Pennsylvania Legacies #192: Moving the Needle on Conifers

Coniferous trees once figured prominently in the makeup of Penn’s Woods, but their populations never fully recovered from the deforestation of the nineteenth century. Now Pennsylvania’s conifers face a new threat: invasive competitors and pests, warmer and wetter weather, and other disruptions linked to climate change.

We explore an evergreen topic with Joe Stavish of Tree Pittsburgh in advance of the group’s upcoming Conifer Symposium on June 14.

Southwestern Pennsylvania’s struggling conifer population is the focus of an upcoming discussion hosted by TreePittsburgh.

The Allegheny County Conifer Symposium will be held June 14th in Pittsburgh’s Lawrenceville neighborhood, bringing together experts from across the region. The event comes as a host of climate-related issues, from shifting growing seasons to worsening pest problems, threatens coniferous species in the region. Among them is the official state tree of Pennsylvania, the Eastern Hemlock, which is increasingly vulnerable to the invasive hemlock woolly adelgid amid warmer winters.

“We don’t have a good percentage of conifers in the region, and, and a lot of them aren’t doing as well as we would like to see,” said TreePittsburgh’s Director of Education, Joe Stavish, who’s behind the symposium.

Conifers are an ancient group of needle-leafed, cone-producing trees. They provide numerous benefits, from cleaning the air and water to sheltering wildlife and homes from wind. They’re especially important in the winter, when deciduous trees lie dormant.

“When we think of trees as a whole, no matter what group we’re talking about, there are many environmental services and benefits that they provide to us,” Stavish said.

TreePittsburgh is a nonprofit that aims to restore and protect the urban forest through tree planting and care, education, advocacy, and land conservation. The goal of the Conifer Symposium is to better understand the problems plaguing conifers and begin identifying possible solutions. It will bring together researchers from places like tree institutions, universities, state departments, and forestry divisions who will work to devise a better approach to tree planting that will foster resilience and biodiversity. In light of climate change, these experts seek to identify which species are better positioned to do well in the coming decades.

While this particular event isn’t open to the public, TreePittsburgh wants to get more people to understand and value the importance of trees — particularly so they make educated decisions about how they’re choosing, planting, sourcing, and caring for them. The organization is even looking to Christmas tree farmers for help with its conservation efforts.

“We’re definitely looking at a lot of our big growers in the region in the future to communicate, go and tour their nurseries, their farms, see how they’re growing conifers and see how some of that information may benefit us,” Stavish said. “Or on the opposite end, how we can start a lot of these diverse conifers and then send them out to these larger farms.”

PEC talked with Stavish to find out more about TreePittsburgh and its upcoming event.


Josh Raulerson (00:01)

It’s Friday, May 26, 2023. I’m Josh Raulerson, and from the Pennsylvania Environmental Council, this is Pennsylvania Legacies. 

Over the course of the 19th century, Pennsylvania lost about two-thirds of its woodlands to logging. By the end of the twentieth, much of Penn’s Woods had been restored. But its composition had changed. Gone were the vast old-growth forests dominated by towering white pines and hemlocks. In their place, today you’ll find mostly mixed-oak and northern-hardwood forest.

The Eastern Hemlock is still the official state tree of Pennsylvania — and the unofficial mascot of PEC, as featured in our logo — but hemlocks themselves are much less prevalent than they were, outside of a handful of areas. And those populations are increasingly threatened by the invasive hemlock woolly adelgid, which is gaining a foothold in Pennsylvania as climate change brings warmer winters.

The plight of the Eastern Hemlock is one, relatively well-publicized, example of how coniferous tree species are struggling in the Commonwealth. But it’s just one example.

Rising temperatures and changing growing seasons, shifting habitat ranges, migrating pests and invasives, and a host of other climate-related conditions are casting a shadow on the future of conifers — especially in places, like southwestern Pennsylvania, that were never that conifer-friendly to begin with.

That’s why the group TreePittsburgh is bringing together foresters, land managers, arborists, climatologists, ecologists, and advocates next month for the region’s first Conifer Symposium. The goal is to better understand why southwestern PA’s conifers are declining and to begin identifying possible solutions.

Joe Stavish is TreePittsburgh’s Director of Education, and our guest on this episode. Joe, welcome to Pennsylvania Legacies. 

