Students at work on the hillside adjacent to the greenhouse at Baldwin Hills Scenic Overlook.

By Stacey Vigallon and Baldwin Hills Greenhouse Program Interns

On May 19, 2019, the Baldwin Hills Greenhouse Program wrapped up its 11th school year. Greenhouse Interns collectively invest hundreds of hours in the research process: crafting a proposal, collecting and analyzing data, designing a research poster, and presenting their work to the public. Each year, we publish the research abstracts in an effort to share the knowledge gained with a broader audience and to acknowledge the interns’ hard work and commitment. This year’s projects include both qualitative and quantitative approaches to better understanding humans and nature in our city.

Natan Euol

Documenting Mammal Activity at Baldwin Hills Scenic Overlook State Park

My project involved mapping mammal activity at Baldwin Hills Scenic Overlook State Park (BHSO). From November 2018 until April 2019, I collected and analyzed observations from surveys along with multiple camera trap placements around BHSO. The results accumulated from both sources of data were categorized by mammal species and the context behind how their presence was noticed, which was visual sightings, scat, tracks, or camera trap images. A total of 10 mammal species were detected. My hypothesis that I would observe signs of mammal presence more often than I would observe mammals themselves was made evident by my data: I directly observed only 4 species but captured by camera or observed signs of 8 species. Due to human activity within these areas, I originally hypothesized that I would not observe signs of mammals on park trails and roads; however, I did observe tracks, scat, and mammals themselves on these high-use human trails. The importance of my project lies in its potential to show the effects of human activity on mammals at BHSO.

Images from Natan’s camera traps to detect mammals at Baldwin Hills Scenic Overlook

Savannah House

The Germination and Transplant Survival Rate of Native Plants in Potting Soil versus Site-Specific Soil

The Baldwin Hills Scenic Overlook is an important area to restore because native habitats are important to the ecology of the area and to human beings, psychologically and physically. My research tested the germination rates of California Black Walnuts, White Sage, Toyon, Bladder Pod, and Deer Grass in site-specific versus potting soil, as well as the transplant survival rate of the California Black Walnuts germinated in either soil type last year (2017-2018). I hypothesized that native plants would germinate equally well in site-specific and potting soil, however Deer Grass, Toyon, and White Sage all had a somewhat higher germination rate in potting soil (9%, 55%, 4% respectively) than in site-specific soil (8%, 23%, 2% respectively). Deer Grass germinated in site-specific soil had a higher survival rate. Rodent activity impeded completion of California Black Walnut and Bladder Pod germination experiments. I also predicted that walnut saplings germinated in site-specific soil would have a higher transplant survival rate, given that they were germinated in the same soil type. However, there was a 100% survival rate for both soil types. Future research should focus on transplanting the germinated native plants as well as deterring rodents from Bladder Pods and California Black Walnuts.

Mohamad Lorenzano

Perceptions of Park Safety

Access to parks and nature is important for both physical and mental wellness of communities. I formulated a 17-question survey revolving around the perception of park safety during the fall 2018 semester and administered the surveys to four groups of individuals over the spring 2019 semester. These four groups were Culver City High School students, Dorsey High School students, Greenhouse Program students (Culver and Dorsey students distinct from those in the previous groups), and adult employees at one of my other internship sites. My hypothesis that there would be no difference in answers between genders was mainly supported by my data. Although I also predicted that high school students go to parks more frequently than adults, there was also no notable disparity between the frequencies of visitation among the age groups. However, the contrast of respondent perceptions between the two high schools was notable: Dorsey students consistently indicated that they felt parks in LA were unsafe, while Culver City students had considerably more positive perceptions about park safety. This finding has implications for public health and access to resources.

Axel Maya

Comparing Compost Bin Types for Invasive Plant Composting

From January to March 2019, I initiated the first year of an invasive plant composting project at Baldwin Hills Scenic Overlook State Park. Knowing an effective method for composting leaves a smaller carbon footprint and gives you another way of eliminating invasive species. I compared 3 types of compost bins (trashcan, open wire, and pallet box), using the same mixture of invasive grass for all of them. My hypothesis that the trashcan compost would take less time was wrong at this initial stage of the project. The compost height for all three types of bins was reduced to 1/3 of its original height at the start of the project. At this point, the type of compost bins did not have a major difference on the height of the compost. Compared to the other two bins, the trashcan compost had a strong smell within the first few weeks that eventually went away. The trashcan compost also felt moist and hotter compared to the other bins. This is a 2-year project: next year, I will compare the compost more in depth, in terms of quality of decomposition and invertebrates present.

Axel constructed three different types of compost bins to test decomposition of non-native plants.

Brandon Kim

Analysis of Nature Interpretations Based on Student Literary Samples

Human modification of the environment has led to a significant human-nature disconnect; my project investigates this disconnect by examining different interpretations of nature and thus its impacts on people living in an increasingly urbanized world. These interpretations were collected in the form of literary samples created (1) by students mainly in the Baldwin Hills Greenhouse Program; (2) my own responses to personal nature-related prompts, and (3) samples gathered during an all-ages youth summit event. The most important samples were six-word stories and an emotional reflection on nature. Though differing in certain respects, common trends mostly did emerge from these samples, helping to show people’s level of exposure to and disconnect with nature. One trend was a view of nature as an escape from a stressful urban environment, which suggests humans have become severely entrenched in urban environments and have little exposure to nature. Nature was also found to have psychological benefits by way of its emotionally calming effect and the reflective, introspective mindset it induced in students. Knowledge of these benefits and disconnect from nature can aid in people’s management of their urban lives and how frequently they decide to spend time in natural spaces.

