Climate in Minnesota - how it helps and challenges pest management
Welcome and good morning to everyone. This is the first episode of 2021 for the University of Minnesota IPM podcast, Field Crops. Today, we have Heidi Roop with us. She is the assistant professor and extension specialist climate science for the University of Minnesota, a recent hire as well. So welcome, Heidi.
Heidi Roop:Thank you. Good morning. It's great to be here, virtually that is.
Anthony Hanson:Lately, we've been doing all of our recordings over Zoom, so that's been a little of a transition for us in 2020 into 2021. But at least it's working out okay for us so far. So, Heidi, you wanna introduce yourself a little bit just in terms of where you've been before, what you're planning to, and what interests you about Minnesota, especially in terms of climate?
Heidi Roop:Yeah. Great. It's wonderful to be here. It's wonderful to be back in the Midwest. I I grew up in Wisconsin.
Heidi Roop:So still a Midwesterner, but not a Minnesotan. I understand that will take a long time to be able to claim that fame, but it it's really wonderful to be here and to be learning about Minnesota's weather and climate. And in my role, I'm really charged with thinking about what the future holds for Minnesota in regards to our climate system and importantly, how we prepare for those changes. This audience that's listening, you are the masters of preparation, and the word we use in my field is adaptation, preparing for the stressors and the risks that our weather and climate system pose for our day to day decisions and for our livelihoods. I've been here since the July.
Heidi Roop:It's actually, I guess, marks six months today since I started in this new role. And all of course, all of this has been virtual. So the thing that saddens me the most about the process at the moment is that I haven't had the opportunity to get out on the landscape, importantly, meet people and build relationships. And so I guess what I'm looking forward to is, you know, I can read all my books and analyze all the data, but nothing compares to actually talking with people and hearing sort of what are the challenges that they're grappling with and how can we work together to bring information and resources to help tackle the challenges that we know are emerging across the landscape as as our climate changes. So I look forward to hopefully working with many of your listeners and, of course, working with you in extension.
Heidi Roop:So it's it's really wonderful to be here and can't wait till I can really feel like I'm here in Minnesota.
Anthony Hanson:I'm sure you've been asked this most times when people first introduced you. The person formerly in your position was Mark Sealy, and people in Minnesota know that name pretty well. So how has the transition been for you in terms of you know, he had pretty broad breadth. He was here for years. What direction are you looking at either in terms of things that he did do before, but more importantly, what direction are you wanting to take yourself possibly in different areas?
Heidi Roop:Yeah. Thank you for that question. You know, I when I first started my position, I did ask Mark Sealy how big his shoes were because everyone keeps saying they're such big shoes to fill, and I think they're size twelve. So I don't stand a chance. But but, you know, that's really not the goal here and and the position that as it was envisioned by extension and by the Department of Soil and Water and Climate, where I hold a faculty appointment, where Mark also held a faculty appointment, was really about how to build on the the really robust foundation of knowledge and relationships that Mark created in Minnesota.
Heidi Roop:You know, I get the challenge and the opportunity to build on that foundation and hopefully shepherd those relationships moving forward. And and kind of taking Mark's emphasis, he served as the extension climatologist. So he always has the expertise and still does with his WeatherTalk blog and and everything else. And he, of course, is is helping me learn this new role and and identify sort of what's important as we move forward in shaping the program that I'm I'm working on building. But really taking this foundation that Mark created and this interest and knowledge of weather and how it's connected to climate and our future and this need for managing the risks that a a climate changed future will bring.
Heidi Roop:And so my position as the extension specialist focusing on climate science and climate adaptation is really about sort of building that bridge between near term decision making, which is really connected to sort of the weather, the things we experience day to day, week to week, season to season, and how we start to incorporate more planning and thinking and investments that bring in the knowledge that we have from the climate science community that shows that we are going to be experiencing and already are in many cases, experiencing change on our landscape that's really requiring us to prepare. And so my position and the program I'm building is really aimed at kind of taking that next step and thinking about not only what does it look like to understand what the future sort of future climate might look like, what are the extremes we meet we might experience, but critically, how do we prepare for those changes? And to maybe be a bit more specific, it's really about understanding not just what sort of scientific knowledge and data do we need, but, critically, how do we actually deliver that information, engage with folks like those that are tuning into this podcast to understand first what what information and data are needed, and then critically, how can we increase the use and application of that information, whether that's working with the state to remove or create policies that reduce roadblocks to to these changes, to creating incentive structures that make it easier, say, for farmers to afford the equipment they need to maybe manage planting cover crops or supporting the development of of more robust markets and supply chain.