Joe Stavish (1:51)

Thank you so much for having me here.

Josh Raulerson (1:53)

Let’s go back to like, I don’t know, maybe middle school biology, and just a little refresher on how conifers are different from other kinds of trees, and why, why that matters in this context. Does that make them more susceptible to environmental threats?

Joe Stavish (2:07)

It’s great question. Conifers are a more ancient group of trees, and when we look at difference between conifers and other trees, it is like a middle school science lesson. Conifers produce cones. They do not flower. They produce naked seeds. Conifer means naked seeds. And when we think of the group of trees they’re in, they’re in the gymnosperms — no flowers. Angiosperms are gonna be everything else. We’re familiar with oaks, maples, hickories. They produce flowers, they produce some sort of seed nut berry or coating that covers their seed. Conifers typically have needles and produce cones. 

Josh Raulerson (2:43)

Okay, so when we think about the role that conifers play in Pennsylvania’s forest, so, but like about, you know, how much of, of the tree cover do they comprise? What, where do they fit?

Joe Stavish (2:52)

It really depends on what part of the state you travel to. Here in our Pittsburgh region, we do not have a large population of conifers. Um, that’s clearly seen in the winter months when all of our deciduous trees are empty and bare. You can see where the conifers are or where they’re not. As you move to more mountainous parts of this state, central, northern parts of Pennsylvania, the conifer trees are more common in those areas. So they’re not evenly dispersed, especially in built urban areas. We don’t have, uh, good percentage of conifers in the region, and, and a lot of them aren’t doing as well as we would like to see.

Josh Raulerson (3:28)

And why is that? Like what’s distinctive about this part of the state that makes it maybe less, uh, hospitable to conifers? 

Joe Stavish (3:34)

For a lot of the conifers species, we may be at the southern end of their range. So as you leave Pennsylvania, go north, even up into Canada, that’s where we typically think of trees with needles, conifers. Now there are some species that we are at the northern range, uh, where we have them here, but for the most part, Pennsylvania’s kind of the southern range for a lot of those. More of a colder, uh, type of tree that’s more adapted for snow regions, like long term. 

Josh Raulerson (4:00)

And I mean, I guess I’m assuming we’re looking at a future not too far ahead where those ranges are, are gonna be moving or I guess they’re probably already on the move. 

Joe Stavish (4:07)

Those are the predictions. There’s lots of shifts that will be happening with all of our different tree species. So in the Pittsburgh region, we’re trying to experiment with more southern species of conifer and planting them here. Uh, hopefully they’ll do well over the next 10, 20, 30 years. And a lot of our native species of conifers that we have been seeing planted historically aren’t doing very well. 

Josh Raulerson (4:28)

And why is that? 

Joe Stavish (4:30)

Well, it’s a combination of issues. So a lot of it does go right back to climate change. So we’re having, uh, you know, warmer, wetter summers, we’re having milder winters. And that stresses out some of the trees, but it also brings in a lot of pest and disease issues. A lot of that being fungal based, so when we have wet warm springs in summers and mild winters, we see fungus spread quickly, uh, through a lot of our tree species. 

Josh Raulerson (4:56)

And are they also having to compete with invasives and that kind of thing? 

Joe Stavish (4:59)

It’s a little bit of everything. So when we look at, you know, where trees are, um, conifers are not well adapted for growing in shade of other trees. So hemlock can be in the exception. So conifers need to be in the outside, open areas. And for a lot of people, they’re, they’re forgotten about when we’re doing a new planting or designing a space, uh, or we’re only choosing the same types of trees over and over again. So the diversity is, is sort of low, uh, for a conifers specifically. But yeah, a lot of it’s just pest and disease issues and competition from invasive development, um, and everything in the region. 

Josh Raulerson (5:32)

And so when we talk about like, why conifers matter and, preserving conifers matter, obviously you would like to say trees have value just intrinsically in their own right, and we should preserve them for their own sake. Is there also another level of, you know, like ecosystem services or, or economic value that can be ascribed to, you know, having a healthy population of conifers? Does that figure here? 

