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This thesis sets out a food web framework for size-structured populations. The framework enables an ecological approach to food web modelling as the individual life-history from birth, through maturation, and ultimately death is explicitly resolved with the use of bioenergetics based on individual body size. Each population resolves size-structure through a size-spectrum containing the individual
The scientific knowledge of climate change processes and their worrying future implications for human societies and natural systems has developed considerably during the last decade, but necessary adaptive actions by decision makers have so far been rather limited. There are several causes to this, such as a discrepancy related to the communication between climate scientists and end-users, and the
What’s the aim of my portfolio? How do I get started? How do I present my portfolio at the half-time? How does Mahara work? These are some of the questions that are addressed in the portfolio workshops that the PhD program offers. Upcoming workshops: Thursday 17th of September at 09:00-11:30 Portfolio workshop – get started with your portfolio.Place: Zoom Program:09:00-10:00Question hour with cour
The contribution of forest harvesting to base cation losses and soil acidification has increased in recent years in Sweden, as the demand for bioenergy has increased and the sulphur deposition has decreased. Thus, new policy tools are required to evaluate the progress of the recovery from acidification, and as a basis for forest management recommendations. In this study we introduce and test a con
Physiological processes of terrestrial plants regulate the land-atmosphere exchange of carbon, water, and energy, yet few studies have explored the acclimation responses of mature boreal conifer trees to climate change. Here we explored the acclimation responses of photosynthesis, respiration, and stomatal conductance to elevated temperature and/or CO2 concentration ([CO2]) in a 3-year field exper
Gunnarsson highlights how dialectics can shed light on the relation between love and dominance, foregrounding the crucial role that ontological tensions play in self–other relating. Drawing on Roy Bhaskar’s dialectical critical realist philosophy, she expands on Jessica Benjamin’s analysis of male dominance, as well as other feminist work, and elaborates on the necessity of living-with rather thanGunnarsson highlights how dialectics can shed light on the relation between love and dominance, foregrounding the crucial role that ontological tensions play in self–other relating. Drawing on Roy Bhaskar’s dialectical critical realist philosophy, she expands on Jessica Benjamin’s analysis of male dominance as well as other feminist work, and elaborates on the necessity of living-with rather than
A model for global supply of sand, gravel and cut stone for construction based on a system dynamics model was developed for inclusion in the WORLD6 model. The Sand-Gravel-Stone model simulates production and market supply, demand and price for natural sand and gravel, sand and gravel from crushed rock and cut stone. The model uses market mechanisms where the demand is depending on population size,
Harvesting of wood for bioenergy purpose will probably increase in importance in the future, in order to replace fossil fuel. However, the environmental impact of increased harvesting might be considerable, e.g. on soil and water chemistry, biodiversity and long-term productivity, and in this study we investigate thresholds for sustainable harvesting volumes. The study is based on scientific revie
The atmospheric organic aerosol is a tremendously complex system in terms of chemical content. Models generally treat the mixtures as ideal, something which has been questioned owing to model-measurement discrepancies. We used an oxidation flow reactor to produce secondary organic aerosol (SOA) mixtures containing oxidation products of biogenic (α-pinene, myrcene and isoprene) and anthropogenic (m
Molecular tracers in secondary organic aerosols (SOAs) can provide information on origin of SOA, as well as regional scale processes involved in their formation. In this study 9 carboxylic acids, 11 organosulfates (OSs) and 2 nitrooxy organosulfates (NOSs) were determined in daily aerosol particle filter samples from Vavihill measurement station in southern Sweden during June and July 2012. Severa
Terpene emissions from the top-canopy layer (at 20 m) of one 118-year-old Norway spruce tree were measured between June and September 2013 using a branch chamber. Total terpene emissions varied from 0.05 to 332.5 μg gdw -1 h-1 with a peak in August. Monoterpenes dominated throughout the summer and on average accounted for 65% of the total terpene mass, followed by sesquiterpenes (29%) and isoprene
The contribution of this licentiate thesis lies in the modelling of a multi-echelon inventory system with more general backorder cost structures. Backorder costs are traditionally assumed to be linear, whereas we consider structures that are more general functions of the customers’ time in backorder. The system studied is a two-echelon system with one central warehouse and a number of local sites,The contribution of this licentiate thesis lies in the modelling of a multi-echelon inventory system with more general backorder cost structures. Backorder costs are traditionally assumed to be linear, whereas we consider structures that are more general functions of the customers’ time in backorder. The system studied is a two-echelon system with one central warehouse and a number of local sites,
Biogenic Volatile Organic Compounds (BVOCs) are trace gases other than CO2 and CH4 produced and emitted by the biosphere, where the amounts released depend on climatic factors such as temperature and solar irradiation. However, interpretation of leaf-level measurements is currently hampered by factors such as large within-genotypic variability, measurement height and time in the season. A campaign
The response of evapotranspiration (ET) to warming is of critical importance to the water and carbon cycle of the boreal biome, a mosaic of land cover types dominated by forests and peatlands. The effect of warming-induced vapour pressure deficit (VPD) increases on boreal ET remains poorly understood because peatlands are not specifically represented as plant functional types in Earth system model
The study presents a hydrology concept developed to include lateral water flow in the biogeochemical model ForSAFE. The hydrology concept was evaluated against data collected at Svartberget in the Vindeln Research Forest in Northern Sweden. The results show that the new concept allows simulation of a saturated and an unsaturated zone in the soil as well as water flow that reaches the stream compar
Processes controlling environmental change in the subarctic Pacific Ocean on millennial to orbital timescales are not well understood. Here we use a 230-kyr sedimentary record from the northwest Pacific Ocean to assess the response of late Pleistocene sediment dynamics to orbital forcing. Combining a source-to-sink perspective based on sedimentological records with climate model reanalysis, we rev
As global warming is proceeding due to rising greenhouse gas concentrations, the Earth system moves towards climate states that challenge adaptation. Past Earth system states are offering possible modelling systems for the global warming of the coming decades. These include the climate of the mid-Pliocene (∼ 3 Ma), the last interglacial (∼ 129-116 ka) and the mid-Holocene (∼ 6 ka). The simulations
The yearly, total (dry+wet) deposition of inorganic nitrogen (inorg-N) to Norway spruce forests was estimated with a full spatial coverage over Sweden for a twenty-year period, 2001–2020, based on combined measurements with Teflon string samplers, throughfall deposition and bulk deposition to the open field. The results were based on a novel method to apply estimates of the dry deposition based on
Although renovation costs can lead to rent increases in energy retrofitting, it is often assumed that reductions in energy costs will counterbalance the rent increase. In Swedish multifamily housing, energy costs for heating are however generally included as a fixed component in the monthly rent, meaning that the rent increase after energy retrofitting corresponds to the net change in rent level aAlthough renovation costs can lead to rent increases in energy retrofitting, it is often assumed that reductions in energy costs will counterbalance the rent increase. In Swedish multifamily housing, energy costs for heating are however generally included as a fixed component in the monthly rent, meaning that the rent increase after energy retrofitting corresponds to the net change in rent level a