Heidi Roop:So it's really a whole systems approach, and and I guess Mark was sort of the foundation builder, and I get to sort of think about now how do we build on that foundation and create something that can help all Minnesotans march forward in a way that maintains and and supports livelihoods and our working lands well into the future, even as we know the sort of extremes that we are experiencing continue to increase, like changing precipitation patterns and warmer winters, which I think we'll talk about here in a minute.
Anthony Hanson:So thank you, Heidi. This has actually been an episode I've been looking forward to for a while. Part of the work that I've done in the past has dealt with basically pest overwintering, and I've been especially interested in weather and climate data because of that. So this is gonna be a thing I think a fun episode to be able to kind of dovetail these two areas together a little bit. And I should reintroduce myself.
Anthony Hanson:I'm doctor Anthony Hansen, an IPM Extension Educator with University of Minnesota. In terms of pest overwintering, there are some concepts, think about climate data, you're looking at where, say, an insect is overwintering. They could be actually experiencing air temperatures above a snow line. They could be in the snow or down in the soil as well. So each of these are kind of different temperature gradients and also different, environments for things like moisture, humidity, and all those components can affect whether an insect survives through the winter.
Anthony Hanson:And that can be great if we have a cold winter and we have some pests that actually get reduced in numbers or if the winter keeps out some invasive pests from more southern areas that can't tolerate our cold winters here. So I was wondering if you wanted to talk a little bit about what kind of trends do we see in some of these, let's say, for air temperature in Minnesota or what do we expect to see, you know, within the last ten, thirty years or so. As a good example is maybe soybean aphid where they overwinter eggs on buckthorn. They're above the snow line. They're basically experiencing air temperature.
Anthony Hanson:And if the minimum daily temperature, it's about negative 30 Fahrenheit, that's about the point you start to see some of those eggs dying off. There are other factors that play into that, but how often are we gonna see negative 30 degrees Fahrenheit, does it seem like?
Heidi Roop:Yeah. So, you know, I I don't have a crystal ball, so I can't tell you exactly how often or or when. But what I can tell you is that our observed changes, so these are these are changes, these are data points that we gather from instrumentations, weather stations distributed across the state and the region. We can see that over the annual cycle, temperatures are increasing. This is occurring especially at night and is amplified during the winter.
Heidi Roop:And so this is, often referred to as sort of cold weather warming, and so this is where those cold extremes, so those those negative thirty days that you're talking about are becoming less common and sort of less severe. So we essentially are seeing a rapid change in our thirty year average of winter lows. Just to toss out a bit of data here, I know that's hard over this platform, but, the state climatologist office aggregates a lot of these data and and you can go on and actually interact with, information that we're discussing today to see what it really means for for your region. But if we look at the the late nineteen fifties through the late nineteen eighties, for sort of the northern band in Minnesota, the average winter low temperature was around minus 10 to minus five degrees Fahrenheit. Between the late nineteen eighties and 2018, that temperature band, sort of those average winter low temperature shifted to minus five to zero degrees.
Heidi Roop:So you can see and we we actually see a very strong north to south gradient in this warming, meaning the northern parts of Minnesota are warming more rapidly. But on the whole, as a state, our average winter low temperatures are going up. So those low lows, are going to become less frequent and sort of less common as we march into the future. And, again, those are are observed changes. And when we look at projected changes, so what might the future hold in mid century and beyond, we see those patterns will stand, and we will be experiencing not only warmer winters, but we expect to see more days with, greater than sort of four inches of snowfall.
Heidi Roop:So that heavy snowpack will also be increasing. So it's really about, in winters, this combination of more snow and less cold. And because we are warming our winters, we also are expecting more thaws. So more of that kind of freeze thaw cycle, which as, you know, you just described with your expertise likely has real implications for how we're gonna be managing safer pests today and into the future.
