Reforestation: The Trees Are Planted, Now What?

This is the last episode in our reforestation pipeline series. The success of a reforestation effort largely depends on proper post-planting care and monitoring. We spoke with Dr. Camille Stevens-Rumann, who studies wildfire and post-fire recovery, to learn more about what needs to happen after a tree is planted in a reforestation effort.

Relevant links:

Marshall, L.A., Fornwalt, P.J., Stevens-Rumann, C.S., Rodman, K.C., Rhoades, C.C., Zimlinghaus, K., Chapman, T.B. and Schloegel, C.A., 2023. Seedling and growing environment measurements from a tree planting unit in the 2016 Cold Springs Fire, Colorado, USA.

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Transcript

Emile Elias: Welcome to Come Rain or Shine, podcast of the USDA Southwest Climate Hub 

Sarah LeRoy: and the DOI Southwest Climate Adaptation Science Center, or Southwest CASC, operated by the USGS. I'm Sarah LeRoy, Research Coordinator for the Southwest CASC. 

Emile Elias: And I'm Emile Elias, Director of the Southwest Climate Hub. Here we highlight stories to share the most recent advances in climate science, weather, and climate adaptation and innovative practices to support resilient landscapes and communities.

Sarah LeRoy: We believe that sharing some of the most innovative, forward thinking, and creative climate science and adaptation will strengthen our collective ability to respond to even the most challenging impacts of climate change in one of the hottest and driest regions of the world.

The contents of this podcast are for informational purposes only and should not be interpreted as endorsement for any of the products, technologies, or strategies discussed. 

Emile: This is the last episode in our Reforestation Pipeline series. The success of a reforestation effort largely depends on proper post planting care and monitoring.

This includes regular watering, protecting seedlings from pests, ensuring soil health, and mitigating competition from invasive species or weeds. Monitoring involves assessing growth rates, survival rates, and overall health of young trees. Data collected during this phase is crucial for making adjustments, such as improving site conditions, to ensure long term forest recovery and ecosystem restoration.

Today, we are speaking with Dr. Camille Stevens-Rumann, Associate Professor of Forest and Rangeland Stewardship at Colorado State University. Her research is focused on wildfire and post fire recovery. Welcome! Can you start off by talking about what happens to a forest after a high severity fire?

Why can natural regeneration of a tree species that occupied the site before be rare and what's a typical land conversion in the Southwest if conifers are not returning to a site after a fire? 

Camille Stevens-Rumann : Thanks for that question. You know, wildfires when they burn at high severity, generally that means that all of the overstory trees are killed.

So there's no longer a canopy and that has a lot of subsequent impacts on what a forest looks like. Right, if you think about the conditions under which a new tree is establishing, in the middle of a high severity patch, it's pretty hot and dry, right? It doesn't have the shade of that overstory that was there before.

So immediately post fire, we have this black landscape that everybody associates with these massive large wildfires. And through time, obviously some plants recover and regenerate. But there is a growing concern, as you mentioned, about whether or not trees can establish in these places. And some of the things that determine whether those trees can establish are things like the distance to a living tree.

We have some species that can either re sprout or drop seeds from dead trees. Something like a lodgepole pine can drop seeds or aspen, right, can re sprout from its root system. But for the most part, trees rely on some living tree nearby, and it takes a while for those seeds to get to a location, especially if we're talking about really large high severity patches like we've seen in some of our more recent wildfires.

So that's one of the really big impacts. If you don't have seeds to potentially grow the tree, it doesn't matter how great the conditions are, you're not going to have a tree. But some of the other things that can really impact it are kind of site climate, like if it's generally a hotter and drier condition to begin, a place to begin with, it's less likely to have recovery.

And so that's something we see a lot in the Southwest, where a lot of our forests are already kind of on the margin of whether or not they are a rangeland or even a desert versus a forest, right? We see that as you go up the mountain you have more and more trees, um, so you can imagine that if you have a fire near that edge It's, especially with our changing climate, that kind of tree line can potentially be moving up as it gets hotter and drier.

