Discovering an ecological anomaly: Crowberry Bog

Joe Rocchio is a senior vegetation ecologist at the Department of Natural Resources.

It was a quiet August morning on the western Olympic peninsula. I was gearing up for another day of surveying for rare and high quality wetlands. In front of me was today’s mission—a 40-acre wetland.

The previous few days were challenging, consisting of difficult romps through dense, coastal swamp forests and I was not in the mood to repeat those adventures. As I stood on the edge of the wetland, finishing off my coffee and hoping the caffeine surge would get me over this lethargy, I looked toward the middle of the wetland and saw what looked like a thicket of tall shrubs. That meant another brutal day of bushwhacking. Ugh.

After a few minutes of hesitation, I took one last sip of coffee and jumped in. The first 20 meters were as expected—very mucky soils and slow going. At least there was no deep water and so far, the shrub density wasn’t too bad. The next 50 meters proved to be a bit drier but the shrubs were getting denser. And, those shrubs toward the middle were now looking like they would be over my head. Not looking forward to that.

After a few more minutes of plowing toward those tall shrubs, I came to an abrupt change in the vegetation. Waist-high shrubs all of a sudden dropped below my knees—same species, just dwarf versions of them. How could those tall shrubs I feared be so short? Their density also changed dramatically. They went from occupying all available space to being scattered. In between the dwarf shrubs was this continuous, fluffy, pillow-y, carpet of peat moss radiating beautiful shades of deep red, rusty orange, and lime green colors. These changes were not gradual—the transition was abrupt and clear.

This dwarf vegetation extended in front of me across a large, flat area. Trees changed too. In the area of dense shrubs, the scattered trees grew to 10-15 meters tall. But where the dwarf shrubs occurred the trees were short and looked like bonsai. The water levels had changed as well. The ground surface underneath the dense shrubs was moist but not wet.  However, when the dwarf shrubs appeared, I noticed that the water level was at the soil surface–the ground was saturated and squishy.

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Joe Rocchio shows a piece of peat moss, the organic material that makes up the majority of Crowberry Bog

As I looked back toward where I started, wondering what was going on, it hit me—no, floored me—I had just walked uphill. The area covered by scattered dwarf shrubs where I was now standing was higher than where I started. Okay, but why is the high point wetter than the slope leading up to it? Gravity doesn’t work this way. Water is supposed to move downhill, not uphill. Wetlands are supposed to occur where water collects in low points on the landscapes, not in places where water flows to the top of a hill. Where the heck was I?

Having spent a lot of time reading about the peatlands that occur in the high latitudes of Canada and Europe, and dreaming that one day I might be able to visit those boggy paradises, I started to piece together what I had just stumbled upon. It seemed I had just stepped into a raised bog—something that had never before been documented in the western United States. I felt like Indiana Jones finding the Ark of the Covenant.

I was by myself that day and didn’t have anybody to share this discovery with so I walked around the bog exuberantly talking to myself, “Dang, this is a raised bog. Right? Yes, it’s raised.”

Although I was blind to all the signs when I first walked into the bog, it was so obvious to me now.

“Look at how the edges slope DOWN toward the forest. The top of this bog is clearly above the edge. But, wait, raised bogs are not supposed to occur here. Well, here it is. True that. Wow, I just found a raised bog!”

I engaged Dr. David Cooper at Colorado State University to help design a research project that would provide the necessary information to determine whether Crowberry Bog was indeed a true, raised bog.  We installed 15 well nests across the site. At each nest are three to four groundwater wells that allow us to measure the water table, direction of water movement, and water chemistry.

crowberry wellnests
A DNR ecologist surveys one of the 15 “well nests” at Crowberry bog, tools used to measure the water table, direction of water movement, and water chemistry of the area.

If Crowberry Bog was a true, raised bog, it would have the following characteristics:  (1) The water table would be tightly associated with precipitation events; (2) the direction of water movement would be downward and lateral, at least in the winters months (if water movement was upward, that would indicate groundwater inputs); (3) the pH and calcium concentrations would be very low and less than found in local precipitation; and (4) vegetation patterns would show distinct zonation associated with these measures.

After a few years of data collection, it was apparent that Crowberry Bog indeed possessed all of these characteristics!  And, it is old. During our research, I found a scientific paper from 1974 that described a peat core collected from Crowberry Bog that showed the peat was about 5 m deep and started to accumulate nearly 16,000 years ago! Ancient and rare.

It has been eight years since that August morning and five years since I proposed that the site be designated a state Natural Area Preserve. Recently, the Board of Natural Resources voted to protect Crowberry Bog by transferring these lands into the Washington State Natural Areas program. The site is now permanently set aside for research, education, and, best of all, to conserve an incredibly beautiful and special place. I hope to help protect many other examples of Washington’s ecological treasures over the course of my career but if this happens to be the only place I’ve been successful, I will be content.