Anthony Hanson:Yeah. So that is a concern like I mentioned before, especially for some of these invasive species that are coming in. Recent one is brown armory stick bug. That one actually overwinters indoors, so we we aren't as confident in winter being able to hold that one back regardless of the temperature. But then there are other ones where, you know, they may be able to survive down in Florida, but they might have just enough cold tolerance.
Anthony Hanson:They might be able to sneak a little bit further north, a little bit more, and we don't know how far they'll get if they'll get Minnesota or not. They might be stuck more around Missouri or something like that. But, yeah, it's kind of an unknown right now. We can go and measure the base of the thermal tolerance, how cold can they withstand either just an acute single night or roughly over winter. That's literally just throwing insects into a freezer and seeing how long they can survive that.
Anthony Hanson:So we do have some ways to predict and model if we know the temperature, how far they might be able to make it. But, yeah, right now it's kind of an unknown for some of those as far as how well those models accurately predict where an insect might be able to show up too. So it's definitely something on our radar in terms of keeping an eye out for new pests or even ones that have been hanging around a little bit, but we're always tamped down by the winter and never really reached a pest status. And then also they can kind of flip a switch. They're becoming a major pest.
Anthony Hanson:And I know Western Union cutworm is one of those where it has spread across The United States a little further north and east compared to what we've seen before. And part of that might be overwintering where it overwinters in the soil and it still looks like Minnesota, it gets too cold for it to be able to survive very well. But if you get down to Iowa, especially Nebraska area, they generally don't reach temperatures that should be able to kill them off. Even in Minnesota, we might be at the borderline.
Heidi Roop:Right. So I guess one of the things that really interests me and that I love if you educate me and and potentially some of your listeners, I I wish this were interactive so we could get some some phone calls here. But, you know, in thinking about that, you know, what does it look like pests sort of over the annual cycle. But in terms of the this challenge of the winter warming and and some of these unknowns, right, like, pests might we have that goes in tandem with the question of what crops are gonna be most productive in Minnesota in the future. We see the Corn Belt migrating north.
Heidi Roop:Right? We have these questions about the crops and the pests. And I guess, do you see or have you had any discussions about what some sort of solutions might be or what what could help us manage for both of some of these knowns and these unknowns?
Anthony Hanson:Yeah. So it depends, like you said, especially on the crop and then the specific pests which complicates it to be able to cover in a quick manner. But let's take an example of corn rootworm that overwinters in the soil, so we may not be able to really control or manage things differently aside from realizing that further north might be planting more corn, corn rootworm might expand its range up there. There are other ones that might be more affected by temperature without that kind of buffering effect of the soil. If they're up in the leaf litter, if maybe let's say, here we don't get much snow and you can get e leaf beetle and some of these other ones that kind of that leaf litter area.
Anthony Hanson:Now there is some work going on into predicting based on temperature when they'll show up in the spring, but also maybe how severe they'll be. So, basically, it comes down to prediction and trying to see if we can gauge what a year will look like. And some of that comes into basically the spring and summer modeling we do with phenology and for growers out there, this is basically the same thing as your corn growing degree days. We use degree days for predicting when insects are emerging, when they reach certain life stages, and when you should be out there scouting or making a management decision. And those prediction models basically use a temperature regardless of what conditions are, so if it's a cool year or a warm year, those help predict whether the insects are going be able to emerge earlier or later as well.
Anthony Hanson:So we have some flexible tools, but sometimes they may not work as well either, so we need to keep retesting them in these different areas. If you have a new region, let's say has a different soil type that has been tested before, it might actually be that temperatures are a little warmer that we don't capture, say using air temperature weather stations and that insect might actually show up earlier than you'd expect. So we wanna be out there kind of revalidating some of these models and that's where a lot of discussion has been lately on what we could do there. But in terms of management after prediction, it's a little more just being ready to adopt the tactics we might be using further south in the state and teaching people up north, oh, here's what we do down south. And I'm talking in Minnesota, but it could also be regionally or across the country too.
