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Threats to renewability of forests include old-growth logging, forest fires, and tree plantations. Threats to renewable rangeland include overgrazing, deforestation, and desertification. Much of the public forests are managed by the USFS and federal rangelands are managed by the BLM. A discussion of the Tragedy of the Commons is also included.
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Transcript provided by YouTube:
Hi. It’s Mr. Andersen and this environmental science video 17. It is on forestry and rangelands.
You might look at a picture like this and say it is wilderness. But it might not be.
It might be a privately owned forest. And just like we have farmers on crop land, we
might have foresters that are monitoring each of the trees and figuring out when is the
best time to harvest these trees. And one technique they use is called clear cutting.
You might look at this and say this is awful. It seems like we are destroying the whole
forest. Why would you ever do this? Well imagine if you own a forest. And you are going to
harvest the lumber. Well which trees are going to give you the most money? It is going to
be the largest ones. So you might just harvest those. But now we are faced with another problem.
We are going to have smaller trees that are not getting direct sunlight and as all of
these trees grow up we are going to have that same problem again. So a technique that they
will sometimes use is removing all the trees, we call that clear cutting. And then replanting
with what is called a tree plantation. So now all of the trees are the same age. They
are going to get direct sunlight and they are going to be harvested at the same exact
time. Now there are some problems with this. So in some areas it is going to promote soil
erosion which could lead to mud slides. We are going to decrease nutrients in that area.
And it is going to decrease the biodiversity as well. So what I am talking about is land
management of forests to provide lumber. But I am also going to talk about land management
of rangelands through grazing to produce things like cattle. Both of these resources are renewable.
In other words if we do a good job they are going to keep coming back again. But there
are threats to that renewability. So if we are looking at a forest, if you have an old
growth forest, those are trees that are really old, sometimes hundreds if not a thousand
years old, they are never going to come back in a renewable fashion. We also have forest
fires. And then these tree plantations are not threats to the tree plantations themselves,
but are threats to the biodiversity of our planet. If we are looking at grazing we could
have overgrazing where you are removing the producers. We could have deforestation where
you cut down the trees to provide for grazing. And these two things together can promote
the formation of deserts through desertification. So all of this management could apply to private
land but could also apply to public land. And in the US we have a lot of public forests.
Those are generally administered by the US Forest Service. We call those national forests.
And then we have a lot of rangelands, federal rangelands. And a lot of those in the US are
administered by the BLM. And so forests provide lumber for us. And we have this quaint view
of a logger with an ax cutting down a tree. Like everything it has been highly industrialized.
This is a sawmill. It is feeding the wood through and we are using lasers to get the
optimum amount of lumber out. Techniques they use are clear-cutting, where we can remove
all of the trees, replant it with a tree plantation. And then we can do selective cutting. And
so when we are removing just specific pines that is going to cost more money but maybe
healthier for the forest. But not only do forests provide lumber they provide an area
for recreation. They reduce erosion. They are carbon sinks. So through photosynthesis
they can take in a lot of carbon dioxide. And also they promote the biodiversity, the
ecological services on our planet. What are some threats to all of those? Well if we harvest
old growth trees, so these are things like redwood trees, big spruces in British Columbia,
that have taken hundreds of years to grow, once you remove them then they are gone forever.
They are not going to have time to grow back. And if you look in North America, 90 percent
of our old growth has already been harvested. So the deed has already been done. Forest
fires are another threat. And so on the east coast of the US we do not have that many forest
fires. It is because we have a lot of rain. But as people move West they saw these giant
forest fires. They are a natural part of forest ecosystems, but big fires, like in 1910, they
called it the big blow-up, killed a number of people. And so it led to fire suppression.
I grew up with Smokey the Bear telling you, You can prevent forest fires. And a lot of
this fire suppression led to more fuels. And so in 1988 I can remember the giant fires
in Yellowstone National Park. And so we have to adopt a more sustainable way of managing
fires. Prescribed burns in certain areas to remove some of the undergrowth is an example
of that. Now tree plantations, and you know it is a tree plantation because you see all
these trees planted in straight rows, are a great way to harvest lumber but are not
great of the biodiversity of the forest. And a lot of the forests are owned by us. They
are public forests. So if we look at the US Forest Service in certain states, especially
those out west, it is a high percentage of the land that is in these national forests.