And then as you mentioned, there's lots of potential for competing vegetation, and one of the ones that's really common for us in the Southwest are things like Ceanothus and Gamble Oak. So we see this really big shrub response, they can re sprout from their root system, and they, you get this kind of carpet or really thick, large thicket of shrubs that can potentially be helpful, you know, if you're a seedling now underneath, enjoying that shade, but also has the potential to out compete, because they can start growing so quickly and so early.

Emile Elias: Great, so if trees are not returning naturally, then planting tree seedlings is one pathway of restoring desired forest conditions. So can you talk about the challenges and the effectiveness of replanting in the Western United States? 

Camille Stevens-Rumann : Yeah, replanting is such a huge effort, right? Um, if you've ever planted any plant, even in your yard, you know, how much effort it takes to dig it out, dig out the space to plant that tree or plant that bush or shrub or whatever it is you're planting in your yard.

And now imagine doing that across, you know, thousands, if not hundreds of thousands of acres in often really rocky soil that we have commonly. And so just physically it's a lot of effort. You have talked about all of the issues that go into and all the challenges of having a tree to grow to begin with, but there's also a lot of places where we may have thought may have been a forest before a fire that are not necessarily suited to be that same type of forest.

And so there's also that potential for us doing all of this work, planting trees in a location that's longer actually suitable or viable for it for now or in the next 20 years for there to be trees. And that's a really big unknown right now for a lot of our reforestation efforts is where are trees going to be successful in our rapidly changing climate.

So that's one of the big challenges I think that we face as we endeavor to replant so many acres is whether or not we are doing, doing it in the right places. Because there's, you know, there's the monetary and the physical labor part. There's also things like you know, we're way more likely to plant trees near a road because just simply carrying those bags of trees out, you know, miles and miles into the forest is harder.

But those also might be really good places that we want to reduce the chances of fire spreading over those roads in the future. So there's lots of kind of compounding issues, I think, that we often don't think about when we, when we have that knee jerk reaction. Let's go out and plant wonderful trees. We know we want this place to be a forest again.

And then we also know that these forests didn't establish you know, in perfect lines, right? We don't want it to look like your pecan orchard or, you know, your, your basic managed forest that's just like pines and lines is a term that we use often. Right. And so, but that, that also takes a lot of more effort and planning to think about, Oh, how do we plant trees so that we get the forest we want into the future?

If assuming some of those tree seedlings survive. 

Emile Elias: Yeah. So that's a huge amount of effort and time and money going into this huge replanting efforts that are happening all across the West. And so we want to do whatever we can to make sure those seedlings survive. And so can you talk a bit about post planting care and monitoring how it's done and why it's important?

Camille Stevens-Rumann: Yeah, so we have, there's a lot more effort being put into how to make those tree seedlings successful. So some of the efforts that are commonly done are putting them in little, like a little well, you know, a depression, essentially to capture more water as the, as that rain falls down. It's very uncommon, you know, again, across really large landscapes to be able to water them often or, you know, have people go out and visit them to, to actually add water or supplements to them on a landscape scale.

But depending on where we plant and how we plant, we can potentially have greater survival. So things like in a depression or near a shade object, right, if you think about a rock or a downed log or a stump of a tree, those seedlings tend to do better because they're, you know, kind of protected and shaded a little bit more, so they're not getting that direct full sun all the time.

That can cause mortality easier. We also know that you know, planting potentially a little bit higher in elevation or on more north aspects are some of those things that can really improve survival and likelihood of success. 

Emile Elias: Great. And I think I might've jumped ahead to this question in a way because you served as an author of an article that was published last year that focused on seedlings planted after the 2016 Cold Springs fire in Colorado.

And so can you tell us a little bit more about that research and your findings? 

Camille Stevens-Rumann: Yeah, so much like those three factors I talked about, things that increase the success or likelihood of survival of seedlings were being planted on a more north aspect. So those seedlings that were planted in really south or southwest aspects where it's especially hot and dry had lower survival.

