Walking Tour
Welcome to Ravenna Park! Ravenna park is located North of the University district, just past the University village, and extends next to Cowan Park. The park is mainly used for bicycling, running and walking through 4.5 miles of trails. It's a destination in itself, but is also a very helpful shortcut through town. The main trail is .75 miles in length, and is fairly flat.
Ravenna's history goes way back. In 1887, the park was privately owned, but was then purchased by the city of Seattle in in 1911. Since then, many trees have been felled, the creek was forced underground, and then daylighted in 2006.
This walking tour is designed to highlight some of the many exciting things that are located in the park-some that you might not notice if you didn't know what to look for.
1.) Geology/geomorphology
Ravenna park is in a ravine, that was carved out by the Vashon Ice sheet 16,000 years ago. The creek was an outlet of Green Lake, also created by the Vashon Ice sheet. However, with the lowering of the lake in 1911, the creek's source for water was cut off. Now, several springs feed the creek, which is a ghost of its former flow. However, evidence of the Vashon ice sheet can still be found.
When the glacier created the Puget trough 50,000 years ago, it carried sediment from the North, which would be modern-day Canada. I guess you could say we are on Canadian soil (now you don't have to flee Trump). But the glacier couldn't carry everything, and when the ice receded, it deposited large boulders, known as erratics.
If you walk along the main trail from the Cowan park end, you will walk under the 20th street Ravenna bridge, which is the second bridge you will walk under. Look to your right, and you won't miss spotting the large, moss covered rock. The Ravenna erratic is an igneous rock, specifically Granodiorite. Since the erratic is located at the bottom of the ravine, it can be speculated that the large rock tumbled down from the top of the hill. This is station 1 on the map below.
Even if you're not a rock nerd, the Ravenna erratic is a pleasant and unusual surprise. People of all walks of life stop to marvel at this large and curious feat of nature. I have seen people meditating and sunning themselves on the rock.
2.) Land Use History
Stream, Ravenna Park, Seattle, 1912
Courtesy UW Special Collections (Image No. SEA2076)
http://www.historylink.org/File/9559
Ravenna park has a long history of both reverence for the natural beauty of the land, and abuse and misuse of that land. In 1887 the park was a privately owned "Ravenna Springs Park", attracting people to the mineral springs with supposed health benefits. In 1892, a railway was almost built through part of the park, but the beauty of the land attracted so many people that the builders decided against it. The park was so popular, that by 1902, over 10,000 people had paid to enter the beautiful land. One of the highlights of the park was the "Roosevelt Tree", a 274 foot-tall Douglas Fir. The city bought the park from its previous owners, the Beck family, in 1911 for $144,920, and the land became available for public use. In the same year, the creek was forced underground, and two years later, the Roosevelt Tree was cut down. With the signing of a contract in 1926, the removal of old growth giants continued. In the 1960's, waste from the excavation to create I-5 was dumped into Cowen park, filling in parts of the ravine in order to create street-level playing fields. The abuse of Ravenna caused the formation of the Ravenna Creek Alliance, which seeks to maintain and restore the park. The creek was daylighted in 2006, which reconnected it to Lake Washington. On the map, I chose a spot on the trail where you can walk past the daylighted creek.
3.) Bird/Birds
Ravenna park has varying levels of foliage, which gives habitats for many different kinds of birds. It is easy to view birds from the top of the ravine, but the Cowen park entrance, so you can be eye-level with the tops of the trees.
There, you can spot many LBJs (Little Brown Jobs, as Kaeli taught us). These include Black capped chickadees with their easily distinguishable alarm calls,
Dark-eyed juncos with their contrasting heads,
Song sparrows,
and Bewick's wrens.
I have also seen a Spotted Towhee in the thicker brush at the bottom of the ravine, and have seen and heard the loud drumming of a Northern Flicker against a tree.
Dark-eyed juncos with their contrasting heads,
Song sparrows,
and Bewick's wrens.
I have also seen a Spotted Towhee in the thicker brush at the bottom of the ravine, and have seen and heard the loud drumming of a Northern Flicker against a tree.
