Episode 6: Climate Change and the Future of the Boundary Waters

How will climate change affect northeastern Minnesota? Dr. Lee Frelich discusses how ecological changes brought on by forest succession, species migration and warming waters will drastically transform the Boundary Waters.

If you want to know what climate change will do to the wildlife, trees and vegetation of the BWCA, don’t miss this special episode.



How will climate change affect northeastern Minnesota? Dr. Lee Frelich discusses how ecological changes brought on by forest succession, species migration and warming waters will drastically transform the Boundary Waters.



Dr. Lee Frehlich  00:01

Two springs in a row like this, wipe out all the boreal forests from Minnesota all the way over to the Atlantic Ocean in one fell swoop. And of course, if you shift the vegetation you shift the wildlife or so yeah, moose being placed by here is something that anyone can understand.


Chris Knopf  00:23

Hello, welcome to the Friends of the Boundary Waters Podcast. I’m Chris Knopf, the Friends Executive Director. Thank you for joining us. It’s Thursday, November 18. And this is our third and final podcast on climate change. On today’s podcast, we talk to Professor Lee Frehlich, who is the Director of the University of Minnesota’s center for forest ecology, and is one of the leading experts in the world on boreal forests, which is the type of forests in the Boundary Waters. Dr. Frehlich is also a former board member, the friends and we are grateful for his many years of service, Dr. Frehlich paints a shocking picture of how climate change is already transforming the force of the Boundary Waters. Dr. Frehlich also explains how we can reduce the most catastrophic changes these forests by taking action now. For more information and for resources presented in this podcast, please visit Friends-BWCA.org. Here’s Dr. Frehlich.


Dr. Lee Frehlich  01:21

Thank you for that introduction. And we’ll start with a broader context before we zoom into the Boundary Waters, namely the massive 200 year body of scientific data that we have on climate. And Fourier, for example, discovered that greenhouse gases exist in the atmosphere way back in the 1820s. So we’re already looking at the 200th anniversary of the beginning of climate change science here. There are other sciences like Tyndall, who advanced that more in the 1860s and Dr. Seuss here. This is not the same Dr. Seuss, you’re probably thinking of but this is Dr. Hans Suess who proved that excess co2 in the atmosphere actually came from fossil fuels way back in the 1950s. Because it has a unique isotopic signature compared to natural sources of co2. And then the really big player is Arrhenius, Swedish scientist, and although he won the Nobel Prize for discovering that salt dissolved in in water conducts electricity, and that chemical reactions go faster at high temperatures. His real interest was in carbon dioxide and climate change. And in fact, he did the first projections of what would happen to the mean temperature for the world. If we doubled the co2 content of the atmosphere. It took him two years to calculate it using paper and pencil Of course, I was free computer. And he published those projections in 1896. And they still stand today. Our fancy computer models that we have today are pretty much the same as what he projected around a four degrees Celsius or seven or eight degree Fahrenheit increase in mean world temperature if we doubled the co2 content in the atmosphere. Oh, there we go. So we also have triggering analyses from boreal forest, for example, this is from the Northern Ural Mountains in Russia. And there are trees there that are over 2000 years old. And they are at a far northern edge of the range of where trees can grow. If you go any further north, it’s it’s Arctic tundra. So they’re, they are limited in their growth by temperature. And as you can see, just in the last few decades, the growth is faster than it’s been in 2000 years and that is a response to the warming temperature. And then this is a composite climate change for the last 10,000 years using tree rings, sediment cores, cores from ice and glaciers, a lot of different types of evidence synthesized here and it does show the the peak of the interglacial about six, six or 7000 years ago when it was fairly warm and then it shows for the last 5000 years a natural cooling trend and in the red line on the very right side is the recent reversal of the natural cooling trend due to fossil fuel burning, and we’re now of course warmer than we were 7500 years ago at the peak of this interglacial. And then if we look at temperature increase on the timescale of several decades, this shows the actual instrumental record. In other words, thermometers at weather stations, and if you go back to 1880, that’s the first time that there were a sufficient number of weather stations around the world to get a really good estimate of mean world temperature. And so you see it year by year on this graph. And if you add 2019, and 2020, and there they are even higher here on the on the right side, but you can see it’s an upward trend in recent decades, and it’s getting steeper and steeper. So we do have very significant warming that has already occurred. And it’s going to continue to occur, maybe a lot, or maybe not so much depending on alternate scenarios that I’m going to tell you about.


