The western side of Olympic National Park is dominated by a temperate rainforest. There are two rainforests: Quinault to the south, and Hoh to the north (which we visited).
The Olympic rainforest receives 150-200 inches of precipitation per year, making it the wettest area in the continental United States (the Hawaiian island of Kauai receives even more rain). In stark contrast, the area in the Olympic rain shield just 30 miles east receives only 15 inches of precipitation per year. As the moist Pacific air comes onshore, it rises up the Olympic Mountains and drops most of its precipitation on the western side of the mountain, creating a rainforest to the west and a semi-arid forest to the east.
Unlike tropical rainforests or even most temperate rainforests, the Olympic rainforest is dominated by coniferous trees such as the Sitka Spruce, Western Hemlock, Douglas Fir, and Western Redcedar. Much of the area is old growth forest with cedar trees that can reach up to 300 feet tall. Unfortunately I don’t know my tree bark well enough to tell you what kind of dead tree this is, but it’s still standing tall.
Mosses coat the bark of many trees and hang down like drapery. We had to laugh when one man asked the park ranger, “When’s the best time of year to come when there’s more moss?” True it was dry and not very lush when we visited at the end of their typical dry season in September, but the moss was everywhere!
We saw these black slugs before in Yoho National Park. These slimy slugs are 2-3” long and covered in a foul-tasting mucus (though we didn’t actually lick a slug to confirm).
It seems counterintuitive, but trees have a very rough time growing in this rainforest. Turns out the rainforest floor is so crowded with ferns and other plants that baby trees cannot get enough sunlight to take root. So their elders come to the rescue. Fallen trees provide a much needed “step up” above the groundcover for young trees to start their life. These fallen trees are called “nurse logs,” and you’ll often see trees growing in a straight line atop a nurse log. Sometimes the nurse log erodes away, leaving a line of trees that look like they were deliberately planted in a row by humans but weren’t.
We liked how the park service got creative by routing the hiking trail between these fallen trees. Here I am doing the splits between two fallen giants.
The beautiful glacier-fed Hoh River was a welcome companion on our hike through the rainforest.
We passed this caravan of llamas carrying supplies for climbers.
Epiphytes are plants growing on other plants. Moss typically does not harm its tree host. Unlike a parasite, instead of getting its nutrients from the tree, moss gleans everything it needs to live from the air and rainwater. However, if a tree is weakened from other causes, wet moss can add enough weight to the tree that it may bend or break in a windstorm.
This provides a nice snapshot of what it’s like on the floor of a temperate rainforest: lots of ferns, clover and other leafy plants; downed trees that serve as platforms for other growth; and plenty of moss and mushrooms. I thought it was interesting that this one log was host for three different types of mushrooms.
There’s an old saying that “Beauty is on the eye of the beholder,” or something like that.
The highlight of our visit to the rainforest was the Hall of Mosses. The name says it all: trees are draped with a thick carpet of moss.
Here is the recipe for a temperate rainforest: Plenty of rain, relatively moderate temperatures (rarely hot and rarely freezing), epiphytes (mosses, ferns and lichens), large old trees, nurse logs, and elk. Olympic National Park has the largest population of Roosevelt Elk in the USA. Elk limits the plants on the forest floor to a reasonable size to allow for continuous regrowth and prevent overcrowding.
Even in death these giant trees still amaze.
I was humbled to stand amongst these gentle giants. Some of these cedars had bases over 30 feet in diameter.