Camas on Campus

The Rock Creek Environmental Science Center (RCESC) at Portland Community College maintains a large natural area including "upland coniferous forest (26 acres), bottomland forest (7 acres), oak woodland (3 acres), emergent and shrub scrub wetlands (30 acres), and wet prairies formerly used for grazing (12 acres)" (Brenneis et al. 2022). These habitats are uniquely situated between the Portland urban growth boundary and agricultural land.

The Willamette Valley was once decorated with carefully maintained oak woodlands and wetland prairies that flooded seasonally. This picturesque landscape was cared for by the many tribes with villages along the Columbia River. One of the tribes known to occupy the land that PCC Rock Creek Campus now exists on was the Tualatin Kalapuya.

The wetland prairie habitats on campus are mostly overgrown with pasture grasses after grazing has ceased. However, scattered among the tall grass during spring one can spot single stemmed clusters of purplish blue flowers. This species of flower has a special history and connection to this land.

The white to purple-blue flowing bulb plant known as camas has long existed within the Willamette Valley and for many years was a central point for Kalapuyan culture. Their civilization had developed a schedule moving between camps specialized for certain tasks best performed at certain times of the year (Lewis 2022). An important guiding factor to this thoughtfully arranged calendar was the annual growing patterns of camas.

The Kalapuyan people made sure to tend to the seed cycles of the camas, likely collecting and spreading seeds to encourage more camas growth and potentially controlling where the camas fields were (Lewis 2022). Once bulbs were large enough for harvest, they would collect them and start the multi day cooking process (Lewis 2022). There is reason to believe that camas processing occurred more than once a year and at different campsites alongside different seasonal tasks (Lewis 2022). The importance of the small flowering bulb plant to their diet, culture, and society is clear.

 Within the wetland prairie in the RCESC are patches of camas bulbs. The presence of this flower allows the PCC RCESC to create an opportunity for reintroducing indigenous stewardship of camas and the land around campus. In order to safely facilitate this, the RCESC has applied for and been awarded a grant to test the soil and camas bulbs on campus for potentially harmful levels of heavy metals and herbicides. Students helped to draft this grant as well as collect samples in the field and get them to Pacific Agricultural Laboratory and Apex Laboratories LLC for testing.

Two fields have been identified by Valance Brenneis as being dense with camas and ideal for sampling efforts.

Valance Brenneis worked with students in the ESR 204 Environmental Restoration class to develop a plan for random sampling of the soil. Soil collection kits were picked up from two different labratories: Pacific Agricultural Laboratory and Apex Laboratories LLC.

The first team of students measured the two fields into grids in order to facilitate random sampling of the soil. For the eastern camas field a border was outlined 75m east to west, 10m north to south. Orange flags were placed every 3m on the E-W edge, and every 5m on the N-S edge. This split the area into a grid of 50 rectangles. The western camas field was outlined with 35m going east to west and 15m going north to south. Flags placed along the E-W edge placed every 3.5m and flags placed along the N-S edge placed every 3m. This created another grid of 50 rectangles.

The groups of students responsible for sampling split each of the individual 50 rectangles down into a smaller grid before using a random number generator to determine the area of that grid in which to sample across the entire field. The eastern field was done using a triplicate sample, meaning that three teams used that number generator once and sampled across the entire field. In the end the three samples of soil from the eastern field were combined for testing. The western field was smaller and only sampled with one team and one pass through.

A separate team of students was responsible for identifying and flagging camas to help prevent sampling teams from trampling plants. This was done while the sampling site was measured out and it was predetermined that we would collect camas samples at the end favoring the ones that had been trampled or damaged by students in the area. This helped us to leave as many camas plants in tact as possible while still being able to collect the 100 grams of camas needed. Plants were weighed in the field to ensure this was met.

While measuring out the boundary of the camas field to be sampled, GPS points were placed using the Gaia GPS app at each corner. These GPS points acted as a guide for creating a polygon feature class in ArcPro to represent the study site. This feature class was shared to AGOL as a web layer to be used in the AGOL wep mapping platform.

The team responsible for flagging camas and collecting samples also collected GPS referenced data on the camas found at each site. This team used iNaturalist to create a GPS point with associated data on the site size, the amount of camas present, the species of camas identified on site, and a collection of photos. This information is displayed in pop-ups on the results dashboard camas fields map.

