Risk of Tree Dieoff During Drought

A quantitative continuous variable that reflects the risk of tree dieoff during a significant drought period (SPI48 drought = -2).

Data and Resources

Additional Info

Field Value
Version Version 5.0
Last Updated March 28, 2025, 08:36 (UTC)
Created March 7, 2025, 07:52 (UTC)
category /Forest and Shrubland Resilience/Disturbance
collection_name California Landscape Metrics
creation_method Calculated by combining information on the local moisture balance and tree density. Local moisture balance was calculated as the ratio of Annual Evapotranspiration with the canopy observed in 2021 to Precipitation during a SPI 48 drought = -2 based on local P observations during 1991-2020. This ratio quantifies the local moisture deficit/surplus that would be expected during a 48-month period with precipitation that is 2 standard deviations below the local 30 year Normal. Tree cover was determined from Landsat. **** See https://doi.org/10.1038/s41561-019-0388-5 for further information.
data_units This is a dimensionless index that ranges from 0 to ~20000. Low values indicate minimal or no risk of tree dieoff during drought, either or both because there are few trees in the pixel and/or there is ample local moisture even during periods of extreme precipitation shortfall. High values indicate significant risk of tree dieoff during drought, as a result of both a high density of trees at the site and likelihood of extreme local moisture shortfall.
data_vintage 12/2021
date_updated August 2024
element Disturbance
encoding utf8
file_name RiskTreeDieoff_202112_202312_T1_v5
format GeoTiff
harvest_object_id c34d94a9-a840-4839-870d-1c9b0e88adf8
harvest_source_id a2637971-af12-457f-ae4a-831d2202a539
harvest_source_title WIFIRE Commons
maximum_value 20000.0
metric_definition_and_relevance A quantitative continuous variable that reflects the risk of tree dieoff during a significant drought period (SPI48 drought = -2).
minimum_value 0.0
pillar Forest and Shrubland Resilience
spatial {"type": "Polygon", "coordinates": [[[-124.5090833859125, 32.4242698701859], [-113.49380570277376, 32.4242698701859], [-113.49380570277376, 42.1119747450123], [-124.5090833859125, 42.1119747450123], [-124.5090833859125, 32.4242698701859]]]}
tier 1