Data and Findings
The Los Angeles Parks Foundation conducted its second measuring day with staff from the Los Angeles Zoo's Conservation team on Saturday, Feb. 26th. The first measurement day was in September - another in late January was delayed due to the pandemic.
About ten volunteers and LAPF staff attended the workday. We began by weeding the entire "forest" of several varieties of invasive plants, including honeysuckle, mustard weed and grasses.
Once the weeds were removed, two things were noted:
The weeds did not cross the center, winding decomposed granite pathway and were confined almost exclusively to the northern side of the forest; The northern portion also achieved lower overall plant growth rates, which could possibly be attributed to the partial shade from over hanging mature trees. The southern half of the forest is in full sun.
All four types of plant material (understory, canopy, tree and shrub) showed healthy growth from the last measurement day in September.
LAPF is now working with students from the University of Southern California Masters in Landscape Architecture program to maintain the forest as well as the native plant nursery at our office.
Besides the Los Angeles Zoo conservation staff, many others have reached out to us about the Miyawaki method of afforestation, which was developed by Botanist Akira Miyawaki in Japan in the 1970s. Groups from as far away as Utah have called us soliciting information and advice about native forest installations.
Observations of Biodiversity: YEAR ONE
Biodiversity impacts have been huge. The forest attracted and supported numerous species of animals, including insects, reptiles, amphibians from the nearby LA River, birds, and small mammals. Ground squirrels burrows were utilized by western toads during the summer. Both ground squirrels and western fence lizards used the cover of the forest for nesting/reproduction, so not only has the forest provided food for these animals, it has provided a safe space for them to carry out their reproductive cycle, something missing from most conventional landscapes.
Insects and Arachnids:
Asian lady beetle, western aphideater, Jalisco petrophila moth, fiery skipper, western honey bee, southern green stink bug, three-lined potato beetle, four speckled hoverfly, aphids, grey bird grasshopper, foothill carpenter bee, katydid, pacific forktail, grey hairstreak, bagrada bug, flame skimmer, Fontana grasshopper, small white butterfly, robber fly, Carolina sphinx moth, European paper wasp, bee fly, jumping spider, Mediterranean red bug, western spotted orbweaver, Toltec scoliid wasp, ants, banded bee fly, sweat bee, ichneumonid wasp
yellow-rumped warbler, bushtit, black phoebe, mourning dove, dark eyed junco, California towhee, American robin, anna’s hummingbird
western fence lizard, western toad
ground squirrel, eastern fox squirrel
Parts of the micro forest underwent a natural period of summer dormancy during 2022. Summer dormancy is a drought-triggered adaptation of many native species which enable them to survive without water or care during the hottest time of the year. Species which went summer-dormant (or drought-deciduous) were: blue elderberry, creeping snowberry, CA rose, and heartleaf keckiella. Species which retained an evergreen appearance were: toyon, lemonadeberry, coast live oak, coffeeberry, and hollyleaf redberry. Currently (as of November 2022), many summer dormant species are already resprouting after having been triggered by the cooler weather and recent light rains.
First year takeaways:
Biodiversity Impacts: Forest attracted and supported numerous species of animals, including insects, reptiles, amphibians from the nearby LA River, birds, and small mammals. Ground squirrels burrows were utilized by western toads during the summer. Both ground squirrels and western fence lizards used the cover of the forest for nesting/reproduction.