Climate Refugia - Baseline (Historical) 1981 - 2010

This raster dataset represents habitat types (natural vegetation communities) and their distribution across the array of climate conditions that each separate habitat type is found in under the baseline climate conditions. A 2015 map of the state's natural vegetation compiled from multiple sources was classified to the National Vegetation Classification Standard's mid-level classification, called "Macrogroup". Thirty one natural vegetation macrogroups are identified in the map, covering 99.87% of the state's natural terrestrial vegetation, and occupying 353,271 km2.

This serves as the foundation from which habitat types will be exposed to predicted changes in climate. Data are arrayed across 0 to 1 in terms of their exposure to current climate conditions. This data layer provides a baseline of vegetation adapted to "historic" conditions; i.e. climate conditions from the recent past; 1980-2010.

Data and Resources

Additional Info

Field Value
Last Updated February 28, 2025, 07:37 (UTC)
Created February 28, 2025, 07:37 (UTC)
category /Forest and Shrubland Resilience/Disturbance
collection_name California Landscape Metrics
creation_method The vegetation climate exposure analysis takes advantage of the 2015 vegetation map compiled for California by CALFIRE. Each Macrogroup (MG) was analyzed to determine which California habitats and associated dominant plant species make up its definition. California habitats are defined by the California Department of Fish and Wildlife (CDFW) through their California Wildlife Habitat Relationship (WHR) models9. WHR types are made up of plant species, such as the dominant trees, shrubs, and smaller plants. CDFW experts determined which WHR types correspond to each individual macrogroup; this cross-walk was used to develop a list of the dominant plant species that comprise each macrogroup. The climate space occupied by each distinct vegetation macrogroup (largely equivalent to a CWHR habitat type) from the current time period was identified. This was done by using the points for each type and applying a kernel density estimator on a 2-d surface composed of the first two principal components of the climate conditions. The result is a smoothed continuous point density surface, showing the prevalence of each vegetation type across the range of sampled climatic conditions. This surface was partitioned by fitting contour lines so that they enclose a proportion of the original points from the current time period. Contours were calculated at 5% increments. For example the innermost 5% contour line encloses the 5% of pixels for the given vegetation type which are at the core of the climate space for that type, as determined by its density in the climate space. Cells further away from the dense central core, are considered to be more marginal in the vegetation type's distribution. The outer contours are fit to enclose the 95-99% of climatically marginal points, with the last 1% of cells (beyond the 99% contour) being the most marginal. In addition, if a cell lies outside the space defined by the 99% contour of any vegetation type, it is considered to be "non-analog," which means that it experiences climatic conditions outside of the conditions where we have a good sample in the initial time period. Excluded from this assessment are non-vegetated types such as snow, open water, and ice; and non-natural landcover types mapped as vineyards, tilled earth, orchards and Urban. For more information on methods for the development of these climate refugia data see: Thorne et al. 2015 Thorne et al. 2016 Thorne et al. 2017 Thorne et al. 2020
data_units 0 1. Low values indicate higher resilience to threats. High values indicate significant exposure to climate change. 1 represents ‘non analog’ areas, i.e. locations that are outside the historic climate envelope of a given vegetation type.
data_vintage 1981 2010
element Disturbance
encoding utf8
file_name PotRefugiaBaseline_19812010_202401_T3_v5
format GeoTiff
harvest_object_id 21682f07-a77b-46ec-bfce-1a8bbb138e6b
harvest_source_id a2637971-af12-457f-ae4a-831d2202a539
harvest_source_title WIFIRE Commons
maximum_value 1.0
metric_definition_and_relevance This raster dataset represents habitat types (natural vegetation communities) and their distribution across the array of climate conditions that each separate habitat type is found in under the baseline climate conditions. A 2015 map of the state's natural vegetation compiled from multiple sources was classified to the National Vegetation Classification Standard's mid-level classification, called "Macrogroup". Thirty one natural vegetation macrogroups are identified in the map, covering 99.87% of the state's natural terrestrial vegetation, and occupying 353,271 km2. This serves as the foundation from which habitat types will be exposed to predicted changes in climate. Data are arrayed across 0 to 1 in terms of their exposure to current climate conditions. This data layer provides a baseline of vegetation adapted to "historic" conditions; i.e. climate conditions from the recent past; 1980-2010.
minimum_value -1.0
pillar Forest and Shrubland Resilience
spatial {"type": "Polygon", "coordinates": [[[-124.5121557327825, 32.42322653438314], [-113.49119142822133, 32.42322653438314], [-113.49119142822133, 42.11375096248461], [-124.5121557327825, 42.11375096248461], [-124.5121557327825, 32.42322653438314]]]}
tier 3