Dr. Lee Frehlich  06:17

In those alternate scenarios on this graph, where the vertical axis here is carbon dioxide content, the blue dot is about where we are, we’re slightly higher now, because that was 2008. But are by the year 2100, are we going to the green dot, which is 550 parts per million, and we’re at about 410 parts per million right now. Or are we going to go on a high emission otherwise known as business as usual scenario and the 900 parts per million. And those two alternate scenarios are hugely different from each other, whether we follow this reduced emissions scenario is tremendously important for the future of the world, and especially the Boundary Waters. When you see here, the co2 content of the atmosphere for the last 800,000 years and the ups and downs there are that you see are the 100,000 year glacial cycles, which are driven by natural phenomena, and that varied from 180 to about 280 parts per million. Now, we’ve already shot up to 400 parts per million. So that’s as high as it’s been in the last 2 million years. Actually, if you go back even further than this, find a time when it was as high as it is now. And then these are temperature projections for the alternate scenarios by the year 2095. So the reduced emission scenario, like they are talking about in have been talking about in in Scotland, over the last two weeks. And four, they really highly reduced emissions where we reduced by 80% or more our use of fossil fuels, we would only warm up by about one degree Celsius or two degrees Fahrenheit, maybe three degrees Fahrenheit here, in the middle of North America, there would make the Twin Cities here about the same as Des Moines, Iowa. Or for the business as usual, on the left, it would warm up by seven or eight degrees Fahrenheit, or Celsius, excuse me, which is around 12 or 13 degrees Fahrenheit. And that would make us as warm as the central part of Kansas. And why do scientists really care about this issue? Because if you look at the great extinctions in the history of the Earth, such as the great dying, which was the end of the Permian, 250 million years ago, four out of the five great extinctions are associated or were associated with higher co2 content in the atmosphere in those cases due to natural phenomenon. And that led to acidification of the ocean and mass extinction on the planet. And so the same thing could happen now except it’s humans that are taking the place of volcanoes in terms of raising the co2 content of the atmosphere and we could create another mass extinction which might end up including ourselves and so that’s why scientists think it’s important. There are a number of tipping points in the world and one of them that is officially designated Is the boreal forest in Central North America and the Boundary Waters is on the very southern edge of that. So it’s very important that we go on the low emission scenario, otherwise massive swathes of his forests could die. And that would put a huge amount of co2 in the atmosphere. And that would negate our efforts to reduce the amount of co2 in the atmosphere. So it is one of the world’s tipping points, which we live at this point.


Dr. Lee Frehlich  10:39

So boreal forests, what are they, and this is a map of them. They are the coldest forests on the planet. They are just south of the Arctic tundra. So at the northern edge of the Boreal, that’s the coldest climate that any tree can possibly withstand. They’re made up of spruce and fir, birch and Aspen. There are also some species of pine and Larch, and it does dip down into the arrowhead of Minnesota. So we have a little slice of that boreal forest in Minnesota. So basically, it’s a cold climate, very cold winters, long winters, short winters with cool, short summers and cool temperatures during summer is characteristic of boreal forests. So extreme winter cold. Most of the temperate species like maple and oak, can go down to about 45 below zero, they actually deep super cool. In other words, they have anti freeze like substances in their sap. And it can go down to 45 below zero without freezing. And if it doesn’t freeze, it’s not going to kill the cambium, which is the living wood, which is just under the bark. So it actually does sometimes get that cold in northern Minnesota during the polar vortex, ie the end of 2019. It was 56 below zero and at Minnesota, for example, but it doesn’t get that cold as often as it used to be you can also get a boreal forest from having summers that are too cool or too short for temperate species like maple and oak. And that happens in places like Grand Marais on the shore of Lake Superior Isle Royale or on the Door Peninsula in Wisconsin where cold water in the Great Lakes of wells alongshore and creates very cool summers and it actually doesn’t get very cold in the winter. And that can just throw the competitive balance to boreal species. So either extremely cold winters are short, cool summers or both and make a boreal forest like we have in the Boundary Waters. And you see that before as they’re at Tettegouche rest stop on the North Shore which is a very good example of a boreal forest. So there’s the the area we’re interested in. So boreal forests with jack pine, white spruce, black spruce, paper, Birch, Aspen are the main species in our boreal forest. And there is a bigger picture showing mostly balsam fir and some white spruce here and a lot of paper birch on the North Shore. So what about our regional temperature projections now for a reduced emission scenario, which is the bottom row and high emission scenario, which is the upper row and then from left to right, it goes from now to mid century and late century. So in the low emission scenario, this one happens to be in degrees Fahrenheit, because Don Wobbles, and I use this slide in Washington, DC, and there isn’t any celsius in Washington DC. So anyway, it’s Fahrenheit, so five degrees warmer in summer.