Joe Stavish (5:53)

Yeah, definitely. When we think of trees as a whole, no matter what group we’re talking about, there are many environmental services and benefits that they provide to us. I mean, it’s simply providing shade in the summertime, helping with soil erosion, helping to clean our air, to clean our water, provide habitat for wildlife, um, and food and, and resources for people and nature. But when we look at conifers, they provide services over the winter months when a lot of our trees are dormant and not active. Uh, they’re still providing air quality cleansing. Their leaves are still there, their needles are still on the trees. They’re acting as a visual barrier for our busy roads and buildings that we have around. And they’re also helping with sound buffering. Uh, and so those are things that are deciduous trees that lose their leaves. They’re not doing a lot for us over the winter months, but conifers are, and because they are very, uh, visible in the wintertime, a lot of our songbirds and, and mammal species sort of congregate in conifer stands to act as sort of protection from the winter winds and just shelter in general. 

When we think of where the owls are hiding out and where a lot of our birds are roosting at nighttime, it’s in those conifers over the winter months especially. Uh, so that’s, you know, sort of that year round benefit that we like to see on a tree. Conifers fit that bill. 

Josh Raulerson (7:09)

Is there also, like especially in an urban setting where there are more buildings, more people, is there an energy savings that’s associated with having a nice wind break, you know, near your home? 

Joe Stavish (7:17)

Historically, conifers have been used by farmers, uh, in their fields to block the wind over the winter months. You know, you had maybe corn or something growing in the field all summer, but that’s gone in the winter and you have a big open space. So if you look at a lot of the old farms, you know, the home itself is surrounded by conifer trees, simply has a wind break. Um, but that, that benefit, uh, translates over to our urban areas. We often plant deciduous trees for shade in the summertime, and then when they lose their leaves, we want that sun on our homes in the winter to warm us, but we don’t necessarily want the wind. So using conifers as a wind block can be very strategic to save on energy to block those drafty winds from coming into our old windows and such. Uh, and that’s a benefit of conifers. 

Josh Raulerson (8:01)

Another big benefit, and I’m interested in how conifers compare to other types of trees in this area, but as, as I’m sure you know, there’s a lot of interest in reforestation, afforestation type projects for the purpose of, you know, carbon sequestration. Is there any particular benefit to, to conifers for that application? 

Joe Stavish (8:17)

I don’t think there is a lot of carbon sequestration that would happen with conifers, just simply because of how their leaves are arranged and how they look. So being needles and holding those leaves up on there, um, from the research that I’ve done, I don’t, I don’t see them as like a top carbon sequester. There’s lots of larger leaf trees that do that, uh, that trap a lot of things in their leaves because of the size of the leaf and the leaf matter they have. Conifers are tricky because, uh, when they drop their needles, they do actually lose them throughout the year. Um, they do change the soil pH uh, they often make it very acidic under there. So if you’ve ever hiked through a forest with a lot of conifers, there may not be a lot of other things growing under them. Uh, so they kind of change the dynamic and the balance of nature. Uh, they’re still very important, but they’re definitely altering our soil below us and improving the soil for themselves. 

Josh Raulerson (9:04)

Well, I was gonna say, I use pine needles sometimes in my garden to kind of bring the pH down.

Joe Stavish (9:09)

Absolutely. If you grow blueberries, you wanna, you wanna pull some pine needles in and put those in the ground. There’s absolute benefits from there. We often don’t clean up the needles of conifers, and sometimes that’s where we have the disease issues, because if those needles are falling down and they have a fungus, those fungal spores are still in the needles, and people typically leave those under their pine trees, under their spruce trees. And then they become airborne and float back up and keep hitting that tree over and over again. So it’s not always recommended to clean up your needles under your evergreens, but if you know that there’s a sickness or a disease on your tree that’s, that’s helpful to move that out of there. 

Josh Raulerson (9:41)

So, I mean, is that kind of thing part of your sort of public education mission working with homeowners and like, you know, how to take care of your backyard conifers and, you know, and by extension, the population? 

