Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2022
Authors
Olle Anderbrant Ann-Kristin Isaksson Line Beate Lersveen Christer Löfstedt Sigrid Mogan Elisabeth Ôberg Marja Rantanen Glenn Svensson Gunda ThömingAbstract
No abstract has been registered
Abstract
Digestate, a by-product from anaerobic digestion of organic materials such as animal manure, is considered a suitable plant fertilizer. However, due to its bulkiness and low economic value, it is costly to transport over long distances and store for long periods. Refinement processes to valorize digestate and facilitate its handling as a fertilizer include precipitation of phosphorus-rich mineral compounds, such as struvite and calcium phosphates, membrane filtration methods that concentrate plant nutrients in organic products, and carbonization processes. However, phosphorus retention efficiency in output products from these processes can vary considerably depending on technological settings and characteristics of the digestate feedstock. The effects of phosphorus in plant fertilizers (including those analogous or comparable to refined digestate products) on agronomic productivity have been evaluated in multiple experiments. In this review, we synthesized knowledge about different refinement methods for manure-based digestate as a means to produce phosphorus fertilizers, thereby providing the potential to increase phosphorus retention in the food production chain, by combining information about phosphorus flows in digestate refinement studies and agronomic fertilizer studies. It was also sought to identify the range, uncertainty, and potential retention efficiency by agricultural crops of the original phosphorus amount in manure-based digestate. Refinement chains with solid/wet phase separation followed by struvite or calcium phosphate precipitation or membrane filtration of the wet phase and carbonization treatments of the solid phase were included. Several methods with high potential to extract phosphorus from manure-based wet phase digestate in such a way that it could be used as an efficient plant fertilizer were identified, with struvite precipitation being the most promising method. Synthesis of results from digestate refinement studies and agronomic fertilizer experiments did not support the hypothesis that solid/wet separation followed by struvite precipitation, or any other refinement combination, results in higher phosphorus retention than found for unrefined digestate. Further studies are needed on the use of the phosphorus in the solid phase digestate, primarily on phosphorus-rich soils representative of animal-dense regions, to increase understanding of the role of digestate refinement (particularly struvite precipitation) in phosphorus recycling in agricultural systems.
Authors
Abirami Ramu Ganesan Mohan Kannan Durairaj Karthick Rajan Arti A. Pillay Munisamy Shanmugam Palanivel Sathishkumar Johan Johansen Brijesh K. TiwariAbstract
Phycoerythrin (PE) is a photosensitive red pigment from phycobiliprotein family predominantly present in the red algae. The concentration of PE depends on photon flux density (PFD) and the quality of light absorbed by the algae tissue. This necessitates robust techniques to extract PE from the embedded cell-wall matrix of the algal frond. Similarly, PE is sensitive to various factors which influence its stability and purity of PE. The PE is extracted from Red algae through different extraction techniques. This review explores an integrative approach of fractionating PE for the scaling-up process and commercialization. The mechanism for stabilizing PE pigment in food was critically evaluated for further retaining this pigment within the food system. The challenges and possibilities of employing efficient extraction for industrial adoption are meticulously estimated. The techniques involved in the sustainable way of extracting PE pigments improved at a laboratory scale in the past decade. Although, the complexity of industrial-scale biorefining was found to be a bottleneck. The extraction of PE using benign chemicals would be safe for food applications to promote health benefits. The precise selection of encapsulation technique with enhanced sensitivity and selectivity of the membrane would bring better stability of PE in the food matrix.
Authors
Leonardo H. Teixeira Guilherme G. Mazzochini Johannes Kollmann Gislene GanadeAbstract
1. Little attention has been paid to phylogenetic diversity during restoration initiatives. Because plant phylogenetic distance can be a surrogate for functional diversity, its consideration could foster the restoration of degraded areas. 2. This study investigates the influence of species richness and phylogenetic relatedness during early restoration of a riparian forest located between the Atlantic Forest and semi-arid ecosystems in NE Brazil. The restoration experiment was established along a perennial stream in Monte Alegre, RN, investigating the significance of species richness and phylogenetic diversity for sapling survival and growth of the restored communities. 3. We used phylogenetic information on 47 tree species naturally occurring at the study site. The resulting phylogenetic tree had a basal node with three major clades. To implement the experiment, three species from each clade were randomly selected, resulting in nine species (from five families). We defined five levels of diversity: (i) no planting, (ii) monoculture, (iii) three phylogenetically related species (same clade), (iv) three phylogenetically distant species (different clades) and (v) nine species. The experiment consisted of 96 (12 m × 10 m) plots established along the two margins of the stream. Overall, 1656 saplings (20–50 cm) were planted in September 2015 (184 per species). We tested whether the survival and growth of saplings are influenced by the number of species planted and phylogenetic distance among them. 4. We assessed plant mortality and growth during two consecutive years (2016 and 2017). Survival was lower but relative growth was higher for plants near the stream. After controlling for differences in initial size, plots with phylogenetically distant species produced significantly taller plants, but only when occurring near the stream. Diversity treatments did not influence plant survival, while initial size determined plant survival and growth. 5. Our findings show that greater phylogenetic distance led to increased plant growth, probably, because of the presence of functionally divergent species that use resources in a complementary way. Therefore, plant phylogenetic relatedness should be considered during the design of restored communities to improve the outcomes of future restoration initiatives.