Dr. Lee Frehlich  14:11

And I decided to show summer mean temperature because it’s so critical for forests. Here instead of annual mean temperature, winter temperature. So summer temperature is the most critical, so five degrees warmer in summer, making us about the same as dewine, or in the upper scenario, the business as usual 13, 12 or 13 degrees warmer, which should make the Boundary Waters like Southwestern Minnesota or maybe unlike Omaha, Nebraska, would make the twin cities like the middle of Kansas. So what’s the difference between those two scenarios? Well, we’ll find out over the next few minutes. With that business as usual scenario we would expect the ranges of most tree species to move north by about 300 miles. So for balsam fir the map on the left, the red areas indicate very high abundance. The blue line shows the absolute edge of the range where you would find any balsam fir at all. So that’s our favorite Christmas tree and without high emission their business as usual scenario would basically exit Minnesota along with black spruce, whites, spruce paper, birch would have similar results as wood, balsam poplar and a few other tree species. So that would be that basic impact of we have so many tree species where the southern edge of their range is here, and it’s so it’s just barely cool enough to keep those species right now. And that could change dramatically. So I had a PhD student Nick Physikelly, who studied the interactions between boreal and temperate species, he wanted to know what makes the difference between a boreal forest of spruce and fir and a temperate forest of maple, oak and basswood. So we visited all these sites that you see the black stars and the red triangles. The red triangles just had more detailed data collected. Otherwise, they were the same. And all of these are gradients from places with very cool summers, where it’s mostly spruce and fir and just a little bit of maple and oak and then the either the Western or the southern edge of each transact is areas with warm summers, where it’s mostly maple and oak and just a little bit of spruce fir, but on every one of these sites, maple and oak and spruce and fir are growing together side by side. So we looked at the growth rates of the species, the ring width, as well as the height growth of this species shown here, balsam fir, white spruce, red and sugar maple and red oak. And basically, there’s a crossover point here between 64 and 65 degrees Fahrenheit for mean summer temperature. It’s cooler than that the boreal species grow more, it’s warmer than that the temperate species grow more and they grow about the same right in the middle there. So if you look at a place like Duluth from 1960 to 1990, summers were cool enough that clearly spruce and fir would outgrow the temperate species. At this point, they’re close to that crossover point. And in the near future, it’s going to be warm enough that maples and oaks have very similar data data, even though not shown here. So maple and oak would be able to outgrow spruce and fir and therefore gradually replaced them in the forest. Just because of the summer temperature warmed up one or two degrees Fahrenheit. This is a state park in Wisconsin that has boreal forest. It’s white spruce, balsam fir and white cedar in this case. So very similar to what you would find on the north shore in the Grand Marais area. And in 1979, you could not find a maple tree here, and I revisited in 2016. And there’s a sugar maple tree on the right, growing right in with the balsam fir in the understory and growing about the same in height each year. So this area formerly was too cool. And for the temperate species, and now it’s right near that crossover point. And so they’re each growing about equal. And so the overall lesson here is temperate tree species are invading the understory of boreal forests in cases where the boreal and temperate species are growing next to each other. If you look under those boreal trees, there will be temperate tree seedlings underneath, and they are growing as well or better than the boreal seedlings.


Dr. Lee Frehlich  19:11

They have not had time to replace the boreal species yet they haven’t made their way up through the canopy. But it’s now warm enough yet to kill the boreal forests. But so the mix zone where temperate and boreal species are mixed is becoming wider right now. But the the temperate species could easily replace the boreal species as we move forward, and even more so if we go on the business as usual trajectory. disturbances can interact with this transition from boreal forests to temperate forests that might occur. This is the big blowdown of 1999 in the Boundary Waters notice on the after picture on the right after the blowdown the big trees are all knocked down. But It’s still green. Because there are millions and millions of balsam fir and spruce and white cedar seedlings that were underneath the big trees. It’s still a boreal forest to find this picture is taken it’s just small boreal trees instead of big boreal trees. However, now that some of the boreal forests are invaded by temperate species like maple and oak, like you see in this picture, the red is red maple. In the understory here, the birds are dying, they’re in this picture, but even if they weren’t dying, if a big windstorm were to come and level the birch and the Aspen in the spruce here, there could be an instant conversion to temperate forests following the windstorm instead of having it stay Borio like after the 1999 blowdown so disturbances can definitely accelerate this transition more than faster than it would occur just with the maple trees and oak trees slowly making their way up through the canopy. So here are the boreal species. Black and White Spruce balsam fir, jack and red pine, quaking aspen, paper birch, these are the most common in the Boundary Waters. And how about warming up the summers and not only the maple that I showed the red maple but how about some elm borough, basswood, Hickory hackberry. In other temperate species, there actually is already a little bit of burr oak in the Boundary Waters and some basswood as well. And they in red oak, northern red oak, they’re limited to very small locations, mostly on the tops of hills or south facing hillsides. But our studies indicate that their seedlings are spreading from those locations and that their seedlings are widespread underneath the boreal canopy at this point, with a relatively small magnitude of warming that has already occurred. So that’s boreal versus temperate forests. What about any type of forest at all? In Minnesota, we are right at the edge of not only the boreal and temperate biomes but grassland or the very biome, so it’s a unique place, we have three biomes coming together. temperate forests, boreal forest and grassland, we’re very, there’s there are only a few other places like that in the world, one of which is northern Kazakhstan, for example, that have these three biomes coming together about what makes the difference between forest any type of forest whether it’s boreal or temperate versus prairie, and you see the original, original meaning of the time of European settlement. very porous border on the left, and another graduate student, Nick Downes, who’s now on the faculty of the University of Wisconsin superior, studied that for his PhD and discovered that border aligns approximately with a zero balance in water. In other words, where precipitation and evaporation are exactly equal, the water balance is zero. The green and blue areas on this map have an excess of precipitation over evaporation. So they’re wet enough to have for us and then the brown areas are getting to the zero water balance and the darkest brown is actually negative. So there’s more evaporation and precipitation.