Joe Stavish (9:51)

So our main goal is just all trees in general, but we definitely wanna focus on conifers because we’re the local urban forest nonprofit that really makes recommendations on the right tree for the right place. How to correctly select trees for your location, how to plant them properly, how to care for them long term, weeding, watering, mulching, pruning if needed. Uh, and we wanna make sure that people have many different species in the landscape because there is going to be a new pest, a new disease in the future that we don’t even know about. And so having many different trees is important for that. And also teaching people how they can participate in growing trees and contribute to their community for us. That’s our big mission. Uh, conifers fit in that role where we see people planting conifers, we see them popping up in our city and county parks. They’re in the landscape, they’re in people’s yards, um, but they’re not doing well overall. So we’re educating ourselves first so that we can take that information and sort of broadcast it to the larger audience so that we make more informed decisions on what types of trees we’re planting and where, so that we’re not over-planting a species that may be, won’t be predicted to do well under the future, uh, or just to have that diversity.

Josh Raulerson (11:02)

What are the species right now that look like they’re gonna be well positioned, bearing in mind the climate models and everything, what will our conifer population look like 10, 20 years from now?

Joe Stavish (11:10)

That’s the big question. And so one of the things we’re doing this year is bringing together experts from the region for our Conifer Symposium. Uh, and we have researchers from, you know, tree institutions, universities, state departments, forestry divisions, to sort of guide us in what their long-term research is showing in the broad forests and then how that relates back to our urban forest. We know that our, like top three conifers in the region, uh, that we see here in the Pittsburgh area, they’re not doing well. We think of our state tree, eastern hemlock, there’s disease issues and pest issues with that. We have eastern white pine, which has disease issues and fungal pathogens as well. And then spruce trees were probably the ones that first, uh, you know, people notice spruce trees dying all around the region. And so from there, where do we go? 

We want to bring in trees with needles because of the benefits they provide. So we have a long list of trees that we have been growing in our tree farm, which we call the Heritage Nursery. Uh, and we’re experimenting with a lot of these, and a lot of those trees have been in the ground, planted on properties for over 10 years, maybe close to 15. Um, but we almost need 50 or a hundred years to see how they’re predicted to do. So we’re bringing in researchers and experts to kind of look at those models and then experiment with this list of trees that we’ve been growing and putting out into the communities. 

Josh Raulerson (12:29)

What are the other regions, you know, that you’re looking at that maybe could be an analog and help you gain, gain some more insight about what might work here? 

Joe Stavish (12:36)

That’s challenging just because of where we’re located in the United States, but we’re definitely looking for, uh, species of conifers that are in southern states. So, you know, looking down in Maryland and looking at their loblolly pine population, bringing some of those up here. We’re also looking at more northern climates from, you know, north of Pennsylvania to see how maybe the seed that we collect and grow in our, in our nursery may be valuable to them as their climate shift as well. Uh, so we’re kind of early in the game in, in putting conifers out into the landscape. We haven’t been doing it more than 15 years. Um, but there are a lot of great trees that exist in our region that aren’t typical trees that you would find in Pennsylvania. So those genetics we want, we want to capture the genetics and continue to grow those species because they have been proven to withstand our summers and winter conditions, even though they’re not from Pennsylvania historically. 

Josh Raulerson (13:25)

Let’s talk a little bit about the symposium then, what you’ve got planned, what the goal is, who’s, who’s gonna be there. 

Joe Stavish (13:29)

Absolutely. So the symposium really has a, a few different goals. We wanna bring together experts and key stakeholders on conifer species because of the decline that we’re noticing. We also want to increase local knowledge of conifer trees and just awareness of their importance in our communities. Uh, we also want a better approach to tree planting and planning so that we have greater diversity for more resilient species into the future. Um, this is all funded through the Richard King Mellon Foundation, and it’s a learning opportunity for us to bring in experts. It’s also a way for us to guide our seed collection and the types of trees that we’re growing and propagating in our nursery. So, you know, we want to see how our seed stock can benefit those more northern communities, um, which conifers are performing best in our bioregion, uh, and sort of predicting ahead as climate change will increasingly change our, our plant landscapes. Um, and just understand what we have and what’s doing well. Uh, so we’re excited to host this. All of our staff will be there learning and participating, but we’re also gonna meet a lot of our great community partners that have been planting trees in the region for many years and have properties where a lot of these trees can go. 

Josh Raulerson (14:41)

Yeah, well, I wanted to ask sort of how public facing is this? You’re gonna have experts and, and tree professionals, but can anybody participate?