Awareness of contaminants in gardening soil is becoming more prevelant. Plants intended for consumption could be taking up these contaminants when grown in unsafe soils. This topic is increasingly important as urban gardening and farming becomes more necessary in dense urban communities.

We tested to determine the levels of heavy metals, legacy chemicals, and herbicides. Some of the materials being tested for have no safe limit meaning that any trace amount present in food could be extremely detrimental to human health. Others may have much larger ranges of what is considered safe for consumption or exposure at different levels. The following list is what the tests performed by Pacific Agricultural Laboratory and Apex Laboratories LLC focused on.

• Arsenic
• Barium
• Cadmium
• Chromium
• Lead
• Mercury
• Selenium
• Silver
• Glyphosate
• Imazapyr
• Triclopyr

Background concentrations of metals refers to the naturally occuring levels of these materials already present in the soil. When test results give us levels that are less than or equal to the background levels we can assume that our soils are likely not impacted by a significant pollutant. The three different screening levels determined by the OHA include Oregon DEQ background estimates and residential screening level, as well as a third screening level focused on public health. The third screening level is important for contaminants like lead that have no safe amount for human consumption. Their intention is for individuals to compare results to each level. For our herbicide results the limit of quantity is listed within the data table to more directly compare the results. Learn more about the OHA's recommendations on soil testing and healthy gardening soils by clicking the button below.

We can see from Table 1 that our test results for arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver are all well below any noted heavy metal background levels in our area. The standard deviation between values is also very low indicating that our results are likely representative of the larger wetland prairie habitat in RCESC.

The herbicide results are especially exciting as there was nothing detected for all three herbicides in either the soil or camas plant samples.

There is a history of applying herbicides on a number of invasive plant species around campus. Confirming that these herbicides are not longer lingering in the soil or plants, especially in the wetland prairie habitat, is crucial for us making a determination on the health and safety of handling or consuming these plants from campus.

The results dashboard was completed to display the results of the testing and provide background context for the testing. The dashboard bar graphs provide a mean value for the results between both fields. The values for each field's test results can be seen in pop-ups when you select them.

This survey was put together using Survey123 and framed around the data collected during this project. This survey is focused on camas and aims at collecting GPS data, photos of camas observations, data on the amount of camas observed, and identifying the particular species of camas observed.

If you find yourself in the RCESC and spot some camas use the link below to download Survey123 or open Survey123 on a web browser and complete the Camas Survey!

The goal of this survey is to help compile data on camas found throughout RCESC to better inform future camas sampling efforts. Submitting a survey requires a cellphone with accurate gps data and the ability to take a photo. Multiple submissions can be made by one user.

Special thanks to Val Brenneis for facilitating this opportunity for students and for providing me with the data!

Brenneis, V., Swanson, J. Liebeseller, L., Moseley, M., Smith, M., Krige, R. 2022. Screening for contaminants in soil and camas bulbs to ensure safety of the Rock Creek Environmental Studies Center wet prairie as a site for cultural use by Indigenous partners. TSWCD Tualatin Watershed Improvement Grant proposal. Portland Community College, Portland, OR.

Johnson, Tiffany. 2018. Background Levels of Metals in Soils for Cleanups. Oregon Department of Environmental Quality. OR.  https://www.oregon.gov/deq/FilterDocs/cu-bkgrmetals.pdf 

Lewis, David G. 2022 April 27. Week 4 guest lecture. Presented at: ESR 204. Portland Community College.

OHA. 2016. Healthy Soils: Information about testing your yard or garden. Oregon Heath Authority, Public Health Division. OR.  https://sharedsystems.dhsoha.state.or.us/DHSForms/Served/le9745.pdf 

Stevens, M., D.C. Darris, and S.M. Lambert. 2000. Plant guide for common camas (Camassia quamash ssp. breviflora). USDA-Natural Resources Conservation Service, National Plant Data Center, Greensboro, NC, and Corvallis Plant Materials Center, Corvallis, OR.  https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/orpmcpg13212.pdf 

Stevens, M., and D.C. Darris. 1999. Plant guide for great camas (Camassia leichtlinii ssp. suksdorfii). USDA-Natural Resources Conservation Service, National Plant Data Center, Greensboro, NC, and Corvallis Plant Materials Center, Corvallis, OR.  https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/orpmcpg13213.pdf 

University of Washington. 2021. “UW Scientist Tests Soil for Hidden Contaminants in Community Gardens.” YouTube.  https://www.youtube.com/watch?v=tyx23cy_WSA .