Koa Constrictors: Studying Things That Slow the Growth of Koa Crop Trees
Koa is one of the most valued of tropical woods. A particular type of koa tree, called Acacia koa, is found in the Hawaiian Islands. The wood from this tree is used to create furniture, cabinets, carved bowls, canoes, surfboards, body boards, ukuleles, and guitars. Unfortunately, the future demand for koa wood will not be met unless better ways are found to grow koa crop trees today.
After the article, read a short essay about canoeing and surfing in ancient Hawai'i.
You can also read the cultural essay separately in the Cultural Essay tab below.
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In this FACTivity, you will explore the reasons the scientists in this study might have chosen to be involved in the study.FACTivity – Koa Constrictors
In this FACTivity, you will explore the reasons the scientists in this study might have chosen to be involved in the study.
Glossary
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Paul Scowcroft
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Standards addressed in this Article:
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ESS3.C-M1
Human activities have significantly altered the biosphere, sometimes damaging or destroying natural habitats and causing the extinction of other species. But changes to Earth’s environments can have different impacts (negative and positive) for different living things.
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ESS3.C-M2
Typically as human populations and per capita consumption of natural resources increase, so do the negative impacts on Earth unless the activities and technologies involved are engineered otherwise.
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LS1.B-M4
Genetic factors as well as local conditions affect the growth of the adult plant.
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LS2.A-M1
Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors.
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LS2.A-M2
In any ecosystem, organisms and populations with similar requirements for food, water, oxygen, or other resources may compete with each other for limited resources, access to which consequently constrains their growth and reproduction.
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LS2.A-M3
Growth of organisms and population increases are limited by access to resources.
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LS2.C-M1
Ecosystems are dynamic in nature; their characteristics can vary over time. Disruptions to any physical or biological component of an ecosystem can lead to shifts in all its populations.
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LS4.D-M1
Changes in biodiversity can influence humans’ resources, such as food, energy, and medicines, as well as ecosystem services that humans rely on—for example, water purification and recycling.
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Cite specific textual evidence to support analysis of science and technical texts.
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By the end of grade 8, read and comprehend science/technical texts in the grades 6-8 text complexity band independently and proficiently.
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Determine the central ideas or conclusions of a text; provide an accurate summary of the text distinct from prior knowledge or opinions.
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Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks.
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Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 6-8 texts and topics.
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Analyze the structure an author uses to organize a text, including how the major sections contribute to the whole and to an understanding of the topic.
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Analyze the author's purpose in providing an explanation, describing a procedure, or discussing an experiment in a text.
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Integrate quantitative or technical information expressed in words in a text with a version of that information expressed visually (e.g., in a flowchart, diagram, model, graph, or table).
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Distinguish among facts, reasoned judgment based on research findings, and speculation in a text.
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Compare and contrast the information gained from experiments, simulations, video, or multimedia sources with that gained from reading a text on the same topic.
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Culture
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People, Places, and Environments
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Production, Distribution, and Consumption
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Science, Technology, and Society
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Time, Continuity, and Change
What Is a Natural Inquirer Journal?
A Natural Inquirer journal is a collection of 4-8 articles on a related science topic. Journals are written for a middle school audience, but they can also be adapted for both high school students and advanced upper elementary students. Some journals are particularly suited to high school students; you can find our grade level recommendations in the tags on the product page or by filtering journals by grade level.
Journals include:
- Four to eight articles based on published, peer-reviewed research papers; the articles keep the research paper format (see more below) but are written in language students can understand.
- A FACTivity for each article, which is an activity to complete after reading the article. The FACTivity helps reinforce major science concepts from the article. These activities are designed to be easy to implement, with few material requirements and options for adapting them for your audience or available resources. Some articles in a journal may have two FACTivities.
- A short “Welcome to the journal” article about key background information and science concepts that unify the articles included in the journal
- A glossary of new terms for each article and the introductory materials.
- A list of related Natural Inquirer publications for each article as well as outside references.
- Standards correlations, including Next Generation Science Standards, addressed in the articles and the FACTivities.
