in 2000 but with Integrator-DK results in 2010. However, the spatial distribution of manure distribution and N losses from Integrator-DK were closer to observed distributions than those from Integrator-EU. We conclude that close attention to local agronomic practices is needed when using a leaching fraction approach and that for effective support of environmental policymaking, Member States need to collect or submit high spatial resolution agricultural data to Eurostat.</p