Late Seral Stage Distribution

The seral stages are categories that represent the developmental progression of forest ecosystems from initial establishment or following a stand replacing event (e.g., high severity fire) to a forest dominated by trees in the upper age classes for a given forest type. Late seral forests are also often characterized by multiple ages of forest trees and dead and dying trees in some form of equilibrium. Seral conditions across landscapes were highly variable prior to major European settlement in the western US. These patterns were highly attuned to dominant disturbance regimes and the multi-scaled variability in environmental conditions across topographic and climatic gradients. These patterns helped to reinforce fire regimes dominated by low- to moderate-severity fire across much of the region and provided for multiple habitat requirements for a wide variety of species.

This metric contains three related data layers. The first is an assignment to each 30 meter pixel of the seral stage it is currently in, either early, mid, or late seral stage (SeralStage_EML_202304.tif). The other two layers (EarlySeralStageDist_202304_202406_T1_v5.tif; LateSeralStageDistr_202304_202406_T1_v5.tif) represent the proportion of a HUC 12 watershed that is in 1) early seral stage or 2) late seral stage.

Data and Resources

Additional Info

Field Value
Version Version 5.0
Last Updated March 28, 2025, 08:35 (UTC)
Created March 7, 2025, 07:51 (UTC)
category /Forest and Shrubland Resilience/Composition
collection_name California Landscape Metrics
creation_method The FVEG data, used in characterizing vegetation and habitat conditions for a number of metrics in this kit, contain data on tree size (see FVEG discussion above). Seral stages for forested lands are binned into one of three categories of tree size (Early, Mid, Late) and those are defined by tree diameter, per the CWHR system. **Size Class** | **Size (inches DBH)** | **Seral Stage** ---|---|--- 1 Seedling | less than 1 | Early (1) 2 Sapling | 1 '€“ 6 | Early (1) 3 Pole | 6 '€“ 11 | Mid (2) 4 Small | 11 '€“ 24 | Mid (2) 5 Medium to Large | 24+ | Late (3) 6 Multi-storied | 36 '€“ 48 | Late (3) Late Seral conditions have been lumped into a single classification (24" and up). The first layer provided here assigns a early, mid, or late seral value to each cell based on dominant tree size in the canopy. Null or NoData values in this raster represent areas of non-forest. The second and third data layer provided identify the proportion of the HUC12-scale (typically 10,000-30,000 acres in size) that is either early seral forest or late seral forest, respectively. These patterns can be highly variable at finer-scales so we used a HUC 12 watershed as the unit for expressing relative abundance. For each HUC12, the proportion of the watershed covered by the evaluated seral stage has been calculated.
data_units Seral Stage: Categorical 1 - 3. Early or Late Stage: continuous variable 0-1 representing percentage of a HUC.
data_vintage 04/2023
date_updated August 2024
element Composition
encoding utf8
file_name LateSeralStageDistr_202304_202406_T1_v5
format GeoTiff
harvest_object_id dea343e2-af9d-462b-a699-296b809afc74
harvest_source_id a2637971-af12-457f-ae4a-831d2202a539
harvest_source_title WIFIRE Commons
maximum_value 0.9
metric_definition_and_relevance The seral stages are categories that represent the developmental progression of forest ecosystems from initial establishment or following a stand replacing event (e.g., high severity fire) to a forest dominated by trees in the upper age classes for a given forest type. Late seral forests are also often characterized by multiple ages of forest trees and dead and dying trees in some form of equilibrium. Seral conditions across landscapes were highly variable prior to major European settlement in the western US. These patterns were highly attuned to dominant disturbance regimes and the multi-scaled variability in environmental conditions across topographic and climatic gradients. These patterns helped to reinforce fire regimes dominated by low- to moderate-severity fire across much of the region and provided for multiple habitat requirements for a wide variety of species. This metric contains three related data layers. The first is an assignment to each 30 meter pixel of the seral stage it is currently in, either early, mid, or late seral stage (SeralStage_EML_202304.tif). The other two layers (EarlySeralStageDist_202304_202406_T1_v5.tif; LateSeralStageDistr_202304_202406_T1_v5.tif) represent the proportion of a HUC 12 watershed that is in 1) early seral stage or 2) late seral stage.
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