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Nitrogen (N) is a key element in terrestrial ecosystems as it influences both plant growth and plant interactions with the atmosphere. Accounting for carbon–nitrogen interactions has been found to alter future projections of the terrestrial carbon (C) cycle substantially. Dynamic vegetation models (DVMs) aim to accurately represent both natural vegetation and managed land, not only from a carbon c
Denna uppsats är skriven vid institutionen för kommunikation och medier vid Lunds Universitet. Den författades av Jakob Lundgren och Adam Mattebo under ämnet media- och kommunikationsvetenskap och den är skriven på en B-nivå. Uppsatsens syfte var att undersöka om användandet av mobilapplikationen Snapchat, som växt väldigt snabbt de senaste åren, skiljde sig åt från andra sociala medier. Uppsatsen
Syftet med denna uppsats är att visa hur staden Lagos har vuxit i storlek och ökat i befolkning mellan åren 1990-2008. Jämförelser över staden för åren 1990, 1999 och 2008 har gjorts så att huvudragen i stadens tillväxt har kunnat visas och analyseras. Baserat på hur staden har vuxit och förändrats under dessa år så har även tre stycken framtidsmodeller för hur Lagos kan tänkas se ut år 2020 produThe aim of this thesis is to show how the city of Lagos has grown in size and population between the years 1990-2008. Comparisons over the city for the years 1990, 1999 and 2008 have been made so that the main characteristics of the city’s growth can be shown and analyzed. Based on this expansion future prospects for the city has been provided through producing three different scenarios on how Lag
Fire frequency is changing globally and is projected to affect the global carbon cycle and climate. However, uncertainty about how ecosystems respond to decadal changes in fire frequency makes it difficult to predict the effects of altered fire regimes on the carbon cycle; for instance, we do not fully understand the long-term effects of fire on soil carbon and nutrient storage, or whether fire-dr
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,
The Integrated Carbon Observation System Research Infrastructure aims to provide long-Term, continuous observations of sources and sinks of greenhouse gases such as carbon dioxide, methane, nitrous oxide, and water vapour. At ICOS ecosystem stations, the principal technique for measurements of ecosystem-Atmosphere exchange of GHGs is the eddy-covariance technique. The establishment and setup of an
The importance of semi-arid ecosystems in the global carbon cycle as sinks for CO 2 emissions has recently been highlighted. Africa is a carbon sink and nearly half its area comprises arid and semi-arid ecosystems. However, the
Temperature is a key constraint on ecosystem respiration but is typically measured at only one or a few points across a study site. Given the exponential relationship between temperature and respiration, small differences in temperature across a heterogeneous ecosystem may result in large differences in respiration fluxes. These differences are not captured in current respiration models which use
Global warming is driving environmental change in the Arctic. However, our current understanding of this change varies strongly among different environmental disciplines and is limited by the number and distribution of field sampling locations. Here, we use a quantitative framework based on multivariate statistical modeling to present the current state of sampling across environmental disciplines
The extreme 2018 hot drought that affected central and northern Europe led to the worst wildfire season in Sweden in over a century. The Ljusdal fire complex, the largest area burnt that year (8995 ha), offered a rare opportunity to quantify the combined impacts of wildfire and post-fire management on Scandinavian boreal forests. We present chamber measurements of soil CO2 and CH4 fluxes, soil mic
The atmospheric boundary layer mediates the exchange of energy, matter, and momentum between the land surface and the free troposphere, integrating a range of physical, chemical, and biological processes and is defined as the lowest layer of the atmosphere (ranging from a few meters to 3 km). In this review, we investigate how continuous, automated observations of the atmospheric boundary layer ca
The forest floor provides an important interface of soil-atmosphere CO2 exchanges but their controls and contributions to the ecosystem-scale carbon budget are uncertain due to measurement limitations. In this study, we deployed eddy covariance systems below- and above-canopy to measure the spatially integrated net forest floor CO2 exchange (NFFE) and the entire net ecosystem CO2 exchange (NEE) at
The ongoing development of the Global Carbon Project (GCP) global methane (CH4) budget shows a continuation of increasing CH4 emissions and CH4 accumulation in the atmosphere during 2000–2017. Here, we decompose the global budget into 19 regions (18 land and 1 oceanic) and five key source sectors to spatially attribute the observed global trends. A comparison of top-down (TD) (atmospheric and tran
Carbon release from the North Pacific in glacial-interglacial cycles has been mainly linked to the North Pacific Intermediate Water (NPIW) formation and associated carbon/nutrient water upwelling and biological productivity changes. However, relationship between NPIW and atmospheric CO2 change in the early interglacial remains unclear. Here we report a high-resolution sediment record of NPIW evolu
Vegetation is an important component in the Earth system, providing a direct link between the biosphere and atmosphere. As such, a representative vegetation pattern is needed to accurately simulate climate. We attempt to model global vegetation (biomes) with a data-driven approach, to test if this allows us to create robust global and regional vegetation patterns. This not only provides quantitati
The important role of fire in regulating vegetation community composition and contributions to emissions of greenhouse gases and aerosols make it a critical component of dynamic global vegetation models and Earth system models. Over 2 decades of development, a wide variety of model structures and mechanisms have been designed and incorporated into global fire models, which have been linked to diff
It is projected that forest disturbances, such as insect outbreaks, will have an increasingly negative impact on forests with a warmer climate. These disturbance events can have a substantial impact on forests' ability to absorb atmospheric CO2, and may even turn forests from carbon sinks into carbon sources; hence, it is important to develop methods both to monitor forest disturbances and to quan
