Posted by on May 5, 2015 in Blog |

This past winter, seventh grade students and faculty from Catlin Gabel school invested time, effort, skill and heart into the important work of helping us better understand the workings and condition of Hyla Woods’ Timber Forest.  Like all students who come to the forests, their work was organized around several simple, clear, and real questions.  There’s were: “How can we assess the health of an ecosystem? and How healthy is the ecosystem of Lousignont Creek?”   On the morning of April 22nd 65 students presented their answers to the Hyla Woods team.

Two main forms of inquiry and data collection and analysis were used – scientific analysis of the creek and poetry.  Through their excellent presentation, the students shared the results of both approaches.  The poems were assembled into a beautiful and inspiring published anthology of poetry.  Details of the stream science were communicated through well organized presentations as well as through individual student blog posts.  Students selected what they think are some of the best blog posts.  They are pasted below and we encourage you to read them.  All on the Hyla Woods team want to thank the students, the teachers -Jesse and Christa, and the adult helpers for all of the effort and care that went into this successful project.  The poems will provide inspiration for years to come and the scientific results with inform our ongoing restoration work and help us better understand the ever changing health of this wonderful creek.


Hyla Woods, and Why it is Healthy  – by Chiara

This year, our 7th grade class of Catlin Gabel, went to Hyla Woods, located in Timber, OR. We went to these woods to figure out the answer to our primary essential question: how can we tell if an ecosystem is healthy? We’ve been trying to figure out an answer to our question, using Hyla Woods as our ecosystem. Peter and Pam Hayes own the beautiful, and quite fascinating, forest and ecosystem known as Hyla Woods. Thanks to them, we were able to go. Also, thanks to their stunning forest, they are able to make a timber industry, so if you are interested in buying wood, visit their website!
Now, back to science! To investigate clues to answer our unit question, our class went on a field trip to Hyla Woods, twice. The first time we went, we spent the entire day there doing experiments. We already had been divided in research groups, and in our research groups, we collected data about our site. We marked down the weather first, which was overcast. (Typical Oregon.) We did a whole bunch of tests, and we also made a leaf pack. A leaf pack is a small sack that we filled with leaves, to try and see how many invertebrate came to inhabit the sack. When we would come back the next time, we would only stay half a day inspect what we found.

When we drove back the second time, it was a cloudy day. (Oregon, again!) We also redid all the tests, although the ones revolving the temperature of the water and air were omitted because our thermometer had some problems. We also investigated our leaf pack, but, sometimes, bad weather leads to strong winds and strong currents. (Again, typical Oregon.) So, when we came back, our leaf pack was still abnormally there, but was buried under 4 inches of sand. In other words, it wasn’t very useful when we were trying to find clues for our essential question: how can we tell if an ecosystem is healthy? Well, how can we tell if all we got in our leaf pack are worms?!? The answer to that question is simple; you see if anyone else in your science class had found any invertebrates, and yes, we had a research team in our class who found a whole truckload of invertebrates! They were was so cool to look at!
Since now all I’ve been telling you was the story. What tests did we do, and what does it mean in an ecosystem? Well, lets start with temperature. Air temperature affects water temperature, and water temperature affects the kinds of fish and macroinvertebrates inhabiting the river. Since lots of creatures that live in ponds and rivers are cold-blooded, they don’t control their body temperature. So if water temperature isn’t stable, if can cause the organisms stress. According to the data we collected as an entire grade in different sites along the river of Hyla Woods, the average water temperature the first time was 7.4 degrees C, while our research team got 7.5, and the second time we had gone the average was 5.6 degrees C, and our second time results were omitted to “technical difficulties”.
Now, I’ll explain to you a little bit about pH. First of all, pH measures the acidity of water. A pH scale goes from 0-14, 7 being the most neutral. 7 is also the pH of your drinking water, so that’s what we’re trying to shoot for when we measure the pH. Anything below 7, as in, 0-7, is acidic. What would fall into that category are lemons and vinegar, for example. Anything above 7, as in 7-14, would be called basic. Things that would fall in this category would be ammonia and soap, for example. But how does this affect organisms? Well, pond and river water needs to be between 6-8 pH, otherwise fish could die from the acidic levels. For the aquatic creatures, it would be just like drinking vinegar and ammonia. Those aren’t good drinking sources for animals. As a research team, we collected 6.5 both times we went to Hyla, which is a good acidic level. Our grade averages are also 6.4-6.5.
Have you ever asked yourself: do fish breathe? The truth is, they do. You’d expect they didn’t, since they live underwater, when in reality, they do. Since fish need oxygen, it’s important that there’s a good amount of oxygen in water, otherwise fish could die. Dissolved oxygen (DO) measures how much oxygen is in water, so it measures the organisms’ breathing conditions. Dissolved oxygen can vary depending on the number of aquatic plants in the river, because underwater plants photosynthesize as well, and when they do the air is released in the water. It can also vary from the wind, because when air is mixed with water some oxygen molecules join the river. Most organisms need 8-12 parts per million of oxygen in water. Our group collected 10 ppm of DO both times we went to Hyla Woods. As an averages, our grade collected 12.2-14.2 ppm, which is very good.
Frost Flowers!