Joe Stavish (14:47)

For this first round, we’re not opening it up to the public, um, yet, uh, that may happen as we continue this on an annual basis. But right now, sort of our key stakeholders are gonna be, um, big landowners. You know, it might be the county parks or the City of Pittsburgh Parks, um, municipal forestry organizations, land trust groups, um, arboretums, local Audubon Societies, universities, uh, and many more. Um, so there’s lots of stakeholders that, you know, we we’re trying to invite to the symposium, uh, but it’s not just the average homeowner yet. We want to see what we learn from the symposium, take that information and create future programs for homeowners, for volunteers, for schools and community members. Um, based on our findings at this, this is a little more scientific of a program. Not that the average person won’t understand it, but we wanna figure out how to craft programs and plans moving forward that we then release to the communities.

Josh Raulerson (15:40)

Are you working with DCNR Bureau Forestry on these kinds of things? Obviously that’s a, a different context a lot of the time, but what, what are you comparing notes with those guys? 

Joe Stavish (15:48)

So, DCNR provides a lot of support for urban forest programs. Um, two of our speakers at the symposium are DCNR um, climate scientists. So we’re bringing them in to sort of show what’s been happening throughout the state forest systems. Um, we’ve also reached out to surrounding states to kind of see what are they dealing with, are they saying similar declines or similar issues? Um, but absolutely they have a lot of knowledgeable staff that are, uh, foresters, uh, in the community, but also just the research scientists that are studying forests and have been doing that for a very long time. Uh, two of their staff will be invited to our symposium as presenters and speakers. 

Josh Raulerson (16:23)

Allegheny County has certainly one of the largest, if not the largest county park system in Pennsylvania. What’s the opportunity there and what is the kind of the buy-in from the, from the county been? 

Joe Stavish (16:33)

Absolutely. So the county has been actively planting trees for a few years now, well, for many years really. Um, but the county is interested in how they can select species that will do well in the parks long term. Um, also have diversity. Uh, so when we look at a lot of our county parks that were planted 50, 60, 70 years ago, uh, we have a lot of very similar species in the forest and that’s not a problem. But as we’re moving forward, we wanna make sure that we’re putting in, uh, different species of trees, different groups of trees, and they’re very excited to work with us and learn and get trees from us to say, what should we be planning. We guide them often. They do a lot of the great work with volunteers and staff. Uh, but we just try to provide that local knowledge on what types of trees should go in the ground and then provide those trees because unfortunately not a lot of nurseries have the diverse types of conifers we need or want for our plantings, or they don’t have the quantities available that are needed for these large-scale projects. 

Josh Raulerson (17:26)

What is your kind of production setup? How many trees are you able to provide? 

Joe Stavish (17:30)

Well, conifers is a question mark cuz I don’t, I don’t have the number on that. But the way we’re set up currently, our heritage, our heritage nursery is located in, in Pittsburgh. We’re in the upper Lawrenceville area. Uh, we have over 110 different species of trees and shrub all collected and grown from local seed source. They’re not all native, but 95% of them are. Um, we also have to choose trees that are urban tolerant for a lot of our really tough growing conditions. Um, but currently there’s probably 30,000 containerized trees ready to go and probably another 20 to 30,000 seedlings that are just starting to germinate now, uh, that’ll be ready in a few years. And we’re always actively collecting, uh, growing germinating seeds and moving those out through our planting programs, school programs, tree adoption events, uh, and individual property owners that are placing wholesale orders with us. 

Josh Raulerson (18:22)

So clearly the emphasis right now is on kind of research and learning better understanding the problem, maybe looking a little bit further ahead or to whatever extent these things are happening now. Like what are the solutions gonna look like? What interventions are needed, what resources can be leveraged to make that happen? 

Joe Stavish (18:38)

So I think those, I mean, those are all wonderful questions, but thinking ahead of trying to get people actively participating in the community forest is sort of our goal. Also, getting people to understand the value and importance of trees. We work with a lot of people that love trees, but we also don’t work with a lot of people, uh, throughout the region because they have no interest in trees. They don’t understand the importance that those community trees bring to our homes, parks, schools, um, and properties. So for us, trying to get that information out on large scale and then get people excited. If we’re losing trees constantly, if trees aren’t looking good, that’s sort of like the doom and gloom idea and people are like giving up and we don’t want them to give up because there is hope, and people can make that difference. 