I especially enjoy seeing Bewick's wrens, because the movement of their tails is very interesting. They flick their tails side to side, especially when they're agitated. They also flick their tails while they hunt for food.
It's also very easy to see and hear crows as well, especially near the erratic, where they frequently mob the Barred owl that inhabits the area (I haven't been lucky enough to spot it).
4.) Plant/Plants
The combination of forest and wetland in Ravenna park allows for a high diversity of plant species. This station by the creek is a perfect example of this diversity. Within the same 20 square meter area, you can find a large range of species. These include:
-Western Red Cedar (Thuja plicata), with it's fibrous bark, lacy needles, and swooping limbs, this tree is often called "the tree of life" in Native American culture. It was used for clothing, canoes, and housing. This tree likes to grow near water sources, which would make sense that it grows next to a stream at this station.
-Red Alder (Alnus rubra), a nitrogen fixing deciduous broadleaf tree, is easily identifiable by its smooth, ash-gray bark, and large, almond-shaped leaves, which are doubly-serrated. Red alders are a good indication of disturbed forest, which is true of Ravenna park.
-Pacific yew (Taxus brevifolia), a smaller evergreen tree, with its conspicuous red berry-like seed-cones. This tree also grows in moist areas, such as stream banks. Furthermore, Pacific yews are fairly shade-tolerant, which is important for its growth in the understory. This tree is a really "Christmas-y" tree.
-Giant horsetail (Equisetum telmeteia), part of the Juncaceae family (rushes), characterized by "branches" protruding from distinct bracts, and grows to about knee-height. Giant horsetails mainly grow in damp and shady places, like the marsh area that surrounds this station.
-Salmon berry (Rubus spectabilis) is a shrub with woody stem with thorns and trifoliate leaves. They can grow very tall, and there is one at this station that is easily over 6 feet tall. In the spring, they bear delicate pink flowers, and in the early summer, produce edible raspberry-like fruit. Salmon berries form dense thickets, which can be almost impossible to penetrate. They too, prefer moist environments, such as coastal forests.
5.) Visual Ecological Disturbance:
Ravenna park is a haven for many native plants, but is also filled with ornamental plants. These ornamentals may occur due to direct anthropogenic causes, such as intentional planting. They may also become part of the environment through indirect human contact, such as seed dispersal. Some of these introduced plant species become invasive, due to the fact that they thrive so well in Washington's mild and moist climate. Some of these, like holly
and english ivy,
along with morning glory (vines)
are highly invasive. The vines of english ivy and morning glories physically choke the tree or plant that they wrap around. The host will eventually die, due to lack of light, and causing weakness due to the excess weight of the vines. Other ornamentals in the park include horse chestnut,
with its distinct and somewhat prehistoric looking palmately compound leaves. The leaves grow in groups of 5-7, and turn a nice shade of yellow in the fall. There are also larch trees
in the park, which are a unique type of conifer that lose their needles in the fall. Some of the larch trees in Ravenna turn a lovely burnt-orange/red. They're quite a treat to see.
6.) Lichens/fungi:
There are many (I repeat, many.)...(No, I'm serious, so many) types of lichen and fungi in the Pacific Northwest. Lichen are especially hard to identify, because it is composed of both a fungus and a cyanobacteria or blue-green algae. However, lichen are sorted into three categories: foliose, fruticose, and crustose.
-Foliose lichen are leafy, kind of like pages in a book. Foliose lichen have different colors on their upper and lower cortices, which can sometimes be very difficult to distinguish, such as with Antler's Perfume.
-Fruticose lichen are hairy, or shrubby, and are the same color all around. They are the least tolerant of air pollution, due to the fact that their surface area is highly three dimensional.
-Crustose lichen are what you'd consider to be "crusty". They are the most tolerant to air pollution, because their surface area is only exposed where they attach to.
One lichen, which I was not able to identify, intrigued me the most. It isn't a lichen that we found when we were with Katherine Glew in the field. It's not hard to figure out why we didn't find it, because it grows only on the underside of a patch of salmon berry bushes that were draped across the creek. It was also growing on the rocks that make up the sides of the stream.
Lichen are incredibly beautiful and mysterious. That's probably why they're so fun to see in the field!