And so their goal is to not only protect that lumber but also protect recreation and biodiversity
in that area. Now are they doing a good job with that? Some people would say they are
doing all three but maybe in that order. That they do not have enough emphasis on protecting
the biodiversity of the forest. As we move on to rangelands a common idea is this Tragedy
of the Commons. It was put forth by ecologist Garrett Hardin and it goes like this. It is
this imaginary situation. Imagine we have two ranchers, they have a bunch of cows. And
there is a public area next to them. We will call it a commons. No one owns it. It is owned
by everyone. So one of the ranchers will put a cow out there. And let’s say this has
a carrying capacity of four cows. Only four cows can live on this area. Well another rancher
might put a cow out. And he will do the same and he will double it and then all of a sudden
we have too many cows on the commons. We have overgrazing and now it is bad for everybody.
So how do we solve the problem? Well one way to solve it is to give them ownership. If
they each own a portion of that land they are not going to overgraze it because they
want it to be productive into the future. So they would only put two cows on each one.
Or the government could come in and say we have limits. So each of you two ranchers are
limited to two cows on that area. And so lets see how that is played out in the US. So rangelands
are areas where we can graze cattle, sheep, things like that. And generally they are areas
where we cannot necessarily grow a lot of crops and so we are able to harvest energy
from that area. If we graze too much we have over grazing. We are depleting the producers
and a lot of those times they will not come back. We can also have deforestation. So this
is not in the US, but if we are looking down in Brazil this is deforestation in the Amazon.
We are cutting down trees. Now a lot of those soils cannot grow crops and so what happens,
about 90 percent of the deforestation in Brazil leads to cattle grazing on that area. And
if we have a combination of these two things, overgrazing, deforestation, it can lead to
desertification. This is the Gobi Desert and you can see that it is growing. And it is
hard once a desert is formed, we cannot go back to having those soils again. So let’s
see how this played out in the US. So we used to have what was called open range. And so
anybody could graze their cattle on it. They would use brands to figure out which was their
own cattle. But over time Tragedy of the Commons brought forth this idea of over grazing. That
combined with big winters, this is a picture of Charles Russell of the winter of 1886,
so so many of those cattle died. We also had the advent of barbed wire so we partitioned
certain areas out. And so in 1934 the Taylor Grazing Act was put forward, signed into law
by Roosevelt. And it established these areas, especially out west, where you could graze.
You could get a permit and then you could graze your cattle on that area but they could
put limits to that grazing. That eventually folded into the BLM. And if we look at how
much rangeland we have in the US it is going to be this light yellow area. It is large
portions of the US. And so you are buying a permit and you can graze your cattle there
and also on US Forest Service land as well. Now what are some problems with that? The
fees do not make up for how much it costs to administer this land. And so in 2006, I
think it was seven times the amount of money to run the BLM as they were getting from these
grazing fees. And so some people say those fees are too low. And also they are protecting
the grazing land but are not protecting the biodiversity of the environment. And so if
we revisit that idea of the Tragedy of the Commons with these two imaginary ranchers
and this common area, you can see that private ownership is one way to solve it. Government
intervention is another way to solve it. But Elinor Ostrom, an economist who won the Noble
Prize said this is all imaginary. These are imaginary ranchers that cannot talk to each
other. And if you look out in the world there are lots of areas where we are sharing a commons,
the Masai of Africa are a great example of that, where they are able to graze their cattle
and do that sustainably. And that brought forth this idea of Ostrom’s law, a resource
arrangement that is working in practice can work in theory. And it allows us to take a
better look at this whole idea of the Tragedy of the Commons. So did you learn the following?
Could you pause the video at this point and fill in all of the blanks? Let me do it for
you. Land management of forests for lumber and rangelands for things like cattle. It
should be renewable. The threats to that are old growth forest, forest fires, tree plantations.
Remember over grazing, deforestation, can lead to desertification. A lot of this is
private but we also have public ownership. US Forest Service of the national forest.
And then we have these federal rangelands that are administered by the BLM.
And I hope that was helpful.
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This post was previously published on YouTube.