Julia Adler

Mapping Toyon and Cacti at Baldwin Hills Scenic Overlook

The fire cycle, a natural process that has been altered by urbanization and climate change, is an integral part of natural habitats. Many native plants in Southern California have developed adaptations and even a reliance upon fire. Even with this tolerance, more frequent and intense fires can cause a proliferation of invasive grasses and nonnative plants. For my project I mapped two native species, Toyon and Prickly Pear Cacti, at Baldwin Hills Scenic Overlook to document their presence and distribution. In the event of a fire, these maps can help make restoration more efficient. The majority of Toyon clusters were found on north-facing slopes, which was consistent with my hypothesis. However, some clusters were found close to the stairs or to paths, possibly for recreational landscaping reasons. Cacti, on the other hand, were found mostly within 5 meters of a trail, and absent from the north-facing slope, which aligned with my hypothesis as well. Cacti were planted in some areas to keep people from deviating from the path.

Ahmad Rizwan

Bird and Trash Presence at Baldwin Hills Scenic Overlook & Ballona Creek

It is crucial to acknowledge the ecological importance of Baldwin Hills Scenic Overlook (BHSO) for native wildlife. I predicted that there would be more plastic trash than paper trash present along my Ballona Creek survey route, and the number and types of birds would be different along Ballona Creek than at BHSO. Supporting my hypothesis, I observed, on average, more species and individual birds at BHSO (18 species detected; 9.1 individuals per survey) than along my Ballona Creek survey route (8 species detected; 3.5 individuals per survey). I found that both types of trash were present at both BHSO and Ballona Creek; but, I did not count individual pieces of trash. For this reason, I could not conclude whether or not plastic was more prevalent than paper trash in these areas. Thus, for future research, I would recommend using a survey strategy to count individual pieces and types of trash present in BHSO and Ballona. In addition, I would also observe how birds react to various types of trash at BHSO and Ballona Creek, because observing their behavior with trash could indicate the dangers urbanization imposes on the natural environment.

Ahmad conducts a bird survey at Baldwin Hills Scenic Overlook.

John Recendez

First Steps for a Greenhouse Business Plan

My long-term project is a business plan focused on selling plants to the public at the Baldwin Hills Greenhouse Program. The purpose behind it is to help educate the community on the importance of native plants and their impact on the native ecology. The majority of my time this year was spent conducting marketing research and organizing the things to expect in the future of working on this project. The research was primarily a survey given to all Greenhouse Program students that asked about their living situation, things relating to their families’ relationship with native plants, and how their outdoor garden spaces were managed. This information helped to understand my future customers and helped me plan my next steps. The business should focus more on informing people rather than advertising. The next steps in my project will be to contact California State Parks about tax issues, research California taxation laws to implement into the business plan, and formulate the base of the business plan itself.

Samuel De Riseis

The Effect of Three Root Stimulant Treatments on Elderberry and Laurel Sumac Cuttings

Seed germination rates for some native plants tend to be low; hence, for restoration purposes, it may be worth attempting to propagate some species through cuttings. My project concerns optimizing this process - propagation via cuttings - by treating Laurel Sumac and Elderberry cuttings with either willow water, chemical rooting stimulant, or honey water. I hypothesized that there would be no difference in root presence between Laurel Sumac and Elderberry cuttings and between the different treatment groups. Contrary to my hypothesis, the Elderberry control group (no treatment applied) produced roots more than did the other groups (42.8%), possibly because the control replicated the natural soil chemistry the Elderberry is accustomed to. Future propagation of Elderberry cuttings can therefore be chemical-free. Both honey treatment groups did not root (Elderberry) or display new growth (Laurel Sumac), possibly because the concentration of honey in the solution was too high, promoting bacterial and mold growth and rotting the cutting. I recommend further testing with a honey solution of lower concentration and a larger sample to affirm or reject my findings.

Laurel sumac and elderberry cuttings in the greenhouse as part of Sam’s research project.

Aaron Rivas

Irrigation Systems and Native Plant Survival

Due to Los Angeles’s Mediterranean climate and our state’s frequent droughts, irrigation systems have become a necessity for plants that do not receive adequate water, including the many native plants being restored as habitat for animal species at the Baldwin Hills Scenic Overlook (BHSO). For my project, I divided the traffic circle at the entrance to the BHSO into two sections, one with drip irrigation and one with ring irrigation. Native plants were added into both these systems to test my hypothesis that drip irrigation would result in a higher survival rate of native plants than would ring irrigation. A staff member, fellow Greenhouse Program students, and I finished installing both irrigation systems and planted all the native plants on March 8, 2019. This project developed into a 2-year project due to high rainfall during the winter. Staff will use the irrigation system from the summer through fall of 2019, and then I will collect data on plant survival once the next school year starts to test my hypothesis.

This article was first published in the July/August 2019 Western Tanager, Vol. 85 No. 6.