210f00ff-86e5-47dd-a406-9167af3630af Scenarios Network for Alaska and Arctic Planning uaf-snap-data-tools@alaska.edu 2023-06-02T09:05:58 ISO 19115:2003/19139 1.0 3 2560 1 1861 1 EPSG:3338 ALFRESCO Model outputs - Relative Vegetation Change 2017-10-24 This dataset consists of spatial representations of relative vegetation change produced through summarization of ALFRESCO model outputs. These specific outputs are from the Integrated Ecosystem Model (IEM) project, and are from the linear coupled version using AR5/CMIP5 climate inputs (IEM Generation 2). Alec Bennet Michael Lindgren Tom Kurkowski Scenarios Network for Alaska and Arctic Planning uaf-snap-data-tools@alaska.edu https://catalog.snap.uaf.edu/geonetwork/srv/api/records/210f00ff-86e5-47dd-a406-9167af3630af/attachments/alfresco_rv_preview.png vegetation historical projected modeled https://creativecommons.org/licenses/by/4.0/ 1 eng climatologyMeteorologyAtmosphere 1901-01-15 2100-12-15 -173.4921 -111.2589 51.3482 71.3414 The models and scenarios include: IEM Generation 1, AR4/CMIP3: CCCMA-CGCM3.1(T47) MPI-ECHAM5/MPI-OM under the A1B emission scenario IEM Generation 2, AR5/CMIP5: NCAR-CCSM4 MRI-CGCM3 under RCP 8.5 emission scenario Relative vegetation change was defined as the likelihood of a pixel to transition to a different dominant vegetation type. These parameters were assessed throughout the full spatial domain and 3 temporal domains of the simulations (1900-1999, 2000-2099, and 1900-2099) across all 200 model replicates. We calculated the proportion of years among all the simulations (200 replicate runs x number of years per simulation) that each individual pixel transitioned. Relative Vegetation Change counts the number of times a pixel transitions through all replicates and time and divides that value by the total number of layers (replicates * years) A transition is defined as a pixel changing to a different dominant vegetation type. Transitions occur under several circumstances: A pixel can burn and be reset to an early successional type.(ie. spruce pixel burning and then becoming deciduous). A pixel becomes old enough to transition from an early successional type to a later successional type (ie. deciduous to spruce) Graminoid tundra pixels that are subjected to warming conditions for long periods of time can transition to shrub tundra types. Both graminoid and shrub tundra pixels can become populated by spruce stems and if the spruce basal area accumulation is high enough, it can transition to a spruce type. There are several example map layouts for specific Landscape Conservation Cooperatives in Alaska for for IEM Generation 1 outputs only. For background on ALFRESCO, please refer to the following references: Daniel H. Mann, T. Scott Rupp, Mark A. Olson, and Paul A. Duffy (YEAR) Is Alaska's Boreal Forest Now Crossing a Major Ecological Threshold? Arctic, Antarctic, and Alpine Research 2012 44 (3), 319-331 GeoTIFF 1.0 http://data.snap.uaf.edu/data/IEM/Outputs/ALF/Gen_1a/alfresco_relative_spatial_outputs/relative_vegetation_change/AR5_CMIP5 WWW:LINK-1.0-http--link URL to web-accessible folder containing downloads for this data set SNAP data products are value added products that build off of other datasets that have been accepted by the scientific community as some of the highest quality climate data available. Please see www.uaf-snap.org to explore how our data is produced.