Seedlings that were planted near a shade object, and again, it didn't really matter if it was a rock or a tree or what that shade object was, but as long as there was some kind of intermittent shade throughout the day that seedling tend to be more likely to survive. And then there was a little bit of effect of depressions and you know some of this I think is probably species dependent and you could imagine that some seedlings would really need one or more of these factors like we know something like pinion which is really common in the southwest does a lot better if it's near a shade object and we see that even with natural regeneration.

There's always that cool pinion growing up in the middle of a juniper somehow. And so that's really you know, more common maybe in some species, but having some sort of protection is good for most trees. And then some of our more recent research has also shown that if you plant you know, we don't tend to move trees around very much, especially on Forest Service property, right?

There's very strict rules about where trees can be planted in terms of finding the right seed source for a place. But if those trees are planted even just 100 meters higher than where that seed source is from, that seems to increase their survival as well. Which is really interesting to think about as we think about planting for our future climate.

Sarah LeRoy: So, based on the findings of that work and your work in general, what would you advise people working on post fire restoration in the Western U. S.? 

Camille Stevens-Rumann: Yeah, I think the first step is really identifying where we have either, you know, truly have values that it needs to be a forest again. And where we know a forest can, has the potential to be in the future, right?

There are some places that are going to burn at high severity that we really shouldn't be trying to plant because they're not likely to be a forest into the future. So I think that's the first priority. Like where do we know we really need a forest? Cause you know, obviously, especially in the Southwest, one of the big resources we get out of forests is, is water.

And so we often make these decisions on where to plant trees for kind of those ecosystem services that forests provide. So identifying where those places are that we really need forests, and then what is viable to actually live there, I think are the first two steps. That, you know, because we often, again, people see a large wildfire, there's this immediate post fire response we see from a lot of communities, like, oh, let's go volunteer and plant trees.

Sometimes we need to just take a breath and figure out where we, where we should be planting trees before we all go out and do that. And then I think on the flip side of that, there are places that are regenerating just fine. And so identifying those places, I think is really important too, because I have been in places where.

They are planting trees amongst already established seedlings, which is, you know, great to have more trees, but maybe not needed to reuse our resources that way. So finding those places. And then I think, you know, the more effort we can put into finding those right locations, like those more north aspects, and putting them near shade structures instead of just trying to get a large number of seedlings in the ground, that's going to increase the success, right?

There's a certain amount of trade off between how many trees you could just get out there on the landscape versus how many actually survive. So the more effort we can put into, you know, getting them in the right locations is going to be critical, I think. 

Sarah LeRoy: Okay, thanks Camille. So you worked as a seasonal wildland firefighter for the Forest Service for four years before pursuing a career in research in academia.

Do you think that your experience as a wildland firefighter makes you a better researcher and also informs how you conduct your research? 

Camille Stevens-Rumann: It certainly impacts how I conduct my research and what kind of questions I ask. You know, I got into this field of fire and fire ecology from that very land management side, and a really large desire to, you know, to understand these places that I had seen be transformed really quickly, right?

And I really enjoyed, part of the reason that it has inspired me why I do research now is understanding these places that I saw be changed so dramatically in such a short period of time and wanting to see you know, see the beauty and the amazingness of our ecosystems and how they are coming back after those, after those really extreme and punctuated events, such as wildfires.

So I think there's a lot of, a lot of what I do is based in having been a firefighter and seeing that transformation. I think, too, there's some, sometimes as an applied scientist, I think that things, or we all think that the things we do have some management application. And having that background, I feel like most of the time I can be more realistic about whether or not that's true.

And sometimes it is, and sometimes it isn't, I'll be honest, but you know, it does. There is a lot of times where I've read things and I'm like, I can't do anything, I, there's no way I could implement that. And I think that's helpful and just thinking about how you frame questions or what might really be important when you talk to managers about your work.

Sarah LeRoy: Okay, so following up on what you were just saying and focusing on practitioners, what are some good pathways to ensure that those people working on the ground on post fire restoration know how to best implement your research? 