Dr. Lee Frehlich  23:57

So that what is what determined where the very forest border was. And the question is, where will that that zero balance and precipitation and evaporation move in a warmer climate for the low and high scenario? While we’ll see that in a minute.


Friends of the Boundary Waters  24:17

We’re going to take a short break here to ask, “Do you need help planning for your next Boundary Waters trip? Visit our website at Friends-BWCA.org, where you’ll find amazing trip resources, route maps, articles and free guides to prepare for your next BWCA adventure.


Dr. Lee Frehlich  24:37

And some of the things that can happen along the prairie forest border is what has happened already out in Alberta and Saskatchewan. And you see here a summer mid summer picture of an aspen forest right on the edge of the prairie forest border and they are dead because of a drought that occurred in the early 2000s. So that type of thing could happen further east as the climate continues to warm in addition to that, when trees are under drought stress, which they are wet and they’re at the southern edge of their rain, you know starts to warm up more than they can tolerate, they’ll still have drought stress, they will not be able to defend themselves against insects as well as they could. With a cooler, wetter climate, there will be more forest fires more diseases. So those just like the wind storms could help the temperate and boreal forest boundary move. As the climate changes, these things could help the the berry forest corridor move because they would work against a lot of different tree species. And there we have these weird period periods of extreme cold and extreme warmth. That last several weeks or even a few months of time, like we had from June through October this summer, for example, the warmest summer recorded in the history of Minnesota. But you might also remember March of 2012. Winter, it was in the 80s for a whole week in mid March. We have 15,000 record high temperatures set in the United States. We have magnolias in bloom here in the Twin Cities on the 27th of March that affect the boreal forest as well and help push things along. Well, yes. So phenology is the timing of biological events. For example, when trees open their buds and leap out in the spring. And with that extreme warmth coming in March, a lot of trees in the Boundary Waters and then in adjacent Ontario in the lower picture did come out of dormancy too early, and then it got cold again. And so the the needles all died. You can see a stand of balsam fir and Jack Pine in the upper left there one of our study sites in the Boundary Waters and then the vast expanse of brown spruce trees there in Ontario. These trees did recover because we had several normal years with normal temperatures and higher amounts of rain in 2013 through 2019. And they recovered. But two springs in a row like this could wipe out all the boreal forests from Minnesota all the way to the Atlantic Ocean in one fell swoop. And with the business as usual scenario by 2095 and average spring would be like the spring of 2012. So there’s some added complications there. So warmer summers allowing maple note to replace boreal trees wind, maybe accelerating that process. Even drought stress and insect infestation due to lack of extreme cold that might otherwise kill the insects and very early springs could all work against a boreal forest and help converted either to temperate forest or to grasslands and savannas which were grasslands with few scattered trees.


