Research Projects Baldwin Hills Greenhouse Internship Program

By Stacey Vigallon, Director of Interpretation, and the Baldwin Hills Greenhouse Interns

On May 18, 2013 students participating in the Baldwin Hills Greenhouse Internship Program presented their research to the public at Baldwin Hills Scenic Overlook State Park. This year, projects addressed topics ranging from noise pollution and public safety to native plant germination rates. The information obtained through student research projects is sent to California State Parks and the Baldwin Hills Conservancy staff and is used to inform habitat restoration at the Baldwin Hills Scenic Overlook. We are extremely proud of the work that interns did during the 2012-2013 school year, and we’re looking forward to working with a new group of Greenhouse Interns and Restoration Leaders in the fall of 2013. Below we are pleased to present the 2012-2013 Greenhouse Intern project abstracts…

Diandra Dillon
The Effects of Noise Pollution at Baldwin Hills Scenic Overlook

IN1 sound level meter

Using a sound level meter to measure noise at Baldwin Hills Scenic Overlook State Park

Noise pollution is a harmful and irritating sound that affects birds and humans. I measured sound levels and recorded the number of birds and planes I heard at five different areas at the Baldwin Hills Scenic Overlook (BHSO). When noise level is too high humans may impact communication between birds. As a result of the noise level, bird species may eventually decrease because they are unable to communicate properly. As I predicted, the entrance of the park was the loudest of the five sites with an average sound level of 69.4 dB, likely due to constant vehicle traffic. My second hypothesis was also supported, in that I heard more birds and planes on average per survey at quieter sites, like the area behind the parking lot (3.7 birds, 2.6 planes) and the visitor center (2.9 birds, 2 planes). It was likely quiet at these sites because cars were rarely present and they have established native vegetation. My research is important because it provides baseline information about noise level at BHSO. Future projects could focus specifically on bird nesting in high and low noise level areas of the park.

German Soto
Illegal trails and Pedestrian Safety: How Are They Important to BHSO?

IN2 tape measure

Measuring the width of an illegal trail (made by park patrons and not an official part of the park trail network) at Baldwin Hills Scenic Overlook State Park

My project took place October 2012 through March 2013 and consisted of mapping and observing illegal trails around the Baldwin Hills Scenic Overlook State Park and observing pedestrian behavior at the park entrance. Before the crosswalk was completed, of the 91 crossing events observed 65% crossed Jefferson Blvd in one trip, while 35% paused in the median before completing the crossing. After the crosswalk was completed, I observed 268 crossing events: 97% of those occurred at the crosswalk in accordance with the walking signal. I mapped illegal trails at the park (12 total), and focused my observations on the illegal trail to the side of the stairs. I observed a total of 226 events in which a pedestrian would step off the stairs onto the illegal side trail: 32% of these events were while pedestrians were going up the stairs and 68% were while they were going down the stairs. Based on these observations, I recommend that rails be installed along the sides of the stairs to increase safety and preserve native vegetation.

Monica Anderson
What is the Relationship Between Bird Abundance and Human Abundance at the Baldwin Hills Scenic Overlook?

IN3 bird song collaboration

Collaborating with a program alumnus to create a song about bird conservation in Los Angeles

Baldwin Hills Scenic Overlook State Park (BHSO) is largely fragmented coastal sage scrub habitat, inhabited by approximately 166 bird species (Molina 2001), and surrounded by Los Angeles. From November 2011 to April 2012 and November 2012 to April 2013, I surveyed for bird and human abundance at BHSO, twice weekly between 1:30 and 5:30pm. I targeted five waypoints with a GPS, spending 4-30 minutes surveying birds and human activity within my survey points, using a field guide and binoculars. I hypothesized that bird abundance varied with human abundance and vegetation type at BHSO, and my data supported my hypothesis, but this year, the trend has become weaker. Within BHSO, bird abundance and species diversity were higher in sites with less human abundance and more established native vegetation. This year, bird and human abundance overall was lower than last year. At BHSO, I viewed 34 different bird species over both years. I added a music component to my project that tries to teach people about and engage people in the importance of habitat sensitivity and awareness; my music component rallied participants from Dorsey’s ecology club, and Leo Politi Elementary school students, and may have made the experience more memorable.

Miguel Gonzalez
When White Sage, Monkey Flower, California Buckwheat and Bush Sunflower are germinated and transplanted in the greenhouse, will they survive?

IN4 native seeds

Counting native plant seeds for a germination project

From December 2012 to February 2013, I measured and recorded the germination and survival rate for Bush sunflower (Encelia californica), California buckwheat (Eriogonum fasciculatum), White sage (Salvia apiana), and Monkey flower (Mimulus aurantiacus) inside the greenhouse at Baldwin Hills Scenic Overlook. After 12 weeks of conducting my experiment the four species I planted did not have the same survival rate, which was what I predicted. I planted 300 seeds of each species and after 56 days from seeding seedlings were transplanted to their own 4” pots. I counted the number of seedlings that survived after being transplanted and measured each twice a week, ending the experiment 51 days after transplanting. Out of 300 seeds, Bush Sunflower had the highest percentage of germination (20%), while Monkey Flower had the lowest percentage of germination (5%). White sage had the lowest transplant survival (15%) and Bush Sunflower again had the highest transplant survival (89%). Good follow-up experiments might be to use a different type of soil on the species that did not have such a great overall survival rate, like Monkey Flower, White Sage, and Buckwheat.

EJ Siufanua
The Effects of Roads and Trails on Wildlife Mortality at Baldwin Hills Scenic Overlook State Park

Baldwin Hills Scenic Overlook State Park is surrounded by a highly urbanized area, Inglewood, Culver City, and Los Angeles, California. The roads and the demand for building new trails may negatively affect wildlife at the park. November 2011 to April 2012 and November 2012 to April 2013, I surveyed roads and trails of the park for presence of roadkill from3:30-5:00 two days a week. I surveyed a portion of the main road and two different trails. I also counted pedestrians, cars, and bikes that were also using the same road and trails. I surveyed a trail next to the Greenhouse and one by the park’s Visitor’s Center. Contrary to my hypothesis, there was slightly more roadkill on the trails than on the main road. The roadkill mainly consisted entirely of invertebrates rather than vertebrates such as snails, bees, a grasshopper, pill bugs, a ladybug, and beetles. There were always a high number of dead snails on the main road and both trails.


Published Western Tanager Vol. 79 No. 6 July/August 2013