2:46
Although alpine habitats are often thought of as natural or
pristine, they're being increasingly subjected to environmental stressors,
depending on their location and environmental history.
Many factors influence the rates and trajectory of change, including nitrogen
deposition, land use, introduced invasive species, ski development,
and overexploitation, leading to erosion and landscape degradation.
Given these direct human impacts, and projected impacts of climate change,
the long term future of alpine plant communities remains very uncertain.
Uncertainty is something that we have to live with, but
long term observations are leading to some very consistent conclusions about
increases in trees and shrubs at higher elevations in many mountain environments.
Here is Dr. Greg Henry from the University of British Columbia.
>> For alpine tundra systems, the way they are predicted to change.
Because these are cold systems.
If they warm up, they're going to change.
But the change is going to depend on where that system is,
and the kind of initial conditions that those systems have.
And which, again, is going to depend on where exactly they are.
In relation to their position on the planet and how much energy they receive.
So, tropical mountains versus Arctic mountains, for example.
And so they will change.
And one of the major changes in the plant communities of
our alpine systems would be the increase in tree growth.
And in areas where we would say there's alpine tundra, and you find those
areas all over the world, in all mountains that are high enough, higher, of course,
as you get closer to the equator, lower when you get closer to the poles.
6:01
We can learn so much from time series images.
We can understand the dynamics of landscape change over the last century.
Most of the historical images date from the late 19th and early 20th century,
so there's lots that we can study.
The limitation, perhaps, is that we only have two points in time, at least so far,
but there's a lot that you can tease out inferring the nature of change.
But, it's not just the time series that matters, we can go back to
the historical images and we can infer what's happened in the landscape prior to,
say, the 20th century.
So they're really powerful in lots of ways.
The other, I suppose, temporal dimension, is that we can use the past,
the present and infer what's going to happen in the future, too.
So we can model out the future based on what we know of the past.
9:34
Parks Canada is a world leader in the use of fire as a method of restoring a natural
process to the landscape, supporting ecosystem biodiversity and health.
Their prescribed burning program is designed to reduce wildfire risk, and
improve park ecosystems.
To give you a better sense of Parks Canada's prescribed fire program,
here's Dave Smith, the fire and vegetation specialist for Jasper National Park.
[MUSIC]
>> Wildfires are a natural part of the environment in places like
Jasper National Park.
Of course, because there's so many people in places like the Athabasca Valley where
we're standing right now, we can't just allow wildfires to happen.
However, we still want put to fire back on the landscape.
So for that reason we have prescribed fires.
Prescribed fire is when we actually burn the forest.
Now we don't just go out and
burn the forest when we want to, we have to make sure that we're in a situation
where the forest is going to burn the way we want and need it to.
So that we can keep some control of how big the flames are and
how much of the forest burns.
Fire is a good thing.
When we burn, we burn using a whole variety of techniques.
The one that we use in order to burn large areas is the helitorch.
[MUSIC]
In a helitorch basically what we do is fly over, we drop gelatinized
fuel onto the forest floor to create a mosaic of burned forest.
[MUSIC]
Fire is a natural process that is very important to the maintenance of forest
health in Jasper National Park.
If we look back into the past,
we see there's always been fire on the landscape here.
And as we go into the future, we have to maintain fire.
The best way for us to maintain fire in many parts of this park is through the use
of prescribed burns, and we plan to do that well into the future.
13:31
So Karsten, what are some of the challenges of reintroducing bison back
into Banff National Park?
>> Well, we're dealing with this migratory animal.
Bison like to move, we all know that.
And yet
we're having to try to reintroduce them only to a section of Banff National Park.
And also make sure they don't leave the National Park.
So we're doing things like putting up some drift fencing that's supposed
to be permeable to wildlife but still be able to discourage bison from leaving so
there are some challenges in that as you can imagine.
>> Sure.
>> And then on the social side, bison haven't been here for
over 100 years, and people aren't used to the idea of them being around
We all can coexist with grizzly bears and rutting elk and all those things.
We've proven that.
And bison aren't going to be any more challenging.
But it's just the notion of this is something I don't know.
I don't know how to act around it, I'm not sure what it's going to do.
And there's just a mental shift that people have to have.
They have to give up a sense of control, I think.
And it's going to be fine.
There's lots of places where people and bison do coexist, but it's just that leap.
And so that's just going to take time.
>> So Karsten, where's the best habitat for bison in Banff National Park?
>> Well actually, David, we're standing out overlooking here at Vermilion Lakes,
in the Bow Valley, right near the town of Banff.
And this is actually where the most archeological finds have been made of
bison bone and skulls.
Down in the town of Banff, a lot of times when they dig up a new sewer line, or
building a new building, they're actually excavating bison skulls, so
that's pretty cool.
So we know they were here, and yet the Bow Valley's a different place now.
it's busy, it's the Trans-Canada Highway,
the National Railway, 4 million plus visitors a year.
So we're actually going to start in a place that has as good habitat, but
it doesn't have as many people.
It's about 40 kilometers north of here, the Panther River Valley.
It's a two day's walk from the nearest trail head to get in there, and
it's very grassy.
And so that's where we're going to start with just a few animals, we're going to
start with about 30, and it'll allow us enough time to get used to them.
And for them to get used to their new home before potentially many years down
the road, they may come down into the Bow Valley again here.
>> Sure, what do we know about their predators?
>> Well, this is the really, really cool thing about this project is,
unlike a lot of places where plains bison have been brought back,
here they actually still have their predators.
So wolves, cougar, grizzly bears will definitely go after some of their calves,
and then we have the whole range of scavengers as well.
From the wolverines right down to crows, and ravens, and magpies.
But that's super important that they have that pressure, that tension, if you will,
in their lives that constantly has them looking around and running.
And that's, Aldo Leopold said it really well, he said,
where would the deer be without the wolf to have whittled its leg?
And the bison, in order to be robust and continuing to evolve,
they need that natural selection pressure that predators provide.
And that really is one of the unique things about Banff National Park and
bringing them back here,
is we can contribute wild bison back into the global conservation population.
>> Now I know you've also worked very closely with local communities,
especially the Stoney Nakoda and Sitka First Nation people.
What's been their role in this project?
>> Right from the start they've been involved.
And they're very keen on this project, so
it's been a real pleasure working with them.
This summer, for instance,
we're going to be helping them conduct a ceremony that will welcome the bison back.
So we're going to take them out to the exact place where their hooves will first
hit the ground again in January.
We'll do it this fall when the weather's a bit nice, and to prepare,
spiritually, the place for the return of the bison.
And then down the road, there will be employment opportunities,
there maybe some opportunities for First Nations to actually harvest and
take some of the meat and other things on bison that they use.
>> Yeah, well, this is a really exciting project.
Good luck with it.
>> Great, yeah, thanks David.