Monthly Archives: January 2016
Native American Uses of the Forest
By Bruce Rottink, Volunteer Nature Guide and Retired Research Forester
For thousands of years before settlers from the eastern United States or Europe arrived in the vicinity of what is now Tryon Creek State Natural Area (TCSNA), Native Americans called this forest home. The Native Americans used resources ranging from rocks to trees to animals. However, the basis for much of the Native American life was the plant life of this area. They relied on the forest and waterways for everything; food, medicine, tools, clothes, everything!
What kinds of plants did they eat?
There were lots of plants and fruits the Native Americans ate. Some of the more tasty items were the berries from the forest, like the salal (Gaultheria shallon) berries. Pictured below are the plant and berries. I’ve planted salal in my front yard, and they are delicious on my morning cereal!
Another food the Native Americans sometimes ate were the berries of the Oregon grape (Mahonia nervosa). In the photo below, the blue-colored berries are almost ready to eat, while the greenish ones have a way to go before they are ripe.
I’ve tasted Oregon grape berries too. My taste buds’ response was, o-o-o-o-kay! I think they’re about half way between yummy and yucky. According to ethnobotanists, people who study how different groups of people use plants, the Native Americans would sometimes mash the fruits of the salal and Oregon grape together. In this way, they had a greater total quantity of food, which still tasted “kind of” good.
Another category of food plants is represented by the skunk cabbage (Lysichitum americanus) pictured below. This plant has a large underground tuber (note: potatoes are also tubers). Unfortunately, the skunk cabbage tuber tastes awful. It had to be specially prepared to become even edible. Ethnobotanists refer to this as a “starvation food” meaning that you only ate it when the alternative was starvation. If you’ve ever smelled a skunk cabbage in the spring, you understand why it wouldn’t necessarily pop into your mind as a good food item!
What kind of medicine is in the forest?
For the Native Americans, the forest was their drugstore. Just one of the many medicinal plants used by some Native Americans was the licorice fern (Polypodium glycyrrhiza). The pictures below show the licorice fern growing on the side of a tree at TCSNA and the second photo shows a cleaned-up licorice fern plant that was growing on a branch that was blown down during a windstorm. The rhizome can be thought of as a perennial stem, while the leaves come and go with the seasons.
The Native Americans cleaned up the rhizome of the licorice fern and chewed it as a cough and sore throat remedy. Once when I was not at TCSNA, I cleaned up a licorice fern rhizome and chewed it a bit. It does taste faintly like licorice. Within 30 seconds of starting to chew the rhizome, I got a tingle right in the back of my throat. Although I was perfectly healthy at the time, the fern was definitely affecting me. It would have been interesting to see the effect if I’d had a cold or sore throat.
What kind of tools did they find in the forest?
One of the tools the Native Americans found in the forest was the horsetail (Equisetum spp.), pictured below. This primitive plant contains a lot of silica crystals. Silica is the most common material found in sand. The Native Americans used this as a “natural sandpaper” for finishing their wooden tools. The effectiveness of this tool can be demonstrated by using it to polish a penny.
The effectiveness of polishing is shown in the “before and after” photos below.
What kind of clothes did they make from forest plants?
The western redcedar tree (Thuja plicata) had many uses. To give just one example, its bark is very fibrous. With careful harvesting and care it can be used to produce everything from rope to clothes. Pictured below is a cedar bark rain hat. These were widely made and used by the Native Americans on the Pacific coast. According to some sources, they would sometimes treat this hat with pitch to make it even more water repellent.
But of all the clothing that the Native Americans made from forest plants, the one that always intrigued me was that they used moss for baby diapers. I wondered how well those would work. Strictly as a public service, I decided to run an experiment and find out.
You personally tested moss as diapers? Seriously?
Before your imagination runs wild (it may already be too late), let me explain. I took samples of five water-absorbing things:
- A major brand of modern disposable diaper
- A sponge
- A pile of moss
- A traditional cloth diaper
- A bunch of paper towels
I weighed each item dry, making sure I had between 60 grams and 90 grams of each material (this is about 2 to 3 ounces). I then soaked each item (separately) in water completely covering the test material with water for 15 minutes. Then I put each material on a sheet of screen to drain. When the drops of water falling out of the material were 10 or more seconds apart, I considered the material to be completely drained. I then weighed each item wet. I calculated “absorbency” by dividing the weight of water absorbed by the dry weight of the material.
The results are displayed in the chart below.
Modern diapers with their SAP (Super Absorbent Polymer) ingredient can absorb more than 80 times their weight in liquid! But let’s cut to the chase. I was fascinated to see that moss, the key ingredient in the Native American diaper could absorb 7.4 times its dry weight in water. In contrast, a classic 100% cotton, all-cloth diaper can only absorb 3.5 times its own dry weight in water. So the Native Americans were using the superior diapering material! Wow!
At home in the forest!
To the Native Americans, the forest was their home, their grocery store, their pharmacy, their hardware store, their everything! They adapted to their environment to meet all their needs.
Weather and Climate: Looking Back and Ahead
By Bruce Rottink, Volunteer Nature Guide and Retired Research Forester
Talk about a double whammy! The Portland area, including Tryon Creek State Natural Area (TCSNA), has set an all-time record for December rainfall, and the 2015 United Nations Climate Change Conference has just wrapped up in Paris! Lots of people are thinking about the weather and climate now!
