Annual biomass data (2001-2023) for southern California: above- and below-ground, standing dead, and litter

Biomass estimates for shrubland-dominated ecosystems in southern
California have, to date, been limited to national or statewide efforts
which can underestimate the amount of biomass; are limited to one-time
snapshots; or estimate aboveground live biomass only. We developed a
consistent, repeatable method to assess four vegetative biomass pools from
2001-2023 for our southern California study area (totaling 6,441,208 ha),
defined by the Level IV Ecoregions (Bailey 2016) that intersect with USDA
Forest Service lands (Figure 1). We first generated aboveground live
biomass estimates (Schrader-Patton and Underwood 2021), and then
calculated belowground, standing dead, and litter biomass pools using
field data in the peer-reviewed literature (Schrader-Patton et al. 2022)
(Figure 2). Over half (52.3%) of the study area is shrubland, and our
method accounts for three post-fire shrub regeneration strategies:
obligate resprouting, obligate seeding, and facultative seeding shrubs. We
also generate biomass estimates for trees and herbs, giving a total of
five life form/life history types. These data provide an important
contribution to the management of shrubland-dominated ecosystems to assess
the impacts of wildfire and management activities, such as fuel management
and restoration, and for monitoring carbon storage over the long term. The
biomass data are a key input into the online web mapping tool SoCal
EcoServe, developed for US Department of Agriculture Forest Service
resource managers to help evaluate and assess the impacts of wildfire on a
suite of ecosystem services including carbon storage. The tool is
available at https://manzanita.forestry.oregonstate.edu/ecoservices/ and
described in Underwood et al. (2022). REFERENCES Bailey, R.G. 2016.
Bailey's ecoregions and subregions of the United States, Puerto Rico,
and the U.S. Virgin Islands. Forest Service Research Data Archive. (Fort
Collins, Colorado). https://doi.org/10.2737/RDS-2016-0003 Schrader-Patton,
C.C. and E.C. Underwood. 2021. New biomass estimates for
chaparral-dominated southern California landscapes. Remote Sensing, 13,
1581. https://doi.org/10.3390/rs13081581 Schrader-Patton et al. 2022.
“Estimating Wildfire Impacts on the Biomass of Southern California’s
Chaparral Shrublands.” Proceedings for the Fire and Climate Conference May
23-27, 2022, Pasadena, California, USA and June 6-10, 2022, Melbourne,
Australia. Published by the International Association of Wildland Fire,
Missoula, Montana, USA. Underwood et al. 2022. “Estimating the Impacts of
Wildfire on Chaparral Shrublands in Southern California using an Online
Web Mapping Tool.” Proceedings for the Fire and Climate Conference May
23-27, 2022, Pasadena, California, USA and June 6-10, 2022, Melbourne,
Australia. Published by the International Association of Wildland Fire,
Missoula, Montana, USA.