Dr. Lee Frehlich  28:27

So here’s the summary of, of what we found for what controls where these biomes are. And again, the temperate forest with warmer summers boreal forests with cooler summers on the upper bar. And then the climatic moisture index forest with wetter climates on the left and prairies with drier climates with negative water balances on the right, what if you just put the map this out and just look at the whole landscape and turn it into little pixels, which in our case are one kilometer square, which is like about 40% of a square mile in size and calculate the climate of each and put it on a map? Well, this is what you get. So if you look at the left, that’s the current climate envelopes that support boreal forest which is the blue and you see Northeastern Minnesota there, including much of the Boundary Waters has a purely boreal climate at this point and then that kind of minty green colors where you have boreal and temperate mixed together and then the yellow is the is the broadly for the temperate forests there would be your oak, maple and basswood and then the brown is very so the prairie forest border is actually moved to the west. Since European settlement you might remember it came across Minnesota Northwest to south east at the time of European settlement, and that’s because in the early phases of climate change, we’ve gotten more rain. But evaporation has not gone up as much as rainfall, at least until this summer. Now that definitely reversed this summer, whether that will continue as a pattern remains to be seen. We had way more evaporation than rainfall this particular summer. But if you look over the last three or four decades, on average, it’s been Rainier and not a big increase in evaporation. So very climates have actually moved off to the west. But we think that will reverse as climate change progresses. So looking at the low in the upper right, the low warming scenario, prairies would push back in a little bit of boreal recede a little bit as with the mixed boreal and temperate but it would still look like Minnesota. For the business as usual, or the high warming scenario in the lower right, you can see that the the prairie forest border would indeed move about 300 miles and only the north eastern tip of the arrowhead would have forest at all. And that would not be boreal forest, it would be maple and Oak Forest. Next to a savannas in the Boundary Waters. And so Minnesota would be the new Kansas 90% of Minnesota would have climates that would support berries, which is where the the quote from me in the Washington Post, that we have a perfectly good Kansas now. And we don’t need a second Kansas in Minnesota. So that’s where that quote came from was me speaking to a reporter at The Washington Post and making a statement like that is how to get feedback from everybody in the world as I discovered. And I can tell you what type of feedback but you can imagine, use your imagination. So let’s look at a climate analog. Can we find a place that’s like the Boundary Waters, which is the blue star Oh, it looks like it’s slipped into the medical there. But anyway, the Boundary Waters and adjacent wedeco Provincial Park, which have essentially the same climate, and we find an area that’s like that right now or the summers right now have a climate like they might have say in the year 2060 or 2070. And that is the orange star which is near Granite Falls Minnesota. So you can go to Granite Falls and you can look and see what is the vegetation like as the name Granite Falls implies there, there actually some genetic rock outcrops there. So even the physiography of the landscaping the substrate in terms of rock is similar to the Boundary Waters so it’s a good analog for the future of the Boundary Waters. So here’s the Boundary Waters. This is a black spruce and paper birch forest, growing on 2.8 billion year old granite in the Boundary Waters.


Dr. Lee Frehlich  33:29

And here’s what happens if you take that in you look at very similar physiography but the only difference is summers are about eight degrees Fahrenheit warmer. We get this which is nice outcrops natural area near Granite Falls and you can see clumps of oak trees and patches of prairie here mixed together on very similar rock type and soil conditions as you have in the Boundary Waters. And again, the only difference in these two pictures is about eight degrees Fahrenheit and mean summer temperature books and of course if you shift the vegetation you shift the wildlife all wildlife depends on the vegetation that lives in it depends on it in many, many ways. So if you change the vegetation you change the wildlife. For example, links in boreal forests and Bobcat in temperate forest or very types of environments. Moose in the boreal forest deer in the temperate forest, and for birds, you could pick many, many examples. But I happen to oh, there’s a mistake here. Black back woodpecker should be the upper one and red bellied woodpecker should be the lower one. So just (unintelligible) in your mind try to reverse those labels. So Black back woodpecker replaced by red bellied woodpecker black back woodpecker is one of my favorites in the Boundary Waters. And there are already red bellied woodpeckers that have been seen in the Ely area. So, deer has moved into Northeastern Minnesota, and so are bobcat so I actually made this slide for Amy Klobuchar when she was going to give a speech on the floor of the Senate, and this was probably five or six years ago. And so it’s my estimation of the level at which the US Senator senators can understand climate change. So yeah, moose being replaced by deer is something that they can anyone can understand. So we have those alternative futures. For the Boundary Waters, it can stay boreal, maybe a little bit of intrusion of the temperate forest, but would still have the boreal conifers present for the reduced emission scenario. And actually, white pine would do better than it does today. It’s a little bit on the cold side for white pine today, it would actually do better if it warms slightly and stayed just slightly warm. Whereas the business as usual scenario would lead to widespread grasslands and savanna and some oak forests and Boundary Waters. And you see David Luke’s photo here, he did many photos of iconic scenes in the Boundary Waters, and then digitally race the vegetation above the wire and substituted pictures taken in Southwestern Minnesota berries or savannas. So you see the boreal forest. That’s there at Duncan Lake, and it’s reflected in the water. But above the water line is, is an oak savanna. So that’s another way to visualize what might happen in the future. So that’s all I plan to say. Oh, no, that isn’t all I plan to say. One more slide. Sorry about that. I forgot. How do we solve the problem? Well stop subsidizing fossil fuels which to renewable energy, increase the energy efficiency of our that we use, stop deforestation regenerative agriculture, and eat more plants, which helps regenerative agriculture, more Plant Agriculture and less animal agriculture are all ways to reduce the emissions of co2. And with that, that was all I have planned to say.