They can make that change. And so we’re trying to empower and excite people to participate in the next generation of trees that we may not see mature, right? They’re gonna go on the ground and they may take 70, 80 years to survive, but we want people to make educated decisions on where they’re planting trees, where they’re sourcing trees from, and hopefully caring for those trees. We see a lot of people plant a tree and walk away from it and hope for the best, and that doesn’t always happen. So active, uh, maintenance is often needed for our trees. And then even for people that work around trees and more of a traditional landscape setting, maybe it’s a homeowner or a landscape company not damaging the existing trees we have in our landscapes or recognizing when there is a pest or disease that’s affecting them, um, to maybe remove those trees so that the sickness or disease doesn’t spread throughout the entire community. Those are things that don’t always happen, and it’s unfortunate, but we want people looking at trees more and understanding that they can, they can participate in this. 

Josh Raulerson (20:19)

Are Christmas tree farmers a a potential partner in this effort? I realize that’s maybe not in, in and around Pittsburgh immediately, but certainly in western PA that’s —

Joe Stavish (20:27)

Pennsylvania is one of the number one producers and growers of Christmas trees and we often thought of them in the early planning stages of this symposium because they’re the growers. They’re growing a lot of different species, um, that’ll ultimately be used and cut from their fields. Um, but we have challenges growing conifers in our nursery. They sometimes do not survive the winter or they don’t germinate well or we can’t get seed from mature trees because they’re non-existent in our area or they’re too high off the ground and by the time the cones fall they’re empty. So we’re definitely looking at a lot of our big growers in the region in the future to communicate, go and tour their nurseries, their farms, see how they’re growing conifers and see how some of that information may benefit us — or on the opposite end, how we can start a lot of these diverse conifers and then send it out to these larger farms where they can grow them in the extended fields. Because everything we do is in containers. So we’re really only keeping them, you know, two to five years and then they have to go in the ground somewhere else, which is usually a planting or someone’s private property. Um, but large Christmas tree growers and, and growers in general, we hope to target, uh, to include in this and also to learn from them to see which species they’re phasing out. Which may be like the popular trend on what people wanna buy, but it also may be due to what does well in their fields and how they grow them.

Josh Raulerson (21:44)

I would guess they know something about what’s working and what doesn’t. 

Joe Stavish (21:47)

Absolutely. And uh, it’s funny to, to look at a native tree that’s grown in a tree farm versus in the wild. They often look much different because they’re sheared and pruned differently to give us the aesthetics for like a holiday tree. Uh, so people see the trees we grow and they say this, this doesn’t look like the, the tree that I usually buy for the holiday season. And we say, well this one hasn’t been touched, this is natural form. Uh, and some people are starting to get into that more and, and seeking out those types of trees for decorating.

Josh Raulerson (22:14)

The outcome of the symposium, will there be a report or some kind of summation of the knowledge and the learnings? What will be the next step from this process? 

Joe Stavish (22:22)

Yeah, so through the symposium, I mean we’re definitely gonna provide a lot of education to our participants and to our staff moving forward. Uh, we also want that community engagement, but we are gonna put together, uh, monitoring protocols so we can go out and collectively look at all the trees that have been planted through our programs with our partners over the past 10 to 15 years and be able to monitor them annually to see how they’re doing. We’re contributing to that science and understanding which species are doing well and which species maybe aren’t doing well. Uh, we’ve planted a lot of trees but there hasn’t been a monitoring program set up for them to see how are they doing. And we want that to continue. We also will have a written strategy on conifer tree species propagation and planting recommendations for individual property owners and land managers. 

The symposium is sort of the kickoff of this, so that is an outcome to host a symposium will probably end up doing that annually to update everyone and bring in more experts and, and advice for us. 

Another thing that’ll happen through the symposium, uh, once we understand what types of conifers we’d like to grow, that’s on us to go out and collect seed to figure out the best way to germinate and grow these seeds so that they are available for people to plant into the future. Because if we get the list of what we should plant, but then we can’t find those trees anywhere available for sale, then we’re not able to do that. Uh, so absolutely learning how we can better our nursery production for conifers so that we have better success there. And also use that nursery as an outdoor learning classroom. Bringing in volunteers and educational opportunities has always been a goal of ours, and that will be a direct result from our symposium here. 

