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As we
go around the Starker Forestry Trail, there are several key ideas we typically
focus on. However, if the teacher/class has other interest areas, we will
address those areas as well. (These ideas can be reinforced with many
of the activities from Project Learning Tree as listed on the attached.)
- History
- People have inhabited the Northwest for at least 10-12,000 years.
The lands and waters provided for all their needs. As with people at
any other time or place, the Native Americans manipulated their environment
to better provide for their needs. They did this primarily by burning
the forest to create better habitat for the animals they hunted and
for the roots and berries they gathered. The early settlers found many
of the hills barren. Much of Oregon’s Coast Range was homesteaded
after the arrival of the wagon trains in the mid-1800’s. Many
of those homesteads disappeared during the Great Depression of the 1900’s.
Many of today’s forests are a result of the cessation of burning
by the Native Americans and the abandonment of homestead fields and
pastures.
- Seeds
- Trees reproduce by producing seeds. In the case of conifers, the seeds
are produced in cones. To disperse the gene pool and to lessen the competition
for nutrients, moisture, and sunlight, the seeds have wings to help
move the seed away from the parent tree.
- Diversity
- There is a great diversity of plant species that are readily visible
in a young forest. Animals are also diverse but are less visible. Later
in the field trip, we focus on an older forest that is much less diverse.
The canopy of the older forest is closed and allows much less energy
(sunlight) to reach the ground. This energy loss limits the amount and
variety of plant growth and reduces the variety of habitat niches.
- Food chains
- We
look at an old stump with termites and carpenter ants. Ants, termites
and fungi (decomposers) are often thought of as ‘bad guys’
but they also have beneficial affects; they help return the nutrients
in dead plants to the soil and lessen the fire danger. Sometimes, whether
or not something is a ‘good guy’ depends of the point of
view.
- Plant needs
- We see that plants must have nutrients, moisture, air and
energy to live. Plants use photosynthesis (a chemical process) to convert
these things into carbohydrates (sugars). Photosynthesis takes place
in the leaves’ chlorophyll. Animals (and humans) also need nutrients,
moisture, air and energy. Nutrients and energy generally come from plants
or other animals rather than directly from the soil and the sun. This
relates to the concept of food chains. [Plants are producers; herbivores
are primary consumers; and carnivores are secondary consumers. Humans
are either primary or secondary consumers.] Either directly (producers)
or indirectly (consumers), most organisms meet their needs by extracting
their nutrients from the soil, moisture from the water, and air from
the atmosphere. Energy comes from the sun either directly for plants
or indirectly (via plants) for animals.
- Competition
and dominance
- In the space they occupy, plants and animals must compete with each
other to meet their needs. This competition is both inter-specific and
intra-specific. Those species that do not compete well are eventually
crowded out by the stronger and more dominant competitors. They may
be present for only a short time in the plant succession process. Forests
are plant communities that are dominated by trees. The other plants
and the animals that do well in forests are adapted to survive in tree-dominated
plant communities.
- Change
- Seasonal changes occur constantly and, as the seasons
change, plants and animals change accordingly.Over the longer term,
plant communities change in predictable ways (plant succession) through
the processes of tolerance, competition, dominance, disturbance and
growth. As the plant communities change, animal habitat changes accordingly.
If the concept of plant succession (constant change) is valid, then
it follows that the “balance of nature” is probably not
valid. Disturbance in a plant community is a normal event and is typically
caused by insects, disease, fire, wind, volcanoes, harvesting and so
forth. Indeed, many species of plants and animals depend on disturbance
for their survival. Douglas-fir, for instance, depends on disturbance
to provide the sunlight it must have to successfully regenerate because
it is shade intolerant.
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