Corvallis High School Ecology and Classroom Without Walls measured flora biodiversity and water quality at Roaring Lion on Monday.

The class has measured the progress since the 2016 fire.

Ecology educator Tracy Dickerson said she’s pleased with the changes.

“The increase in biodiversity in just three years is really amazing,” she said.

The blackened snags still are the main feature of this once lush forest but the roaring creek, singing birds and low growth greenery on the forest floor give hope.

The student groups marked off their testing areas that were exactly located by latitude and longitude directions from previous years.

They measured both species richness and diversity.

Species richness is a count of the different types of plants, while species diversity takes into account the relative abundance (quantities and evenness) of each species.

“Basically, what they are doing is taking a species richness is how many different species there are and a species diversity is taking into account the relative abundance of each one,” Dickerson said.

“Students are counting each stem as close as they can, there is so much more than the first year. The richness value continues to go up at a rate of approximately 10 species per year post fire, and the evenness is conducive of a healthy growing ecosystem.”

The species found in the plot with students Olivia French, Madeline DeLeo, Ethan Gager, Izzie Devine and Ciara Chavez included Rocky Mountain Maple, fireweed, white spirea, nine bark, snow berry, blue eyed mary, buffalo berry, Oregon grade, pine grass, heart leaf arnica and a woodland violet,

Dickerson explained that many of those species are the first to grow after a fire.

“You want a nice even diversity,” Dickerson said. “For example, if there are four different species it is nice to have them in equal numbers for biodiversity rather than one species taking over.”

Though not in a plot she has also seen lots of wildflowers — lupine, heart leafed arnica and wild rose — cottonwood trees growing on the trail and seedlings of ponderosa pine and Douglas fir.

Overall Dickerson said Roaring Lion area is “coming along nicely.”

“There is now more growth than happened after the fire near Pinesdale,” she said. “That took a lot longer to come back.”

Overhead a drone, piloted by Jaiden Walker of the Classroom Without Walls class, took “wave point” pictures at several angles and Birdseye views from the top of each plot.

“It is really neat because we can see and we can visualize the differences from year to year,” Dickerson said. “I showed them pictures of the first year where it was just black soil and it is definitely different now.”

CHS students also tested the water quality of Roaring Lion Creek.

“Sediment levels are low, even for this time of year during spring run-off, pH, nitrogen, and phosphorus levels are normal, and dissolved oxygen levels are high,” Dickerson said. “All of this is very good.”

Students will measure the soil nutrient levels on Friday.

“The results are unknown exactly at this time; however, the fact that the flora community is growing so strong is indicative of healthy soil,” Dickerson said.

Most of the students hadn’t hiked Roaring Lion before the fires but have seen photographs of the forest before the fire, then of each year since. They agreed that the forest is improving.

“There are so many plants and great biodiversity,” student Olivia French said. “There is a lot of good growth.”