Josh Raulerson (23:56)

What does that actually look like when you go out looking for seeds? You, you just, uh, you take off into the woods and—

Joe Stavish (24:01)

Yeah, that’s funny. Depending on what species we need, we sort of have our calendar of when we should be searching for seed. We always get permission to collect if it’s private property. Uh, we have permission with our city and county parks to work with the park rangers to acquire seed because the average person’s not allowed to collect and remove things from parks. Um, but for us it’s a, you know, some, some years are very successful. Some years, uh, the trees produce a lot of seed. Other years there’s nothing. And so we also wanna make sure that when we’re collecting seed, we’re not collecting from the same parent tree every year because we really want genetics. So we have to collect from, you know, five to 10 different known parent trees in the region, mix all those seeds together. Uh, and hopefully in the future those trees would be adapted more. 

But if you, you just wanna know like how we collect seed, it’s often just taking a hike. Walking, doing seeds scouting where we’re looking at trees. Making note of like what stage they’re in. Because if you collect the seeds too soon, they don’t germinate. Even though you could acquire the seed, it may not be a successful, uh, seed to germinate. So we have to take that into account. And then the big thing is like cleaning, preparing and, uh, stratifying those seeds in our refrigeration units, keeping them cold throughout the winter months so they don’t get tricked to be in the wrong schedule and then trying to germinate them. 

Germinating seeds is, is fun, but also challenging. Sometimes you’re mimicking what nature does and soaking them in sulfuric acid to mimic the digestive stomach juices of a bird. Uh, oftentimes you’re just putting ’em in the fridge and making them stay cold. Um, but we actually do a lot of volunteer seed collection events and we do trainings for people. So if you ever wanna come and learn, you can go for a hike with us. And then once you know what to do, we often get donations from individuals that are out hiking or have trees on their grounds to, to send seed to us. 

Josh Raulerson (25:41)

Well, I mean when you look at the, the monitoring program and that’s really built out and at the scale you want it to be at, is there gonna be a citizen science piece to that? Is there a role for, for volunteers or should, should we leave that to the pros? 

Joe Stavish (25:52)

I think that’s absolutely something we want to do with volunteers, with citizens, with people that are out in these spaces all the time and will use the experts to kind of come up with the guidelines and monitoring protocol and what should you look for when and how do you record that? How do you capture that data? Um, but there’s a lot of interesting research projects for university students, for professors, for forestry individuals. Uh, so we’re excited to sort of spearhead that and move that forward into the future. Uh, but absolutely citizen science is wonderful and we definitely want to encourage that, uh, as a great way to monitor what’s happening in our, in our landscapes. 

Josh Raulerson (26:27)

So the symposium is June 14th. What should people do if they would like to know more? Maybe find out if it would be, uh, something they should participate in. 

Joe Stavish (26:35)

So we’re officially calling our symposium the Allegheny County Conifer Symposium, but you can absolutely find the information on Tree Pittsburgh’s website. Uh, you’re correct. It is Wednesday, June 14th. It’s sort of an all day thing in Lawrenceville. Starts at 9:00 a.m., wraps up around 4:30. And then we move to Tree Pittsburgh’s campus for an evening reception and people get to tour the nursery, see our small collection of conifers that we have on site, and just have a nice evening, uh, talking about trees overlooking the Allegheny River. But check out Tree Pittsburgh’s website, that’s where we keep everything and host that. So yeah. 

Josh Raulerson (27:08)

Joe Stavish, director of education with Tree Pittsburgh. Thanks so much for your time today. 

Joe Stavish (27:13)

Thank you so much for having me and everyone out there that’s listening and planting trees.

Josh Raulerson (27:17)

The Allegheny County Conifer Symposium will be held June 14th in Pittsburgh.

Find information on the event and on TreePittsburgh’s many other programs and activities, at

You’ll find the link as always in the notes for this podcast episode, #192 of Pennsylvania Legacies, at

The website also has plenty of information on PEC’s reforestation programs, our work on trails and outdoor recreation, advocacy for clean energy and sound climate policy at the state and federal levels, our work promoting healthy watersheds, stormwater management, and AMD remediation, all at 

Back in two weeks with another episode of the Pennsylvania Legacies podcast. Until then, I’m Josh Raulerson, and thank you so much for listening. 

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