Essays about: "dynamic global vegetation model DGVM"

Showing result 1 - 5 of 9 essays containing the words dynamic global vegetation model DGVM.

  1. 1. Applying LPJ-GUESS on the Arctic: A model evaluation and benchmarking study

    University essay from Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Author : Margot Jeanne Knapen; [2023]
    Keywords : Physical Geography and Ecosystem Analysis; LPJ-GUESS; Arctic; FLUXNET; Gross Primary Productivity; Ecosystem Respiration; Permafrost; Active Layer Thickness; Snow Depth; Earth and Environmental Sciences;

    Abstract : Warming in the Arctic occurs at a much higher rate than the global average, which has a considerable impact on the Arctic terrestrial carbon cycle. Permafrost thawing can release substantial amounts of carbon, whilst tundra shrubification and tree-line advance, on the other hand, may compensate for this. READ MORE

  2. 2. Evaluating a new hydraulic implementation in LPJ-GUESS for three sites in north Europe

    University essay from Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Author : Carl Holmquist; [2023]
    Keywords : Physical Geography and Ecosystem analysis; LPJ-GUESS; drought; sensitivity analysis; evapotranspiration; gross primary production; hydraulic parameters; boreal forest.; Earth and Environmental Sciences;

    Abstract : Drought is projected to increase in frequency and intensity and impacts trees with increased water stress and increased mortality rate. Water stresses can cause hydraulic failure-related mortality or carbon starvation due to tree species having different strategies to deal with water stresses. READ MORE

  3. 3. Evaluating the ability of LPJ-GUESS to simulate the tree size structures of tropical forests

    University essay from Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Author : Margot Jeanne Knapen; [2021]
    Keywords : tropical forests; tree size distributions; LPJ-GUESS; carbon; biomass; sensitivity analysis; Earth and Environmental Sciences;

    Abstract : Tropical forests are of great importance to all living-beings due to their high biodiversity and the valu-able resources, such as food and fuel, they provide. In addition, tropical trees sequester a high amount of carbon and consequently over half of the global forest carbon stock can be found in the tropics. READ MORE

  4. 4. Multitask Convolutional Neural Network Emulators for Global Crop Models - Supervised Deep Learning in Large Hypercubes of Non-IID Data

    University essay from Lunds universitet/Matematisk statistik

    Author : Amanda Nilsson; [2020]
    Keywords : Multitask Learning; Convolutional Neural Network CNN ; Branched Neural Network; Dynamic Global Vegetation Models DGVM ; Automated Feature Extraction; Feature Importance; Supervised Machine Learning; Emulator; Surrogate Model; Response Surface Model; Approximation Model; Metamodeling; Model Composition; Regularization; Robustness; Hyperparameter Optimization; Mathematics and Statistics;

    Abstract : The aim of this thesis is to establish whether a neural network (NN) can be used for emulation of simulated global crop production - retrieved from the computationally demanding dynamic global vegetation model (DGVM) Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS). It has been devoted to elaboration with various types of neural network architectures: Branched NNs capable of processing inputs of mixed data types; Convolutional Neural Network (CNN) architectures able to perform automated temporal feature extraction of the given weather time series; simpler fully connected (FC) structures as well as Multitask NNs. READ MORE

  5. 5. Modelling global Gross Primary Production using the correlation between key leaf traits

    University essay from Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Author : Alexandra Pongrácz; [2017]
    Keywords : ecosystem modelling; leaf longevity; leaf nitrogen content; leaf mass per area; LEIA; LPJ-GUESS; GPP; terrestrial biosphere; Earth and Environmental Sciences; Biology and Life Sciences;

    Abstract : Sophisticated ecosystem models make it possible to evaluate the potential future changes of the carbon sequestration capacity of the terrestrial biosphere, as a response to the rapid environmental and climatic changes. Accuracy of model estimates is however strongly dependent on the parametrisation of driving parameters. READ MORE