Journals may also include additional essays (called spotlights), other activities (like crossword puzzles or vocabulary challenges), and more.
Reading Modes
Journals are available in three different formats:
- Hard copies can be ordered from the website and shipped, all free of charge.
- PDF versions of the printed journal can be downloaded free on the website. The PDF version directly replicates the content and layout of the printed version. You can also download individual articles as pdfs.
- The “Read Distraction Free” option allows the individual articles to open in their own window, without the rest of the website being visible. These articles can be found under the “Articles” tab. This version allows readers to scroll to particular sections of the article using the sidebar menu on the left side of the screen. This version also has interactive Reflection Sections and Number Crunches. Students can enter their answers, submit them, and then receive the correct answers to double-check their work. Submitted answers are not saved on the website and will disappear once the window is closed.
What's in a Natural Inquirer Article?
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Meet the Scientists
This section introduces the scientists (and others) who worked on the study. In their own words, they each share a memorable science experience, a favorite research project, or something they learned during the course of their education or research.
Use this section to:
- Introduce kids to the variety of people who work in science
- Introduce kids to the variety of scientific fields and give brief descriptions of science-related jobs
- Explore ways that people interact with science every day
Next Generation Science Standards (NGSS) applications:
- Science and Engineering Practices
- Crosscutting Concepts: Influence of Science, Engineering, and Technology on Society and the Natural World
Note that specific standards for this particular monograph are linked on this educator guide tab.
Other resources:
Many of the scientists and engineers featured in this section are also featured on our collector cards. Learn more about their work, how they got interested in their fields, and interesting projects they worked on. Cards can be printed as posters, too.
Thinking About Science
This section briefly describes a concept about science or scientific research. This overview can touch on topics like
- study type (longitudinal study, quantitative vs. qualitative data),
- behaviors of scientists (conducting literature reviews, collaborating with other specialists, replicating earlier studies),
- the practice of science (the scientific method, engineering design, data collection, randomization, controls and variables),
- or other aspects of science (bias, correlation vs. causation).
Use this section to:
- Reinforce steps in the scientific method and the process of science
- Encourage students to think about the practice of science and what it can and cannot tell us
- Consider the many types of scientific study and what information each type can provide
Next Generation Science Standards applications:
- Science and Engineering Practices
- Life Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular monograph are linked on this educator guide tab.
Other resources:
You can use key words to search for other or related scientific topics on our website (e.g. “longitudinal study,” “bias,” or “sampling”).
Thinking About the Environment
This section provides a brief overview of a topic or concept in environmental/life science. The topic or concept is directly related to the research study that follows. Examples of topics include the carbon cycle, the water cycle, habitat fragmentation, phenology, biodiversity, and ecosystem services.
Use this section to:
- Provide important background information to help students understand the research study
- Serve as a quick reference during reading or class instruction
- Connect the research article with other activities or media on the same topic
Next Generation Science Standards applications:
- Life Science and some Earth Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular monograph are linked on this educator guide tab.
Other resources:
You can use key words to search for more resources on life or earth science topics on our website (e.g. “habitat,” “carbon,” or “genetics”).
Introduction
This section begins the scientific article format. Much like the published, peer-reviewed study this article is based on, the introduction provides background information for the study – what is currently known and what remains unknown. The introduction culminates in the question(s) the study hopes to answer.
The introduction is also the first section with a Reflection Section. This section includes two or three questions to help kids reflect on what they’ve just learned in the Introduction. If they are using the online distraction-free reading mode, they can answer these questions directly on the website.
Use this section to:
- Review important background information that kids need to understand the study
- Connect the study to the concepts addressed in the Thinking About Science and Thinking About the Environment sections
- Understand research questions and hypotheses, including generating their own hypotheses given what they already know
Next Generation Science Standards applications:
- Life Science and some Earth Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular monograph are linked on this educator guide tab.
Other resources:
Use one of the guided reading lesson plans to help kids follow the format of a scientific paper.
Methods
This section is the nuts and bolts of the study design – the who, what, when, where, why, and how of the research. Contained within the Methods section are usually maps of the study location or the set-up of study plots, as well as details about what data was collected and how.