Anthony Hanson:So it's just learning what other people are doing in areas that have had problems with that pest is by mostly what we focus on.
Heidi Roop:Do you think that infrastructure is in place to facilitate that sort of knowledge sharing and, you know, exchange? I guess I ask in part because I'm I'm curious about how to how to do this, the work that I'm focused on and thinking about preparation for the future, those networks for communication, for knowledge sharing. Right? You're one person. I'm one person.
Heidi Roop:We have listeners who are across the landscape. People could be collecting those data and and helping validate those models. And then, of course, we have people for their self and and other climate settings that have a lot of lived and applied experience. So I guess I sort of know in my discipline where some of the strengths or weaknesses are in our our networks for sharing that knowledge. But do you have any insights on whether those networks are in place or is that something that you all are working on that could support this community?
Anthony Hanson:Yeah. So that is definitely extension's role is getting this information out there to people. But in terms of infrastructure when it comes to pest management and weather, that is something that's definitely been in discussions for a while and how can we improve that. Some of that is trying to develop more, basically, weather station networks and monitoring there. And something I'm working on too, I mentioned before, is with these three day models, can we get something out there that gives alerts to growers?
Anthony Hanson:And that's definitely a work in progress there. But, yeah, this is definitely an area where there's a wide open area that gonna be able to push new ideas and try to develop some infrastructure. So that's of the things I'm definitely looking at in my role. An IPM educator, I kinda cover the full gamut of all these different topics that can affect pest management. But like I mentioned before, weather and climate is kinda one of my main interests.
Anthony Hanson:So that's one thing we're looking forward to being able to develop new tools. Yeah. In terms of what infrastructure we might have with other, you know, states, we have collaborations with other folks in extension. We get down to Iowa, Nebraska, other areas. We definitely talk to them and say, hey.
Anthony Hanson:What's going on in your state? We'll learn about it, and that's possible that it shows up in five to ten years. And we've heard about it. We know a little bit about, how that pest is managed. So we have that wherewithal to be able to put information out there right away through extension is to keep a lookout for this insect, whether it's a disease or weed as well, and get more information out there.
Heidi Roop:Yeah. It's hard, isn't it? Yeah. There's so much going on and, you know, I think some of it, and I'm I'm learning this in my role that, you know, a lot of it's about thinking about talking to people that you wouldn't otherwise necessarily talk to or, in my case, you know, being new to a lot of this work and learning a lot. So, you know, one of the things that has recently surfaced that was a really fun learning opportunity and we're gonna hopefully work on some videos, but to help explore some of these topics, but was actually looking at, with the folks in horticulture and extension, had a lot of questions around sort of growing season and pest management.
Heidi Roop:I appreciate their, different pests, but I think some of the management challenges are similar. In that in that context, it was thinking about, you know, we've we've observed that the growing season regionally in the Midwest has lengthened by about fifteen days since 1950. Right? And that has implications for so many decisions. But what happens as a consequence of that is not sort of just around the timing of when you plant, but there's some examples.
Heidi Roop:I've doing this research and looking at Michigan and out in New York. This is particularly around apples. Actually, seeing that there are now additional cycles of pests. So where in past seasons, a farmer would be managing for sort of two rounds or cycles of of a pest, they're now exposed to three. And that, of course, has costs associated with it and increased risk because now there's sort of different times in which pests are present throughout the the growing season and and into harvest.
Heidi Roop:So I think, you know, it's when we do this work and think about how do we understand the problems and work towards solutions, I think these opportunities for conversation and knowledge sharing are are are critically important because, like, as as you said, you know, in the South, climate is it's a different climate sort of fundamentally, and it is also changing but in different ways and and what are the lessons that we can take and so that we don't make the same mistakes or or hit the ground running in our own risk management for for these climate impacts.
Anthony Hanson:That's actually a good example that you had me thinking about soybean aphid again, which is one of our main pests of soybean in Minnesota. And when we use IPM, we're using our basic decision thresholds of going out, see how many aphids are and using that to inform whether we should be using insecticides or not. And most of the time if we're using these thresholds, we can hold off needing to use any insecticide till maybe the very end of the year. In Minnesota generally, we only need to apply once. And even though those populations might rebound over time, by the time that happens, usually we're about to September or very August.
