Biomass growth and carbon dioxide sequestration with mineral fertilizer and biological fertilizer in north Sweden

Denna studie är en uppföljning på ett mastersarbete som är del av ett större projekt som heter ”Kolsänkor Norrbotten”. Projektet handlar om att jämföra bionäring (avloppsslam) och mineralnäring på 22 skogsbestånd utspridda i Norrbotten. Dessa bestånd gödslades mellan 2006 och 2008. I mastersarbetet och i denna studie fokuseras det enbart på tre bestånd som är lokaliserade utanför Överkalix. Dessa bestånd gödslades 2006. En tredjedel gödslades med mineralnäring med en kvävehalt på 132 - 176 kilogram per hektar och tre år efter gödslades det ytterligare 150 kilogram kvävehalt per hektar. Bionäringsdelen gödslades det med en kvävehalt på 562 – 821 kilogram per hektar. Resterande tredjedel utgjordes av kontrollytor. Totalt är det 175 provytor som är utspridda på 186 hektar. Alla träd som hade tidigare registrerats klavades in i provytorna. Inmätningar av träden har gjorts 2007, 2009 och 2022. Denna studie räknar på hur stor biomassatillväxten varit mellan 2007 och 2022 med hjälp av biomassafunktioner. Syftet med denna studie är att undersöka om det finns tillväxtpotential till högre koldioxidinlagring i norra Sverige genom att mäta utvecklingen under en period på femton år efter att försökbestånden gödslats. Detta för att få ett mått på hur mycket koldioxid varje avdelning i respektive bestånd har bundit. Resultatet och slutsatsen för denna studie är att det har varit en liknande tillväxt på ytor gödslade med bionäring som på ytor gödslade med mineralnäring. Biomassatillväxten har i båda fallen i medeltal varit ungefär 1,9 ton torrvikt per hektar högre än för de obehandlade ytorna. Koldioxidlagringen har i genomsnitt ökat med ungefär 3,4 ton CO2 per hektar och år. Detta är nästan en fördubbling jämfört med de obehandlade avdelningarna mellan 2007 och 2022. Det finns inget i undersökningen som tyder på att tillväxtökningen utgjort en mortalitetsrisk för träden genom att ge en ökad risk för stormskador. Bionäring har kanske potential att ersätta mineralnäring. En fördel med bionäringen är att det sannolikt går åt mindre energi att producera kvävet för bionäringen. Det skulle dock behöva undersökas mer vad för energikälla som används för att torka bionäringen och hur mycket utsläpp det genererar. Det har här inte räknats på hur mycket koldioxid som släppts ut vid transporten från reningsverket respektive fabriken till skogen. Det blir dock stora volymer bionäring att transportera jämfört med mineralnäringen för att få samma gödslingseffekt. Kanske är kvävet från mineralnäringen därför fortfarande det mest tillväxteffektiva att gödsla med, eftersom det där krävs betydligt mindre kväve för att få motsvarande tillväxt som för bionäringen.This study is a follow-up to a master's thesis that is part of a larger project called "Carbon storage in Northern Sweden". The project is about comparing biological fertilization (sewage sludge) and synthetic fertilization on 22 forest stands scattered in Norrbotten. These stands were fertilized between 2006 and 2008. In the master's thesis and in this study, it focuses on three stands that are located outside Överkalix. These stands were fertilized in 2006. One third was fertilized with synthetic nutrition with a nitrogen content of 132 - 176 kilograms per hectare and three years after an additional fertilization of 150 kilograms nitrogen content per hectare. Biological nutrition fertilized with a nitrogen content of 562 – 821 kilograms per hectare. The remaining third constituted as control sites. In total, there are 175 sample plots spread over 186 hectares. All trees that had previously been calipered in the sample plots. Measurements of the trees have been made in 2007, 2009, and 2022. This study calculates how large the biomass growth been between 2007 and 2022 using biomass functions. The purpose of this study is to investigate whether there is growth potential for higher carbon dioxide sequestration in northern Sweden by measuring the development under a fifteen-year period after the research stands were fertilize. This is to get a measure of how much carbon dioxide each site in the respective stand has sequestered. The result and conclusion of this study is that there has been a similar growth in the biological fertilized as on the synthetic fertilized sites. Biomass growth has in both cases been by an average of approximately 1.9 tons of dry weight per hectare higher than the untreated sites. Carbon dioxide storage has increased with an average value of approximately 3.4 tons of CO2 per hectare and year. This is almost double amount compared to the untreated sites between 2007 and 2022. There is no indication in this study that the increase of growth poses a mortality risk to the trees through giving an increased risk of storm damage. Biological fertilization may have the potential to replace synthetic fertilization. An advantage of the biological fertilization is that it probably takes less energy to produce the nitrogen for the biological fertilization. However, it would be necessary to investigate more what kind of energy source is used to dry the biological fertilization and how much emissions it generates. It has not been calculated here how much carbon dioxide was released during the transport from the treatment plant or the factory to the forest. There are though large volumes of biological fertilization to transport compared to synthetic fertilization to get the same growth effect. Perhaps nitrogen from the synthetic fertilization is still the most growth efficient to fertilize with because it requires much less nitrogen to get an equivalent growth as for the biological fertilization