Friends of the Boundary Waters  37:50

I’m a friend, I’m a friend, I’m a friend. We’re friends, friends. Do you want to be a friend of the Boundary Waters, join the movement to fight for clean water and help foster the next generation of BWCA enthusiast today? Connect with us donate and learn more about membership at Friends-BWCA.org.


Maya Swope  38:13

In the chat, we have a question from Susan, who says, Would you please comment on the impact we can have more regionally by making changes? Is it an all or nothing action on overall climate change?


Dr. Lee Frehlich  38:29

Well, every little bit helps every person in every region of the world has to do its part it is a global thing may not only the the entire world as a whole can reduce co2 emissions. But each region of the world is unique. And how you reduce co2 emissions in a given region is unique. Right. So in our case, we do have places where we can plant trees, we do have good alternatives for for energy sources other than burning coal. And so we do have good choices for food sources, for example. And so there’s a lot of different strategies that we can take here. And it varies. You know, if you’re in a desert region, you’re not going to try to reduce co2 emissions by planting forests. So each region is different. And that list of things that I presented, that that really is tailored for our region, we can do all of those things. In Minnesota, and so that’s our part.


Maya Swope  39:41

Great, yeah. Thank you. I see a question from Mike here who says, based on your projections, if we are successful in preventing global warming above 1.5 degrees Celsius, will we see the change to temperate forests that you outlined?


Dr. Lee Frehlich  39:58

Yeah, we will see small changes. So the Boundary Waters would still have pines, it would still have spruce and further there would be some increased sense or some intrusion, if you want to look at it that way of maple and oak into the forests in the Boundary Waters. But it would not be extremely extensive. And we certainly wouldn’t end up with berries or savannas. In the Boundary Waters, we follow that reduced emission scenario. So it’s still a pretty similar to today. So the alternatives are so different in the Boundary Waters, because it’s so close to the biome boundaries of temperate forests, boreal forest, and grassland. And so it’s so much so susceptible to changes in climate because it’s near those edges of biomes. More than most of the world is it made it having those edges makes Minnesota an interesting place. It also makes Minnesota a place where changes could be really big compared to most of the world in terms of our natural resources, and especially the vegetation and wildlife species. But we could still have conifers in the Boundary Waters with the reduced emission scenario.


Maya Swope  41:27

Great, thank you. Yeah. And kind of speaking to some of those changes. Few people were wanting more info about Minnesota as iconic red and white pines. So Libby had asked, how are the Pines expected to do between red and white pines? Is one going to adapt better to warming temperatures? And the other few other folks that kind of had similar questions?


Dr. Lee Frehlich  41:52

Yeah, well, the situation for Red Pine is not good, because we’ve brought in a bunch of exotic fungal diseases that infect red pine foliage. And it’s really hard to regenerate red pine, and it’s more sensitive to a warming climate than white pine. So if we follow the reduced emission scenario, I think we would hold on to some red pine in the Boundary Waters would have a little bit of a tough time white pine would do really well. White Pine naturally has a warmer optimum temperature than the Boundary Waters has right now. And it would grow even better if it warmed up slightly. For the business as usual scenario, neither of them would do very well. But I think red pine is the most vulnerable. And even with reduced emission scenario, we would see some problems with red pine, I’m not sure it would disappear. Boundary Waters would have the best chance of retaining red pine of all the areas within Minnesota and white pine would do just fine with the reduced emission scenario.


Maya Swope  43:06

Right. Yeah. And I see other folks are kind of wondering about other tree species that so if you could talk a little bit more about how these warming temperatures would affect specifically white cedars and tamaracks.


Dr. Lee Frehlich  43:20

Okay, white cedar and tamarack? Yeah, well, with reduced emission scenario, I wouldn’t expect much of a change in white cedar or tamarack in northern Minnesota at all. There is some problem with the warmer winters that we’ve already had with large fetal prising mortality and tamarack. So that problem will continue. But other than that, with the reduced emission scenario, I don’t expect a lot of other problems. And I think those species would do would continue to do quite well. And but of course, again, with a, with a business as usual scenario and the high warming scenario, you know, those species could end up being reduced in the area that they occupy. You know, they like the white cedar wouldn’t grow on south facing Lake shores. For example, it might be too hot and too dry for one. there’d be fewer bogs and fewer places where tamarack would grow. But yeah, the reduced emission scenario would be okay for those species.