Turbidity. What does it mean? Turbidity measures the amount of mist in a river/pond, but in our case, a river. Okay, but why is it important? Turbidity also determines how much light can pass through water, which can affect the amount of sunlight that plants get underwater, which can decrease the amount of photosynthesis, which decreases dissolved oxygen in water, and the aquatic plants are affected. Sediment in water also collects heat from the sun, which warms water, and warm water loses oxygen, so it can also affect the dissolved oxygen of the water. The sediment can also harm the gills of organisms, and it makes it harder to see and catch food. How is turbidity affected? Turbidity is affected by animals that disrupt sediment, floods, if the vegetation is disturbed, and pollution. So, the cleaner water, the better. Both times we went to Hyla Woods, the water was incredibly clean (though it was slightly foggier the second time because of the fast currents) yet, it remained at a steady 125+ cm. Our grade average the first time was 122 cm, and the second time we went the average was 109 cm.

Last but not least, the aquatic macroinvertebrates themselves. There are many macroinvertebrates, ranging from snails and worms, to mayflies and beetles. But how do they help us figure out the answer to our essential question? They help, because there are some macroinvertebrates that are more sensitive than others. If a macroinvertebrate is sensitive, like the stonefly, they can’t survive in sudden river changes. If a macroinvertebrate is tolerant, like leeches, it means they can still live and survive in river changes. For example, if the water temperature changes by 10 degrees C, the sensitive macroinvertebrates would have a hard time surviving, while the tolerant ones would be able to. That’s not all, there’s a third category. There are some macroinvertebrates that are in between, such as dragonflies and clams, where they are somewhat tolerant. In our research group, since our leaf pack was under sediment, we found 13 aquatic worms (tolerant), 1 cranefly (somewhat tolerant), and 1 planarian. I’ve looked at our grade’s database, and we have a good mix of tolerant and sensitive. The groups whose leave packs worked right, they got more sensitive than tolerant. That’s the result you should get in a healthy ecosystem, because if sensitive creatures inhabit the ecosystem, it means the habitat suits their restricted limits.                                                                                                                                                                                                                                                                                                                There is something called an EPT score, which is the percentage of mayflies, stoneflies, and caddisflies, which are all three sensitive macroinvertebrates. An EPT score helps you determine whether an ecosystem is healthy, (just what we need!) and the types of macroinvertebrates in an ecosystem. Our research team’s is 0, but because our leaf pack was buried under sediment. The grades’ average EPT score is 45, but keep in mind that some research teams didn’t contribute to the EPT score, because of some technical dilemma. Then there’s something else called a biotic index, which measures the stream quality. As our Biotic Index, our team got 7.666, and as a grade the result was 4.5, which was in the good water quality range. The best water quality is less than 3.75, but we were close!
           Gosh, I’ve written a lot about the ecosystem. Yet, I’ve only half-answered our essential question: how can we tell if an ecosystem is healthy? Well, with all that I’ve gone over, I’m going to finish answering it. In any healthy ecosystem, you need support on all aspects of it, because if you’re missing on just one thing, or if something happens, it can cause a huge stress and eventually fatally affect it. So, all aspects of an ecosystem have to have a positive effect on each other. For example, if your ecosystem has bad acidity, it can affect the macroinvertebrates, plants, and their behavior. But, back to the question. Before you can tell if an ecosystem is healthy, you’ve got to find all the puzzle pieces, then put them together. Like I did in this paper. I think this ecosystem known as Hyla Woods, is healthy.
The River at Hyla Woods!