Authors
Lena Wohlgemuth Pasi Rautio Bernd Ahrends Alexander Russ Lars Vesterdal Peter Waldner Volkmar Timmermann Nadine Eickenscheidt Alfred Fürst Martin Greve Peter Roskams Anne Thimonier Manuel Nicolas Anna Kowalska Morten Ingerslev Päivi Merilä Sue Benham Carmen Iacoban Günter Hoch Christine Alewell Martin JiskraAbstract
Despite the importance of vegetation uptake of atmospheric gaseous elemental mercury (Hg(0)) within the global Hg cycle, little knowledge exists on the physiological, climatic, and geographic factors controlling stomatal uptake of atmospheric Hg(0) by tree foliage. We investigate controls on foliar stomatal Hg(0) uptake by combining Hg measurements of 3569 foliage samples across Europe with data on tree species' traits and environmental conditions. To account for foliar Hg accumulation over time, we normalized foliar Hg concentration over the foliar life period from the simulated start of the growing season to sample harvest. The most relevant parameter impacting daily foliar stomatal Hg uptake was tree functional group (deciduous versus coniferous trees). On average, we measured 3.2 times higher daily foliar stomatal Hg uptake rates in deciduous leaves than in coniferous needles of the same age. Across tree species, for foliage of beech and fir, and at two out of three forest plots with more than 20 samples, we found a significant (p<0.001) increase in foliar Hg values with respective leaf nitrogen concentrations. We therefore suggest that foliar stomatal Hg uptake is controlled by tree functional traits with uptake rates increasing from low to high nutrient content representing low to high physiological activity. For pine and spruce needles, we detected a significant linear decrease in daily foliar stomatal Hg uptake with the proportion of time during which water vapor pressure deficit (VPD) exceeded the species-specific threshold values of 1.2 and 3 kPa, respectively. The proportion of time within the growing season during which surface soil water content (ERA5-Land) in the region of forest plots was low correlated negatively with foliar Hg uptake rates of beech and pine. These findings suggest that stomatal uptake of atmospheric Hg(0) is inhibited under high VPD conditions and/or low soil water content due to the regulation of stomatal conductance to reduce water loss under dry conditions. Other parameters associated with forest sampling sites (latitude and altitude), sampled trees (average age and diameter at breast height), or regional satellite-observation-based transpiration product (Global Land Evaporation Amsterdam Model: GLEAM) did not significantly correlate with daily foliar Hg uptake rates. We conclude that tree physiological activity and stomatal response to VPD and soil water content should be implemented in a stomatal Hg model to assess future Hg cycling under different anthropogenic emission scenarios and global warming.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Major development projects along rivers, like reservoirs and other hydraulic structures, have changed not only river discharges but also sediment transport. Thus, changes in river planforms can be observed in such rivers. In addition, river centerline migrations can be witnessed. The Mahaweli River is the longest in Sri Lanka, having the largest catchment area among the 103 major river basins in the country. The river has been subjected to many development projects over the last 50 years, causing significant changes in the river discharge and sediment transport. However, no research has been carried out to evaluate the temporal and spatial changes in planforms. The current seeks to qualitatively analyze the river planform changes of the Lower Mahaweli River (downstream to Damanewewa) over the past 30 years (from 1991 to 2021) and identify the major planform features and their spatiotemporal changes in the lower Mahaweli River. Analyzing the changes in rivers requires long-term data with high spatial resolution. Therefore, in this research, remotely sensed Landsat satellite data were used to analyze the planform changes of Lower Mahaweli River with a considerably high resolution (30 m). These Landsat satellite images were processed and analyzed using the QGIS mapping tool and a semi-automated digitizing tool. The results show that major changes in river Mahaweli occurred mainly in the most downstream sections of the selected river segment. Further, the river curvature was also comparatively high downstream of the river. An oxbow lake formation was observed over time in the most downstream part of the Mahaweli River after 2011. Centerline migration rates were also calculated with the generated river centerlines. It was found that the rates were generally lower than about 30 m per year, except for at locations where river meandering was observed. The main limitations of this study were the possible misclassifications due to the resolution of images and obstructions caused by cloud cover in the Landsat images. To achieve more accurate estimates, this study could be developed further with quantitative mathematical analysis by also considering the sediment dynamics of the Mahaweli River.
Abstract
The visual impacts of landscape change are important for how people perceive landscapes and whether they consider changes to be positive or negative. Landscape photographs and photographs of landscape elements may capture information about the visual qualities of landscapes and can also be used to illustrate, and even to quantify, how these visual qualities change over time. We developed a methodology for a monitoring scheme, based on taking photographs from exactly the same locations at different points in time. We tested two methods: one where fieldworkers chose freely the location and direction of photographs, and one where photo locations and four out of five directions were predefined. We found that the method using predefined locations provided a representative sample of the visual qualities present in the landscape and was relatively person-independent but missed rare landscape components. The method using free selection of photo locations and directions captured rarities, but the content of the photos varied from photographer to photographer. Considering the strengths and weaknesses of the two approaches, we recommend a method that combines aspects of both when establishing a monitoring scheme based on repeat photography, with predefined locations to ensure that the entire area is covered, and additional freely chosen photo locations to capture special subject matter that would otherwise be missed.
Authors
Axel Mithöfer Michael Riemann Corine Alexis Faehn Anna Mrazova Laura JaakolaAbstract
Global warming is predicted to change the growth conditions for plants and crops in regions at high latitudes (>60° N), including the Arctic. This will be accompanied by alterations in the composition of natural plant and pest communities, as herbivorous arthropods will invade these regions as well. Interactions between previously non-overlapping species may occur and cause new challenges to herbivore attack. However, plants growing at high latitudes experience less herbivory compared to plants grown at lower latitudes. We hypothesize that this finding is due to a gradient of constitutive chemical defense towards the Northern regions. We further hypothesize that higher level of defensive compounds is mediated by higher level of the defense-related phytohormone jasmonate. Because its biosynthesis is light dependent, Arctic summer day light conditions can promote jasmonate accumulation and, hence, downstream physiological responses. A pilot study with bilberry (Vaccinium myrtillus) plants grown under different light regimes supports the hypothesis.