7.) Invertebrates:
At this station, there are three types of inverts that you are mostly likely to find. These are: Earthworms, Banana slugs, and millipedes. The first and last specimens will most likely be found under this log:
8.) Ecological interaction:
Big Leaf Maples (Acer macrophyllum) are very tolerant trees, as they can occur at almost all levels and stages of a forest (canopy level, age level). They are also very tolerant in their ability to host epiphytes. Epiphytes are plants that attach and grow on other plants, but are not parasitic. Epiphytes use their host only for support, not for nutrients or moisture. An example of an epiphyte is licorice fern (polypodium glycyrrhiza). Licorice ferns mainly grow on Big Leaf Maple trees, and are the most common type of fern to do so. In fact, if you see a fern growing on a tree, it will almost always be licorice fern. Licorice ferns are smaller than sword ferns, and have distinct red dots on the underside of each frond. At this station, a very large Big Leaf Maple, licorice ferns grow over the whole tree, from around 7 feet on the trunk, all the way up the tree, which is probably around 50 feet tall. The ferns grow with moss on the tree, both on the trunk and the limbs.
9.) Animal behavior:
On this Western Red Cedar (Thuja plicata) tree, we can see evidence of a woodpecker. The real mystery is... what kind of woodpecker? This is most likely the work of a Red-breasted Sapsucker, which are common to Ravenna Park. The Red-breasted sap sucker can be identified by its makes distinct and neat horizontal rows of holes that are about 1/4 inch in size. Sapsuckers drill into trees in order to feed on the sap of both hardwoods and conifers, which I think is very interesting. However, I can't be positive that it's a Sapsucker, because this tree is fairly large, with thick bark, that they do not prefer. Woodpeckers also drill loudly into trees as a method of communication, in order to attract a mate or ward off competitors.
The other woodpecker that it could be is the Northern flicker, which has similar drilling patterns. The Northern Flicker is an unmistakable bird, with black dots on its underside and black and red tail feathers.
All woodpeckers have very unique tail-feathers, which are individually pointed, which helps them stabilize against the trees.
Another fun fact about woodpeckers is that they belong to the Picidae family, which is funny because they "pick" at trees.
10.) Giant Sequoias!
For my tenth station, I thought I'd pick something that was more personal to me. Every time I've come to Ravenna park, I've seen a small patch of redwood trees. There are about six or seven trees, each with a few more growing from their bases. Redwood trees are a subspecies of Sequoias, which are part of the same family as cedar trees. Most famous are the redwood forests and Giant Sequoia forests in California, which includes "The President", one of the largest trees in the world.
I adore John Steinbeck's works, and find similarities between the settings of his novels and my own life. I was born in San Francisco, and lived an hour away from Monterrey, in a town very similar to Steinbeck's Cannery Row. Whenever I walk past this patch of trees, I am reminded how important the of documentation of nature is, not just for scientific reasons, but also for the purpose of enjoyment. Steinbeck's description of Northern California's beautiful forests have inspired millions to enjoy the same scenery half a century after his life.
Ravenna park is a haven for many native plants, but is also filled with ornamental plants. These ornamentals may occur due to direct anthropogenic causes, such as intentional planting. They may also become part of the environment through indirect human contact, such as seed dispersal. Some of these introduced plant species become invasive, due to the fact that they thrive so well in Washington's mild and moist climate. Some of these, like holly
6.) Lichens/fungi:
There are many (I repeat, many.)...(No, I'm serious, so many) types of lichen and fungi in the Pacific Northwest. Lichen are especially hard to identify, because it is composed of both a fungus and a cyanobacteria or blue-green algae. However, lichen are sorted into three categories: foliose, fruticose, and crustose.
-Foliose lichen are leafy, kind of like pages in a book. Foliose lichen have different colors on their upper and lower cortices, which can sometimes be very difficult to distinguish, such as with Antler's Perfume.
-Fruticose lichen are hairy, or shrubby, and are the same color all around. They are the least tolerant of air pollution, due to the fact that their surface area is highly three dimensional.