The Methods section also ends with a Reflection Section – two or three questions to help students think through what they just read. These questions are interactive on the distraction-free reading mode.
Use this section to:
- Show students how experiments and studies are designed and carried out
- Explore sampling methods and randomization
- Introduce various data collection tools (e.g. camera traps, surveys, insect collection tools, weather stations, etc.)
- Explain bias and how studies are designed to remove bias
- Help students gain experience with map reading
Next Generation Science Standards applications:
- Life Science and some Earth Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular monograph are linked on this educator guide tab.
Other resources:
Many Methods and Findings sections contain Number Crunches, which are simple math exercises designed to help students interact with the data from the study.
Findings
This section summarizes the data collected during the study. The Findings section usually includes data tables or graphs and highlights the significant data points from the study. This section often mentions statistical analysis or the use of computer programs to model or analyze the data, though these methods are only discussed generally.
The Findings section also ends with a Reflection Section – two or three questions to help students think through what they just read. These questions are interactive on the distraction-free reading mode.
Use this section to:
- Have students practice reading and interpreting graphs and tables
- Compare results between variables and controls
- Explain the concept of statistical significance
- Discuss how no data or negative results still provide valuable information
Next Generation Science Standards applications:
- Life Science and some Earth Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular monograph are linked on this educator guide tab.
Other resources:
Search the website for “map” or “graph” to find activities where students can practice making and reading maps and graphs.
Discussion
This section concludes each article. In it, we summarize the main findings of the scientists’ study. Additionally, we present the scientists’ ideas about the limitations of their study, the big-picture impacts of their research, and the scientists’ plans for future study or action.
The Discussion section ends with a Reflection Section – two or three questions to help students think through what they just read, especially general take-aways from the study. These questions are interactive on the distraction-free reading mode.
Use this section to:
- Discuss what conclusions can and cannot be drawn from the available data
- Explain the difference between correlation and causation
- Explore study limitations and opportunities for further study
- Brainstorm ways the study findings could be applied to real-world situations
Next Generation Science Standards applications:
- Life Science and some Earth Science Disciplinary Core Ideas (depending on topic)
- Most Crosscutting Concepts (depending on topic)
Note that specific standards for this particular monograph are linked on this educator guide tab.
Other resources:
Use the “Designing Your Own Study” resource page for videos of scientists discussing their own research studies. The page also includes educator resources to help students plan their own scientific studies.
Additional Resources on the Website
On the website, we pair each journal with a variety of other resources, as well. Use the tabs on the product page to browse through the following:- Related activities, including the FACTivity for each article
- An “About” essay that gives some larger context for the research the scientists conducted or more information about the science topic from the journal
- A glossary of all boldfaced terms from the journal
- A “Scientists and Collaborators” page that lists the people involved in the studies in the journal; click on a researcher to reach their bio page and see what other articles they might be featured in
- A “Related Content” page that lists both Natural Inquirer resources about similar topics and also outside reference materials
Article Selection and Review
Natural Inquirer partners with the USDA Forest Service, so we source research studies by Forest Service scientists that have been peer-reviewed and published in reputable journals. Some of our articles have also been created in collaboration with scientists from other Federal agencies, such as U.S. Geological Survey and the United Nations Food and Agriculture Organization, universities, and other non-profits.
All journal articles are reviewed by scientists who conducted the original research study to verify scientific accuracy. Journals are also reviewed by student editorial review boards of middle or high school students before publication. Additionally, all journals are reviewed by the Forest Service and the U.S. Department of Agriculture before publication.