Camille Stevens-Rumann: Yeah, I mean this work that we're talking about in some ways is, is extremely applied, right?

Where do you put a tree in the ground to ensure it's going to live or not, or, or survive, hopefully? And I think, you know, a lot of it comes to, in terms of implementation, one of the things I think we need to be thinking more critically about is how we reward people who do this as a job, because often this is migrant work that we pay people by the individual seedling that's planted.

And if you're getting paid that way, You don't care if it goes, you know, next to a log or, you know, in a little beautiful depression or anything like that. You want to get them as many trees in the ground as possible. So I think that part of our reward system needs to change if we really want to implement some of these actions, as well as thinking about, you know, what's the forest we want it to look like into the future, right?

Instead of planting those pines and lines, how do we make those groupy, clumpy arrangements that we often see in historical forest structures? And that again I think takes a little bit more training and involvement of the actual planting crews in a way that we often don't even at the, you know, reforestation specialist level of the Forest Service or something like that.

I think it's a lot easier to implement some of these if you have a volunteer workforce. Because you, you know, you have a whole bunch of little kids. You're like, okay, go run around and plant trees near the closest log. And you're only going to get five in, in that day or something like that. So I think there's, there's some of those kind of mechanistic ways that we do, that we do some of this implementation that's really hard to incorporate science, I think, because of that reward system. But I think the more that we can include or incorporate those people who are actually doing the planting into this knowledge and understanding, the more likely we're going to have buy in to these, to these pathways to success.

Emile Elias: Excellent, thank you. That was a great answer, and I hadn't thought about the reward system, um, but now I'm planning all sorts of different ways to do it as you speak. And, and you were talking about including people in, in the research or in understanding, so I'm curious about if you engage with communities or practitioners as you conduct your research in any way.

Camille Stevens-Rumann: Absolutely, I mean this project in specific, you know, we work directly with the Forest Service. Both the project was funded by the Rocky Mountain Research Station, so that's the Forest Service Research Branch, but also all of the plantings that we looked at were Forest Service implemented, so those Reforestation Specialists or silviculturists were really involved in that project from the, from the very start, and I think that that's, a really great way to do applied research, like all the planting projects I have going on right now, you know, stem from the questions that I'm getting from different managers on national forests.

Why should we be planting these? Where should we be planting them? Rather than me coming as a scientist and being like, you should understand this better. Because that often makes, you know, as you mentioned, more applicable science. 

Emile Elias: Thank you. And you already mentioned the, the payment system or, or the way that people are compensated for planting as, as maybe something that could change that would help make post planting activities more effective.

Are there other things that you would change within the current system that you think would help in the effectiveness of post planting? 

Camille Stevens-Rumann: I think there's a lot in the, you know, seedling prep that can potentially increase survival, right? We know things like having trees that have their mycorrhizal communities with them can have a big impact, or having trees be a little bit drought stressed in that nursery environment can help in, you know, get them used to those drought conditions that they might experience in the field.

So those are some of the other things that come to mind immediately that we often don't do a great job of assessing once they're out in the forest because how do you keep track of which trees were droughted or not, or had this augmentation or that added to it. So it can get really complicated to study, but we generally know that those practices can lead to greater survival.

Once they're out in the field, you know, there's, there are things that I've struggled with how, how that could get implemented. Like we know if you plant in a year that happens to be a better summer monsoon season, for example, you might have a greater survival, but I can't predict that super well when I plant those trees in April.

And so those are the kind of those some of those like unfortunate things where you learn as a scientist that after the facts that are good to know but I'm not sure how you implement them other than being like well it's an El Niño or La Niña year so maybe we'll have a a better or greater or less chance of having good rainfall in the summer but there is that there is a strong correlation obviously with rainfall.

Sarah LeRoy: So you have a project funded by the Southwest Climate Adaptation Science Center. And I was wondering if you could just tell us a little bit about that project and what the research is and who's involved in it. 

Camille Stevens-Rumann: So that project is on the, you know, pre fire more than post fire or during fire events, I should say.