Hyla Woods Eco-Narrative Blog Post
by Annika

Louisignout Creek

What makes an ecosystem healthy? This question is what we were trying to figure out during our February 3rd and March 5th field trips to Hyla Woods, located in Timber, Oregon and managed by Peter and Pam Hayes. Our class was split up into groups and each group had a different section of the Louisignout Creek. In our groups, we conducted many tests on the water, including water temperature, air temperature, dissolved oxygen, pH, and water turbidity. We also observed the creek bed and banks for different types of plants and signs of erosion. The water, water temperature, plants, animals, air, light, and soil all have to work together in a healthy ecosystem.

The Macroinvertabrates we found
During our first trip to Hyla Woods, each group left leaf packs in many sections of the creek. Leaf packs are made by putting different types of leaves into a mesh bag and placing it into the stream. We left the leaf pack in the water for almost four weeks. In March, we collected the leaf pack to see if there were any macroinvertebrates in it and to classify them. Our leaf pack was very successful. We identified 35 mayflies, 6 stoneflies, 3 caddis flies, 2 alderflies, 1 true fly, 15 aquatic worms, and 4 snails. More diversity in the types of species is good for the Hyla Woods ecosystem. The calculation of our leaf pack’s Biotic Index was 4.68, which indicates “good” water quality with some “organic pollution.” The EPT score, the percentage of mayflies, stoneflies, and caddisflies within the total sample, was 66.7%. The higher the score, the healthier the creek.
Freshwater plants and animals thrive in a pH range of 5.7 to 7.5. It is important that pH stays within this range to maintain a healthy ecosystem for plants and animals. If the pH falls below 6.5, the bones of fish may become soft and females may be unable to lay eggs. Also, aquatic insects, which fish often eat, will not be able to survive if the pH is too high or too low. Both times we went to Hyla Woods, we measured a pH of 6.5, within the ideal range for animals and plants.

We also measured water turbidity, a measure of the water clarity, using a turbidity tube. Water that has a high level of turbidity is hard to see through because it contains suspended solids, such as sediment, dead plants, and bacteria. High levels of turbidity can come from soil erosion and water runoff.  High sediment levels can clog the gills of aquatic life and also cloud the water so fish cannot see their food. We observed the creek banks for signs of erosion and runoff and noted that there was minimal erosion of the creek bank at our location. The length of the column of water in the turbidity tube is the transparency of the water. The greater the length, the clearer the water. In February, we measured 100 cm and in March, we measured 115 cm. The average length of 107.5 cm translates into a turbidity of 0.93. On the turbidity scale, a value less than one means that the water is “very good; water is quite clear”.

We also tested for dissolved oxygen, a measure of how much oxygen there is in the creek. Aquatic organisms absorb dissolved oxygen through gills or directly through their skin. Dissolved oxygen levels in the range of 7 to 11 ppm are required to support a diverse range of aquatic life. Cold water species like salmon do best at a concentration of 8 ppm or above. Our measurement of 10 ppm for dissolved oxygen in Louisignout Creek shows a level that can support salmon and other aquatic life.

For water temperature to meet the standard for “excellent” water quality, the temperature must be lower than 18 degrees Celsius. In February, the water temperature was 7 degrees Celsius, and in March, the water temperature was 5.5 degrees Celsius. 13 to 20 degrees Celsius is the temperature range suitable for most aquatic life. Salmon need water that is cold because cold water holds more oxygen. Although, our measurements showed lower temperatures, the higher air temperatures in the spring and summer will warm up the water. The temperature of a creek varies at different times of day and times during the year.

Our class observed dead salmon in the river and along the river
bed. This is a good sign for the Hyla Woods ecosystem because it
means that the salmon are trying to spawn in the creek. The presence of salmon, the results of our measurements for pH, turbidity, dissolved oxygen, and temperature, the diversity of macroinvertebrates in our leaf pack, and our calculations of Biotic Index and EPT, indicate a healthy ecosystem at Hyla Woods.