Every journal article includes a citation of its source study. Many educators pair the original research paper with our article to help more advanced students learn how to read formal research papers. The journal article then serves as adapted primary literature, bridging the two articles.Lessons
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In this lesson, students will increase their reading comprehension, critical thinking skills, and summarization and explanation skills. Students will role-play as members of the Natural Inquirer Twitter Team (now X...Lesson Plan – Twitter Team
In this lesson, students will increase their reading comprehension, critical thinking skills, and summarization and explanation skills. Students will role-play as members of the Natural Inquirer Twitter Team (now X... -
This lesson plan can be paired with any of the cultural essays from the Hawai’i-Pacific Islands edition of Natural Inquirer. After a brief introduction, students will read the cultural essay...Lesson Plan – Cultural Essay
This lesson plan can be paired with any of the cultural essays from the Hawai’i-Pacific Islands edition of Natural Inquirer. After a brief introduction, students will read the cultural essay... -
Students work in groups to analyze the Natural Inquirer article research study and give a brief presentation on their findings to their classmates. This lesson plan can be used with any Natural...Lesson Plan – Summarize and Present
Students work in groups to analyze the Natural Inquirer article research study and give a brief presentation on their findings to their classmates. This lesson plan can be used with any Natural...
Education Files
Canoeing and Surfing in Ancient Hawai‘i
The first Polynesians in Hawai‘i carved canoes and used these to travel over large distances. This is called “holomoana” or voyaging, a practice that continues today. In Hawai‘i, koa trees are still shaped into canoes. This is done for recreation and to keep alive the cultural practice and art of carving canoes. The art of carving canoes is called “kalai wa a.”
The best koa canoe trees are large, straight, and tall.
For Native Hawaiians and those who paddle traditional canoes, canoe building is a spiritual experience. In ancient times, canoe building was undertaken by traditional builders only after making customary offerings to the gods and receiving signs understood as blessings to continue.
Today, traditional offerings of thanks and respect are still practiced. From the time a decision was made to build a canoe until its first voyage, events were seen as good or bad omens. Koa trees were harvested in the mountain forests. The elepaio, a species of flycatcher, was observed over many days to note its tree-pecking behavior. If an elepaio was seen pecking into a tree, the tree was known to have insects. This would make it unsuitable for a canoe. Many of these traditional approaches to harvesting koa logs and shaping canoes are still practiced today.
Shaping a canoe from a solid koa log is complicated. After the canoe tree is cut, the future canoe is roughly shaped on the outside. After the outside shaping is done, the inside is hollowed out. In the past, this was done with stone tools. Today, power tools are also used. After the inside is hollowed out, the canoe tree is light enough to be hauled from the forest to the shore.
Hauling a canoe to shore was an important cultural event, requiring many people working (“laulima”) in unison (“lokahi”). The entire community celebrated this event. After bringing the canoe close to shore, the canoe builder finished shaping the canoe. This work was so respected that no one was allowed to talk in the building while the canoe builder was at work.
Koa wood canoes.
Koa wood canoes are long and thin and require an outrigger for stability. An outrigger is made up of a long float (“ama”) attached to the canoe with two bars of wood (“iako”). An outrigger does more than prevent capsizing. It keeps the canoe stable in even the roughest ocean conditions. Today in Hawai‘i, koa canoes are special vessels. They are used for racing and for ceremonies. Koa wood canoes are paddled by members of canoe clubs (“halau wa‘a”) during races. These paddlers are continuing an ancient practice that is a foundation of traditional Hawaiian culture.
The outrigger gives the long thin canoes incredible stability in even very rough water.
Another koa product is traditional surfboards (“alaia”). Koa was one of the three most common trees used for surfboards in ancient Hawai‘i. Koa wood surfboards are still used today. Surfboards came in many forms, shapes, and sizes. The long surfboards (“olo”) were carved from the wiliwili tree (Erythrina sandwicensis). The wiliwili tree produces very light but strong wood. Surfboards from these trees were reserved specifically for nobility.
Ancient Hawaiians began using wooden boards to surf waves very early in Hawaiian history. Although other early societies used surfboards, Hawaiian surfboard styles were more varied, and the Hawaiian art of surfing was more developed. Early Hawaiians created wood boards of various sizes so that different styles of surfing and different sizes of people could ride the waves.
Koa wood surfboards.
Surfing remains a way of life in Hawai‘i. Surfers ride waves today in the traditional manner. Paddling surfboards from a standing position has also become popular. Surfing ocean waves is an art that was begun thousands of years ago in Hawai‘i and will continue into the future.
Surfboards are sometimes paddled from a standing position.