Maya Swope  44:32

I see some folks who are wondering kind of, you know, with these changes in species what that means for management. So, I see someone in the chat has said the Boundary Waters forest is now managed only by prescribed fire. As things change. Are their arguments for more management, harvesting planting of species that like warmer temps.


Dr. Lee Frehlich  44:55

Yeah, if we were to go on the business as usual, scenario and it looked like the Boundary Waters is going to become an oak savanna. And there’s just no way you were going to prevent that, then you might as well make it the the best Savanna it can be. And that would mean keeping invasive species like buckthorn out of the Boundary Waters, we might have to facilitate the movement in that case of some of the savanna species into the Boundary Waters, because they’re stuck on little tiny postage stamps of remnant savannas, hundreds of miles to the south in southwestern Minnesota, and they, a lot of those species would have no way to get to the Boundary Waters. So we might have to assist them in making that jump. Burr Oak would be one of the main tree species, and there’s actually some Burr Oak already present in the Boundary Waters that was established 7500 years ago in the warm spell we had at that point. And those Burr Oak trees have been hanging around for over 7000 years waiting for the climate to warm up. So for them, it would be a great thing. You know what, anytime you have a big change in the environment, it’s bad for one group of species and good for another. So what’s bad for black spruce and balsam fir and, and Jack Pine would be good for Baroque and, and red oak and basswood and red maple, for example. But yeah, I, you know, we really need to do this reduced emission scenario. And if, if you don’t like the arguments, politicians are making them. Maybe I’ll go for the argument that the Boundary Waters won’t change very much reduced emission scenario. Yeah,


Maya Swope  46:53

I think some folks maybe are wondering, too, if if they have cabins up near the Boundary Waters or other parts of northern Minnesota? Are there certain things that they should be doing now for management in terms of types of species to plant or or kind of other considerations to take at this point?


Dr. Lee Frehlich  47:10

Yeah, well, if you have a cabin, and you happen to have a maple tree, or a bass or tree or an oak tree, on your property, which you might because they are present, you know, just make sure that you don’t cut those down, because they might be useful in the future, if we do go to a much warmer climate, and you would want those species to expand. On the other hand, if you have a north facing slope, or a bog with black spruce, you want to take care of that too, because you want to keep it around as long as possible. So looking at things that are at the very southern edge of their range, and the northern edge of their range. And because it’s an edge, the whole Boundary Waters at a bigger scale as an edge habitat, you want to keep as many of those things as round as possible, so that there’s as much diversity as possible so that the forest can respond to whatever happens. If we do the reduced emission scenario, it’ll warm up a little bit by but by the end of the century, it’ll be cooling again, we might, you know, by the middle of the 2100s, for your great grandchildren might be as cool as it was in 1950. And so you would want those little remnants or rifugio, as we would call him, of the boreal species like black spruce and fir to stay around so that they could spread it but ghouls again. So we’re looking at one timeframe is here. Otherwise, you know, fire preparedness is a big deal in the Boundary Waters, because the fire season is getting longer. If we do have a drought, there’s so much more evaporation like we had this summer, because it was so hot and things dried out faster and more. That much drier than we ever thought possible in a very short time and that means more fire weather. So definitely follow Firewise principles. If you have a cabin, you know, you might want to have a balsam fir tree overhanging your roof. But in a fire that’s not a good thing. You don’t have to clear cut the forest but if the understory is not not full of Balsam first saplings, you know and there’s a project around Ely to clear some of that out. It’ll be helpful in the case of a fire so that its behavior won’t be so extreme as it approaches your cabin. You know, having a fireproof roofing material and so on and some people have sprinkler systems You know, all those things are, are things you have to pay attention to. And then you have to keep in mind that fires are actually normal. They’re the Greenwood fire like we had this summer, or is completely normal type of fire to have in the Boundary Waters, and if but the frequency of fires like that will probably go up as the climate warms. And even if it only warms a little bit, it’ll still go up. We’re gonna have drought years from time to time. And big fires are normal in that type of forest.


Maya Swope  50:38

Yeah, that makes a lot of sense. And I just want to comment, I see we saw a bunch of questions left. So we might not get to all of these. And if anyone has remaining questions, we’ll probably have time for another one or two, feel free to email me and I can pass those along and try to make sure they get answered. Um, I guess I think I kind of just wanted to end on a question tying this back to some, you know, current politics stuff. Susan is asking, what’s your assessment of the cop summit in Glasgow, is enough currently being proposed to lead to reduce emission scenarios?


