Spontaneous urban flora of Los Angeles: Transect data

The city of Los Angeles comprises nearly 500 square miles and supports
nearly four million people who reside on lands that were once composed of
a diverse mosaic of wetland and upland plant community associations. On
top of these historic vegetation layers are socioeconomic legacies of a
redlining grading system for the city established by the Federal Housing
Administration's Home Owners Loan Corporation (HOLC). Throughout
neighborhoods in public parkways, the spaces between property bounds and
the road, reside an often overlooked spontaneous and self-propagating
community of native and introduced taxa. With an interest in documenting
this flora at a time of rapid environmental and socioeconomic change in
the city, I performed a series of floristic checklists for nearly 400
blocks comprising nearly 50 total miles at sixteen neighborhoods
throughout the city between the end of January and middle of March 2021.
Transects were walked within specific neighborhood communities chosen to
represent all four HOLC codes and a combination of historic wetland and
upland vegetative communities. Across all transects and sites, I found a
total of 168 spontaneous self-propagating plant taxa, and a significant
effect of historical plant community (upland, wetland) on plant species
richness and phylogenetic diversity but not HOLC code. I also present and
discuss patterns of community similarity and turnover between sites. This
dataset of plant species presence by block, and the list of transect
locations, is publicly available via dataDryad so that it may serve as a
point of reference for future studies of urban ethnobiology.