-Crustose lichen are what you'd consider to be "crusty". They are the most tolerant to air pollution, because their surface area is only exposed where they attach to.
One lichen, which I was not able to identify, intrigued me the most. It isn't a lichen that we found when we were with Katherine Glew in the field. It's not hard to figure out why we didn't find it, because it grows only on the underside of a patch of salmon berry bushes that were draped across the creek. It was also growing on the rocks that make up the sides of the stream.
I find this lichen to be highly interesting, and it raises a lot of questions. Is it intolerant of sunlight? Katherine told us that some lichen "sunburn", and develop bright pigment to combat the sun. Could this lichen possibly only exist near bodies of water? The moisture from the stream could be the reason for its adherence to the side of the branch closest to the water. Also, this lichen is purely white, without any other markings to suggest reproductive structures. In this case, the reproductive structures are probably microscopic.
Lichen are incredibly beautiful and mysterious. That's probably why they're so fun to see in the field!
7.) Invertebrates:
At this station, there are three types of inverts that you are mostly likely to find. These are: Earthworms, Banana slugs, and millipedes. The first and last specimens will most likely be found under this log:
Earthworms will most likely be partially coming out from the dirt, which is their home of choice. Earthworms are decomposers, so they are essential to the recycling of energy in the forest, which is why they're also an important part of composting. If you've never seen an Earthworm, they are pink to red in color, with fleshy skin, like that of a newt or salamander, but even more translucent. They move head first, and prefer to go under their obstacles instead of crawling over them (like me).
The millipedes under the log obviously prefer dark and moist environments. They are usually about an inch long, and light in color- I wouldn't say white, more of a sandy color. They play dead when they are introduced to stress, where they curl up in a tight ball, in the same manner that pill bugs do.
Banana slugs are most likely to be found near plants, but also prefer moist areas. They feed on leaves, and have similar skin to Earthworms. They are can be brown, yellow, or yellow with brown spots or blotches. They are decomposers as well, and create soil humus by recycling decaying matter.
8.) Ecological interaction:
Big Leaf Maples (Acer macrophyllum) are very tolerant trees, as they can occur at almost all levels and stages of a forest (canopy level, age level). They are also very tolerant in their ability to host epiphytes. Epiphytes are plants that attach and grow on other plants, but are not parasitic. Epiphytes use their host only for support, not for nutrients or moisture. An example of an epiphyte is licorice fern (polypodium glycyrrhiza). Licorice ferns mainly grow on Big Leaf Maple trees, and are the most common type of fern to do so. In fact, if you see a fern growing on a tree, it will almost always be licorice fern. Licorice ferns are smaller than sword ferns, and have distinct red dots on the underside of each frond. At this station, a very large Big Leaf Maple, licorice ferns grow over the whole tree, from around 7 feet on the trunk, all the way up the tree, which is probably around 50 feet tall. The ferns grow with moss on the tree, both on the trunk and the limbs.
The other woodpecker that it could be is the Northern flicker, which has similar drilling patterns. The Northern Flicker is an unmistakable bird, with black dots on its underside and black and red tail feathers.
All woodpeckers have very unique tail-feathers, which are individually pointed, which helps them stabilize against the trees.
Another fun fact about woodpeckers is that they belong to the Picidae family, which is funny because they "pick" at trees.
10.) Giant Sequoias!
For my tenth station, I thought I'd pick something that was more personal to me. Every time I've come to Ravenna park, I've seen a small patch of redwood trees. There are about six or seven trees, each with a few more growing from their bases. Redwood trees are a subspecies of Sequoias, which are part of the same family as cedar trees. Most famous are the redwood forests and Giant Sequoia forests in California, which includes "The President", one of the largest trees in the world.
Bibliography
- Blecha, Peter. "Ravenna Park (Seattle)." HistoryLink.org. Historylink, 23 Jan. 2011. Web. 15 Dec. 2016. <http://www.historylink.org/File/9559>.
- "Northern Flicker." All About Birds. Cornell Lab of Ornitology, n.d. Web. 12 Dec. 2016. <https://www.allaboutbirds.org/guide/Northern_Flicker/lifehistory>.
No comments:
Post a Comment