Dr. Lee Frehlich  51:13

I’m not very optimistic about what happened that cop I mean, how many times before we have these these meetings? You know, we had the cop 21 in Paris, and everybody referred to it as the Paris agreement. And yet, it never actually happened. We never actually reduce the emissions that were agreed to them then. So we’ve had these different meetings over the years. And they always agreed to reduce emissions, and yet it never happened. So why should we believe them this time? So but maybe I’ll be wrong. Maybe this time will be the one where, where something actually starts to happen. But it comes from the grassroots, you know, if you, if people demand that politicians take action, that’s what makes them take action, they never look at something and say, Oh, this would be a good thing to do, I’ll just do it. They only do things because people yell at them, or complain about things basically. So the more grassroots, the more they hear from voters that it’s important, the more likely they are to actually follow through with what they agree to it some of these summits that they have. Yeah,


Maya Swope  52:35

I think that makes a lot of sense. And I think kind of re points us back to the need to get involved in local climate groups that are taking action both in Minnesota or even on a bigger level. Whether that is you know, getting more involved with the work of the friends or choosing another local group in your area that is doing good climate work, I think, you know, this is a time that we’re, you know, it’s a very serious time. And it’s clear that, you know, maybe these kind of international conventions are not the way that things will get solved most quickly. But people organizing in their own communities, is a really great way to work on that. So we are kind of nearing towards the end of the hour here. I can fit in maybe another time for one or two more questions. Um, let’s see. Um, maybe just kind of a quick question. A few people had more like specific tree related things that they wanted to know about. So someone asking are yellow birches as at risk as white birches.


Dr. Lee Frehlich  53:43

Yellow birch is actually a temperate species. So it belongs in with maple and oak and basswood. And it’s actually at the far northern edge in Boundary Waters, you know, I know of a few groves of yellow birch that are in and just outside the Boundary Waters. And because it’s at the northern edge of their range, they can be like, a foot in diameter and be 200 years old, because they’re not growing fast, because it’s, it’s not an ideal climate for them. So they would probably do better, but if it got too dry, they wouldn’t. So you know, they might end up being a swamp species in a warmer climate so they’d be able to grow throughout the Boundary Waters climatically in terms of temperature, but maybe not in terms of water, so they’re basically a warm, wet species. So they like Upper Michigan, you know, 35 or 40 inches of rain a year and three feet deep of silty soil. And winters that are not 50 below zero is good for yellow birch. So yeah, it’s they might increase in abundance for a few decades and then die. because it comes to dry, you know, because they’re limited by temperature now and they might be limited by moisture in the future if we go on the high warming scenario.


Maya Swope  55:10

Yeah. Well, that makes a lot of sense. And I hope that that answers the question for a person that asked that. Otherwise, I’ll just say thank you so much, Dr. Frehlich. For a great presentation. This is so informative. And thank you all for joining this afternoon. And for for being part of our Friends of the Boundary Waters worlds here. So thanks again. Hope everyone has a great rest of the day.


Dr. Lee Frehlich  55:34

Yeah, you’re welcome. Happy to do the presentation.


Chris Knopf  55:40

Thanks again to Dr. Frehlich. For this in depth look at climate change here in our own lifetimes here in our own backyard, in the Boundary Waters. For more information and a video of this presentation, please visit our website at Friends-BWCA.org. We’d love to connect with you. And thank you for joining us today. You are the strength of their friends. And you have made a solidity voice for protecting the Boundary Waters for the past 45 years. We look forward to having you join us again on the next Friends of the Boundary Waters podcast. Take care


On the Friends of the Boundary Waters podcast, we bring together people who share a love of the incredible BWCA wilderness in Northeastern Minnesota. The podcast will features scientists, political figures and experts in outdoor recreation and wilderness skills to help you learn new facets of the Boundary Waters Canoe Area, the most visited wilderness in the United States.

Listen on Apple Podcasts Listen on Google Podcasts Listen on Amazon Music Listen on Spotify Listen on Stitcher

Continue Listening

Old photo of Early BWCA Advocates outside Sig Olson's cabin. Text Reads,

Podcast: Guardians of the BWCA

Don't miss this podcast about the legislative and political battles from those who fought to preserve the Boundary Waters in…

Picture of Darren Bush - Podcast: Game Changing Gear

Podcast: Game Changing Gear

Find out how to choose the best gear for your BWCA trips from Rutabaga Paddlesports shop owner Darren Bush.