It's looking at basically how and why our wildfires are becoming more so extreme and what can predict it or potentially influence whether a wildfire becomes as large and as detrimental as it is. And so that project involves Jonathan Koop at Western Colorado University, and then we have a couple Forest Service partners, Sean Parks, who's at the Aldo Leopold Research Institute.

And a couple of other additional collaborators at Northern Arizona University as well. And it's, it's an interesting project because often a lot of my work as we've been talking about focuses on that post fire. What do we do once that fire has burned? And this is an interesting way to look at like, well, what are the conditions that lead up to that post fire landscape?

We know that climate change is changing multiple facets of wildfires, I think. And I often think about it as both what climate change is changing, how fires are burning in themselves, and then how, how climate is impacting that post fire landscape and the potential for recovery. And so this project kind of spans that first part.

How is climate change impacting how these wildfires burn? And what does it mean to have a really large wildfire? And is there anything that can stop that, right? When you have the extreme conditions that we've seen sometimes, like Here in Colorado, we had, you know, 6, 000 acres an hour burn overnight over the continental divide.

I'm not really sure what kind of thing could have stopped that. Certainly, all human augmentations, like firefighting actions, didn't change that fire behavior when that was happening, but we have been looking into things like if Aspen has, if you have a huge Aspen stand, is that impacting how that fire burns?

And there is some interesting findings that it is, that there, if you have a different, if you have that shift in forest type, you're more likely to see kind of a drop or change in fire behavior, because we know aspen tend to be more, have more moisture in that system, there's less fuel, that forest looks dramatically different, and that's something that we could kind of preempt a lot of our forest for having more of, potentially.

Sarah LeRoy: Okay, thanks Camille. So this next question is related to hope and is something we ask all of our experts on this podcast. And so I'd like to ask you, what gives you hope? 

Camille Stevens-Rumann: I don't think I could study post fire landscapes if I didn't have some hope. And I think, honestly, they give me hope because we often, many people perceive post fire landscapes, especially right after a fire, as they're just so bleak.

You know, they're lost in some way. We use these terms of loss and devastation and dramatic change. And one of the things I really love about being a fire ecologist is going and seeing all the amazing and beautiful ecosystems that come back in these places. And even if it doesn't look like what it was before the fire and won't ever look like that again in my lifetime.

There is a lot of hope, I think, in seeing that beautiful fire weed coming back, or I get so excited every time I see a baby tree. You know, I think people get very annoyed at me at this point that know me well. I'm like, Oh, there's another one. So seeing those kinds of signs of recovery and regrowth is always really hope inspiring because you know, our ecosystems are amazingly responsive to these disturbances and fire is a natural process in these places and has been a part of that. Maybe not in the same way that fire is interacting with these landscapes today, but they certainly have been a critical part of these ecosystems for millennia.

And so I find a lot of joy and beauty in in how those places are recovering and responding to these very natural processes. 

Sarah LeRoy: So last question, what's one thing that you want people to remember from this conversation? 

Camille Stevens-Rumann: I guess in, in this vein of talking about reforestation, I think one thing that I think it's, is critical to remember is that we have, you know, a lot of places that don't need trees or shouldn't have trees replanted on them. And I think, you know, we should and could replant, you know, many other places. And it's a lot of the, this work is really about finding those critical locations that this work should be done, because we know we can't reforest every acre that becomes unforested because of a wildfire.

And I think that our efforts should be much more strategic than we often do now. 

Sarah LeRoy: So it's been a great conversation and we appreciate it. So thank you. 

Camille Stevens-Rumann: Thanks for having me.

Emile Elias: Thanks for listening to Come Rain or Shine, USDA Southwest Climate Hub 

Sarah LeRoy: and the USGS Southwest CASC. If you liked this podcast, don't forget to rate or review it and subscribe for more great episodes. A special thanks to our production crew, Skye Aney and Reanna Burnett. If you want more information, have any questions for the speakers, or would like to offer feedback, please reach out to us via our website.