Anthony Hanson:And at that point, they're getting their cues that it's fall, it's time to go back to the buckthorn. If we had an extended growing season, then we might be more concerned about having to apply insecticide more than once. So that's kind of one example we think about climate a little bit with extending the growing season, but that is a concern compared to other states where they definitely do have a longer growing season.
Heidi Roop:Our growing season is lengthening here in Minnesota, and there's different combination of stressors that are happening early season and late season. And, actually, I was just speaking with a with a farmer last night who was talking about, and this is a term we use a lot in this work, is sort of whiplash. Right? You may have a longer growing season, but it may be wet because we're experiencing more extreme precipitation events and more of our these warmer winters result in more of what formerly would have been snow is now falling as as liquid precip, so falling as rain. We get wet fields.
Heidi Roop:We get all these problems, but then, you know, you may be oversaturated with water. And then within a couple of months or mid season, you're headed towards or or living in in drought conditions. And so it's that maybe this is stepping a bit beyond pests, but it's sort of how do we how you manage and cope with this whiplash where you might be thinking, oh, man. I've got this really wet spring. This might carry through, but by the end of the season, you're more exposed to drought.
Heidi Roop:These changes are, I think, really meaningful as we as we think about it. I should be clear that the observed data for drought show that statistically insignificant, the the changes there, but we are anticipating possible increases in in drought by mid century. Again, this is an active area of of research. But, again, it's a sort of oscillation between wet and dry condition and and sort of getting tugged and pulled within one growing season in multiple directions, and that can be, you know, just almost impossible to manage. In the absence of structures that help allow you to to, say, have a some crop loss and you've got sufficient insurance or there are other sort of incentives and protections in place.
Heidi Roop:And I I'm I'm hearing loud and clear on the landscape that those things are needed, and this conversation makes me wonder if they're sort of more needed in that space of thinking about pest management, especially for the pests that we don't yet know might be in our own backyard before too long.
Anthony Hanson:Yeah. So that whiplash is a good example because that variation kind of the sudden changes in whether it's temperature, precipitation and whatnot, that does make it harder to predict what's going on. Spring is usually the hardest season to figure out what's going to happen, whether it's what the temperature is actually gonna be or what all of our critters are out there doing. And now I'm talking about the insects a lot, but we also got other main pests where it's diseases and weeds. And weeds are one example where you might have some plants that are surviving through the winter, then you also have the seed bed as well.
Anthony Hanson:And they're kinda giving that a start with the earlier springs even those kind of fits and starts that gets some out of that kind of winter activation a little bit back into being ready to grow. And we have basically a long growing season for the weeds as well and likewise for diseases because they're all basically temperature and moisture based to some degree or another. So that's part of our challenges there. And I was wondering too, especially with diseases, a lot of those do deal with humidity a lot more. So what kind of trends do you think we're seeing with moisture in that sense, especially when we get into spring and into summer?
Anthony Hanson:You mentioned drought a bit, but what's our moisture in the air looking like now?
Heidi Roop:Yeah. So that's kind of a multi a multi part question when we when we look at what we're able to sort of project into the future. I can say that our our observations of, say, things like extreme heat in the summer, though those instrumental records aren't showing any statistically significant increase. However, by mid century, we actually expect to see several more days per summer where temperatures exceed that 95 degree Fahrenheit threshold for sort of, quote, unquote, extreme heat. So, you know, sort of overall, we're we're warming the climate system, and so, know, we will be marching towards sort of hotter summers in those with more extreme temperatures.
Heidi Roop:But that importantly is paired with changing precipitation patterns. So we are seeing increases in primarily the sort of heavy intense precipitation events. And so we're seeing, you know, around a a sort of an average station across Minnesota. And, again, these data come from the state the state climate office at DNR. But sort of a typical station is around 20 to 40% increase in in one inch precipitation events relative to the nineteen hundreds.
