[MUSIC] Alpine plants are potentially sensitive to climate change, especially in increased summer temperature. Studying the responses of alpine plants to recent changes requires reliable historical records, and then repeated observations over time, using consistent field methods, and taxonomy. These sorts of re-sampling studies have been most commonly conducted on mountains in the European Alps and in Scandinavia. In 2001, the Global Observation Research Initiative in Alpine Environments, or GLORIA project, established an international long-term monitoring program. And site-based network for monitoring high mountain vegetation and its biological diversity. The program has grown to more than 120 sites around the world, distributed from the poles to the tropics. One general pattern that's been observed in the past decade is that species richness on mountain summits has increased. And that species including grasses, dwarf shrubs and low shrubs, are moving upslope. On all mountains surveyed, nearly 70% of the species that show a detectable change in their upper altitude range limits between surveys have shifted their range limits upwards. In view of projected climate change, these observed shifts in species distribution suggest the progressive decline of cold mountain habitats and their biota. These floristic changes detected in mountains appear to be a response to the combined effects of changes in precipitation and temperature causing changes in the extent and duration of snow cover on some of the areas. Mountains that have experienced the largest increase in summer precipitation have the lowest proportion of species moving upwards. And many species associated with long-lasting snow in spring are ascending. The rates of change can be quite dramatic. For example, in the mountains of the southwest Yukon, measured rates of increased shrub cover are about 5% per decade. Suggesting a fairly rapid shrub advance over the next 50 years, especially if growing conditions remain suitable. These observations suggest that climate change is affecting the elevational ranges of alpine plants. But the link between range shifts and climate change is more complex than a simple response to temperature increase alone. 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. Where we have woody vegetation. That's the main prediction, is that more woody vegetation, be it trees or shrubs, will be found further up the slopes and into what's now tundra. >> Determining how rapidly mountain environments are changing, and why, is obviously a big challenge. One approach has been pioneered by Dr. Eric Higgs at the University of Victoria, and involves the systematic analysis of mountain landscapes by comparing historical and contemporary photographs. The Mountain Legacy Project is a long term study of landscape, ecological and cultural change in the mountainous regions of western Canada. Here's Eric Higgs on the Mountain Legacy Project and the sorts of things he and his team are learning. >> The Mountain Legacy Project is based on an extensive collection of historical survey images that were conducted throughout the mountainous regions of Canada. It's the world's largest systematic, comprehensive collection of mountain images, historical mountain images. They are exquisite images because they were done to survey standards, to create the first topographic maps of the mountainous areas of Canada. We've been going back since 1998 and repeating some of those images from exactly the same locations as the original surveyors stood. 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. >> Here's a great example of the kind of interdisciplinary work Higgs and his team are doing. Take a look at series of survey images from the early 20th century as well as their recently repeated counterparts. Paired images like these, these are showing the mountain landscape of Jasper National Park, can tell us much about changes in vegetation composition and distribution. Using a quantitative approach for assessing relative vegetation change, research in this area found a shift towards late successional vegetation types and an increase in canopy closure in coniferous forests. Grasslands and open forests decreased in extent. These changes in vegetation patterns can be largely attributed to shifts in the forest fire regime. Today we have more trees, and they're thicker trees. And this has come about in large measure due to the repression of forest fires over a century of land use practices. For a very long time, fire was seen as a bad thing. It was seen as a blight on the landscape. And over the long term, fire suppression has left us with what may seem perhaps like a beautiful and a healthy forest, but in reality, forest fire suppression has placed these forests at risk. The implications of these changes include decreased habitat diversity, increased possibility of insect outbreaks, and potential for future high intensity fire events. Fire is a natural disturbance agent that has helped create the landscapes we see in many mountainous areas. Fire produces a mosaic of plant communities of different ages and species composition on the landscape. Areas where the forest is completely consumed by fire are interspersed by patches of unburned and lightly burned forest. Periodic fire reduces the amount of accumulated fuel on the forest floor, such as woody debris, dead trees and forest floor litter. These lower intensity fires reduce the potential for extremely large hot fires, which can damage soil and result in increased erosion and the loss of soil fertility. Some montane habitats, like grasslands, have been subject to frequent fires over many centuries, and are considered fire dependent. These ecosystems require fire in order to restore and maintain ecological integrity. While fire has more obvious influences on plant communities, the effect of fire on wildlife varies accordingly to intensity and duration of the fire, season of burning, and the ecosystem that is burned. In general, fire increases the abundance of shrubs and grasses that herbivores such as elk and deer feed on. Fire also results in increased availability of berries that form an important part of the diet for grizzly and black bears. 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. >> Another strategy for protecting biodiversity is the reintroduction of species to places where they've disappeared. For example, plains bison have been absent from Banff National Park since before its creation in 1885. The planned reintroduction of a small herd on the park's eastern slopes, a remote wilderness area that provides a suitable habitat, will contribute to conservation and recovery efforts as well as reconnect Canadians to this iconic species. Several successful conservation initiatives over the past few decades have laid the groundwork for the bison reintroduction. These efforts have included a prescribed burn program to restore productive grassland habitats, maintaining healthy populations of natural predators, wolves and grizzly bears, and recent success in reducing the elk population to closer to historic levels. Thereby reducing the potential for competition between elk and bison for food. As well, the construction of wild life fencing and crossing structures along the Trans-Canada Highway, which we discussed in the previous lesson, has greatly reduced the risk of wildlife-vehicle collisions. Karsten Heuer is the bison reintroduction product manager for Banff National Park. Let's hear more about some of the challenges he and his team have been working on. So here we are in Banff National Park. I'm with Karsten Heuer, the Bison Reintroduction Project Manager with Parks Canada. Karsten, when's the last time I would have seen a bison here in Banff National Park? >> Would have been a long time ago, David. Well over 100 years, probably back in the 1870s. >> And why did they disappear? >> Well it's the same reason they disappeared from the plains, they were overhunted. >> I see. 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.