The growth, survival and distribution of the plants at Tryon Creek State Natural Area (TCSNA) are affected by a host of factors. These factors include climate and weather, but also things like soil chemistry, soil depth, the steepness of the slope the plant is growing on, and soil moisture holding capacity. Probably the two most important weather variables are temperature and rain fall. Most of the discussion around climate change has to do with increases in the mean annual temperatures. This is a good place to start, but perhaps inadequate to explain all the changes we might see.
So how might climate change effect our forest?
Climate change might affect TCSNA in many ways, for example, altering the species composition of the forest. I am in my third year of monitoring the growth and development of a variety of plants in my phenology study at TCSNA. In my monitoring I visit the same plants every week to ten days and record their status. Perhaps looking at some of the results might provide a peek into the future. One of the species that I am monitoring is Pacific waterleaf (Hydrophyllum tenuipes). As the waterleaf tends to form dense clumps, I am monitoring approximately a 3-foot diameter circle of plants at each of four separate areas, rather than just trying to track a single stalk.
Pacific waterleaf is a perennial plant, which sends new shoots up every year from rhizomes. Think of rhizomes as “underground stems”. The above ground shoots die back in the “off season” and only the roots and rhizomes persist from year to year. At TCSNA waterleaf is generally from 40 to 60 cm (16 – 24”) tall at maturity. These shoots die back sometime in the summer, generally after they have produced a crop of seeds.
Reviewing the phenological records, the last two years have seen a lot of variability in the behavior of the Pacific waterleaf at TCSNA. The chart below indicates the presence or absence of waterleaf leaves at each of the four monitoring sites on a weekly basis.
Weekly Presence/Absence of Pacific Waterleaf at Four Locations at TCSNA over Two Years
Key: Yellow = Waterleaf Absent; Green = Waterleaf Present;
Week 1 = first week in January, Week 26 = end of June, Week 52 = last week of December
The late-winter through early-summer growth is the time when the waterleaf is making the vast majority of its sugar to support the plant, AND when the plant is producing seeds. The second emergence of leaves is around weeks 40 to 45 (roughly October thru early November). This “second leafing out” produces leaves that tend to be fairly small and I’ve never seen this second leafing produce flowers, much less seeds. And, as you notice, there is a certain amount of “now you see it, now you don’t” with this second leafing out. In at least some cases, the second leafing out leaves are eliminated by a serious frost.
It is interesting to note that on the Middle Creek Trail, there is never a “second leafing out.” The major difference between the Middle Creek waterleaf patch, and all the others is that the Middle Creek patch is on a significant slope, and is more exposed to direct sunlight. All the other patches are on flatter sites. Thus, it may dry out sooner than the other patches, and not have the late-season water it needs for a second set of leaves.
Why are these years so different?
- One thing that you can see immediately is that the green bar (indicating the presence of waterleaf plants) consistently ends earlier in 2015 than in 2014 for any given site. In 2015 the leaves disappeared on average 7 weeks earlier than in in 2014. This is a significant amount of time.
- The seeds of the waterleaf mature approximately in mid-June, so in both cases the plants survived long enough to produce seeds, and nothing more. It is likely that the leaves which persist after seed production are producing sugars to help support the plant for the next growing season.
What could have caused that difference?
The contrasts in weather between 2014 and 2015 are dramatic. I think the weather data probably goes a long way in explaining this year-to-year behavioral difference.
First let’s look at the (Portland) air temperatures maximum and minimum for the years. In each chart, the highest average minimum or maximum air temperature is highlighted in color. Where the temperature for any month was more than 5° F higher than any other year, it is highlighted in red.
Average Daily Minimum Air Temperature – Portland
(In °F; higher year highlighted red)
You can easily see that for most of the spring and early summer months, the minimum temperatures were higher in 2015 than in 2014. But that’s just the start. The next chart tells us even more.
Average Daily Maximum Air Temperature – Portland
(In °F; higher year highlighted in red)
Again, for most of the spring and early summer months, the average maximum daily temperature was higher to dramatically higher in 2015 than in 2014. The yellow-highlighted months are more than 5°F warmer than the comparable month in 2014. The average high temperature in June 2015 was almost 10° F higher than June 2014! This higher temperature would probably cause the plants to lose more water, produce less sugar, and grow less in 2015 than they did in 2014. But the icing on the cake is yet to come. Just take a look at spring/summer rainfall data (from the PCC Sylvania rain gauge station).
February through June Rainfall
Wow! The early growing season rainfall in 2014 was nearly twice what it was in the comparable time in 2015.
The “growing season” for Pacific Waterleaf in 2015 was both hotter and drier than it was in 2014. The result was that the above ground waterleaf shoots disappeared on average 7 weeks earlier. Yikes! A seven-week difference in leaf persistence is not trivial.
I can’t wait to see what kind of impact this has on waterleaf in the 2016 season.
Think of all the linkages that there may be between waterleaf and the other organisms in the forest. Possibly less food for waterleaf-eating insects, less cover for mice scurrying around looking for food, fewer waterleaf seeds for food, and possibly increased soil erosion from late summer rainstorms.
This is the story of just one species of plant, but it might foretell the challenges we face if climate change continues unabated.