The cognitive operator 4.0

While previous Industrial Revolutions have increasingly seen the human as a cog in the system, each step reducing the cognitive content of work, Industry 4.0 contrarily views the human as a knowledge worker putting increased focus on cognitive skills and specialised craftsmanship. The opportunities that technological advancement provide are in abundance and to be able to fully take advantage of them, understanding how humans interact with increasingly complex technology is crucial. The Operator 4.0, a framework of eight plausible scenarios attempting to highlight what Industry 4.0 entails for the human worker, takes advantage of extended reality technology; having real-time access to large amounts of data and information; being physically enhanced using powered exoskeletons or through collaboration with automation; and finally real-time monitoring of operator status and health as well as the possibility to collaborate socially with other agents in the Industrial Internet of Things, Services, and People. Some of these will impose larger cognitive challenges than others and this paper presents and discusses parts of the Operator 4.0 projections that will have implications on cognitive work

Towards Mirror Symmetry as Duality for Two-Dimensional Abelian Gauge Theories

Superconformal sigma models with Calabi--Yau target spaces described as complete intersection subvarieties in toric varieties can be obtained as the low-energy limit of certain abelian gauge theories in two dimensions. We formulate mirror symmetry for this class of Calabi--Yau spaces as a duality in the abelian gauge theory, giving the explicit mapping relating the two Lagrangians. The duality relates inequivalent theories which lead to isomorphic theories in the low-energy limit. This formulation suggests that mirror symmetry could be derived using abelian duality. The application of duality in this context is complicated by the presence of nontrivial dynamics and the absence of a global symmetry. We propose a way to overcome these obstacles, leading to a more symmetric Lagrangian. The argument, however, fails to produce a derivation of the conjecture.Comment: 14 pages, latex, no figure

Mechanics of universal horizons

Modified gravity models such as Ho\v{r}ava-Lifshitz gravity or Einstein-{\ae}ther theory violate local Lorentz invariance and therefore destroy the notion of a universal light cone. Despite this, in the infrared limit both models above possess static, spherically symmetric solutions with "universal horizons" - hypersurfaces that are causal boundaries between an interior region and asymptotic spatial infinity. In other words, there still exist black hole solutions. We construct a Smarr formula (the relationship between the total energy of the spacetime and the area of the horizon) for such a horizon in Einstein-{\ae}ther theory. We further show that a slightly modified first law of black hole mechanics still holds with the relevant area now a cross-section of the universal horizon. We construct new analytic solutions for certain Einstein-{\ae}ther Lagrangians and illustrate how our results work in these exact cases. Our results suggest that holography may be extended to these theories despite the very different causal structure as long as the universal horizon remains the unique causal boundary when matter fields are added.Comment: Minor clarifications. References update

Triple Interference, Non-linear Talbot Effect and Gravitization of the Quantum

Recently we have discussed a new approach to the problem of quantum gravity in which the quantum mechanical structures that are traditionally fixed, such as the Fubini-Study metric in the Hilbert space of states, become dynamical and so implement the idea of gravitizing the quantum. In this paper we elaborate on a specific test of this new approach to quantum gravity using triple interference in a varying gravitational field. Our discussion is driven by a profound analogy with recent triple-path interference experiments performed in the context of non-linear optics. We emphasize that the triple interference experiment in a varying gravitational field would deeply influence the present understanding of the kinematics of quantum gravity and quantum gravity phenomenology. We also discuss the non-linear Talbot effect as another striking phenomenological probe of gravitization of the geometry of quantum theory.Comment: 27 pages, 2 figures. arXiv admin note: text overlap with arXiv:2203.1713

Just transition in the post-pandemic city

This paper asks how the pandemic has affected climate governance, with a specific focus on just transition in cities. We respond to Westman and Castán Broto’s (Citation2021) challenge that three assumptions are frequently reproduced in the urban climate governance literature and ask: (1) Are social justice and environmental sustainability separated? (2) Does a sectoral perspective on cities constrain conceptions of climate justice? and (3) Is there action rather than just plans? We address these questions by studying three cities in the South West of England (Bristol, Bath, and Exeter) that have expressed aspirations for rapid and just transition to net zero. There are promising signs of climate action, although the pandemic slowed it down somewhat. Climate justice is not sufficiently embedded in plans or actions. Commitment to just transition is present but partial and often unspecified. Social justice and ecological sustainability are too often treated as separate goals, more likely to come into conflict with each other, than addressed jointly. Too much climate work in cities takes place in silos around energy and transport but separate from other sectors. There is a notable failure to engage with civil society for a just transition. We conclude that for cities to truly implement a just transition, better engagement with grassroots actors from across sectors and parts of society is necessary. The development of tools which support cities to analyse the complex interplay of distributional, recognitional, participatory and restorative aspects of justice could be an important part of delivering this change