Heidi Roop:So that's that bumps up to around a 60 to 90% increase in in precipitation events around three inches, and that again is relative to the early nineteen hundreds. So when we look at these long term datasets we have for across the state, we're seeing more of these extreme precipitation events occur in the context of of warmer conditions. So those are kind of tied into one another. Warmer atmosphere atmosphere holds more water. But, you know, that's not specifically humidity, but I I think we can agree on is that when we pair the sort of whiplash with the sort of overlying shift in the baseline in a warmer climate and one where we're experiencing more of these wet extremes, we're gonna be kind of changing the the context in which which we operate and with in which plants grow and and pest thrive.
Heidi Roop:And so, again, I'm not the expert in in how to how to manage for those. And I think, again, it's gonna take a lot of creativity and thinking about those things. And and as I said earlier, you know, setting our sights on other geographies where they are already living in these conditions as part of their baseline climate, and what is it that we can learn from their best management practices that we could start to be implementing now in in preparation for these, or at least building out the tools and resources so that we can better manage that whiplash. So that you don't leave that, you know, sort of car accident of a summer or growing season completely defeated a need of physical therapy. Right?
Heidi Roop:This if we're prepared, you know, we can maybe manage these these sort of changing conditions more easily. Right? And I think the other thing when we have these conversations around weather versus climate, it's really important to note that even as we look towards future kind of climate extremes, that natural variability will always be part of our system. So there will be years where it's dry. There will be years where it's wet.
Heidi Roop:It will be hot. It will be cool. It will be these sort of normal conditions. We still will be experiencing the variability that's defined by our weather, but the sort of baseline that we're operating in is shifting as the planet warms. So one of the ways that I think I remember the distinction, and I think is when these things emerge can can maybe provide at least a moment to laugh.
Heidi Roop:So climate is basically our personality. It's the personality of our region. It's the personality of the planet. Right? There are climate regions, and those sort of define the general long term characteristics of a place.
Heidi Roop:And weather is sort of your mood on a given day. Right? It's whether you wake up on the wrong side of the bed or you don't have enough coffee before you walk out the door. And so, you know, your your mood on a given day isn't necessarily the only indicator of isn't the indicator of your your personality. But what we're doing essentially is we're changing the personality of of mother earth to being one that's more prone to being ornery and less predictable and and having, you know, more of these mood swings, if you will.
Heidi Roop:So I sort of like to think about it in that way that, you know, we're still gonna experience that day to day change in mood, but we're we're gonna need to figure out how to manage that shift in in her personality as well.
Anthony Hanson:Well, thank you, Heidi. We think we're just about ready to wrap up here. But I was wondering, do you have any questions you're looking to answer that you would like to hear from farmers or get their sentiment on things that they want addressed?
Heidi Roop:Yeah. Of course. You know, I think huge part of our role in extension, I I most certainly feel this in my role in particular, is is really about listening and trying to understand, you know, what are the impacts and the changes that you're grappling with and what would make solutions feasible. How can we both test and deploy and work towards solutions that that work, right, that don't put up more roadblocks, that don't put up impediments to your work, that help reduce your exposure to to risks, the range of risks that you manage every day to do what you do. And so, you know, part of that in in full honesty is learning about your work and those challenges and those roadblocks.
Heidi Roop:And I'd love opportunities to get in dialogue and think about how how we can work together to remove those roadblocks. And and again, sort of looping back to the to the center of this conversation, which is really about, you know, how do we look to other regions and learn? How do we look to our peers to learn? And I think so much of it is about being willing to be in conversation with one another and really try to work towards, you know, a a common language and some some common goals that that really help us better manage the the risks that we are already grappling with and and facing, but, again, the amplification of those risks as as our climate system changes. So I guess the thing for me is I'd I'm I'm looking to be a partner and a willing learner.
Heidi Roop:And, of course, none of this work is one and done, and so I really see this as, you know, the folks who who want to sort of develop relationships and partnerships. I I would love the opportunity to connect with you and learn from you and think about how it can help make your jobs and your days easier.
Anthony Hanson:Alright. Well, thank you. This episode was with doctor Heidi Roop, assistant professor and extension specialist in climate science, And we'll have more episodes coming up this winter and spring before the growing season starts. So hopefully, we'll get some more info out to folks here before they really start getting out in the tractor and doing other work here. Thank you, Heidi.
Heidi Roop:Thank you.
