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Many started as Christmas trees. Now the Valley's big, beautiful Aleppo pines are in decline

By Lauren Gilger
Published: Wednesday, December 6, 2023 - 11:37am
Updated: Thursday, December 7, 2023 - 7:25am

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Fallen Aleppo pine tree in central Phoenix after a summer storm
Christina Estes/KJZZ
This 50-year-old Aleppo pine in central Phoenix was toppled by a summer storm in 2021.

Drive around metro Phoenix right now, and you might notice the first trees starting to change color as fall starts to kick in. But look closer and you also might notice that some trees that aren’t supposed to change color are turning brown. 

That’s true for several non-native species of trees this fall after the brutal summer we all experienced, but none more so than the big Aleppo pine trees that dot the city, especially in older parts of town. 

It’s hard to make sense of why pine trees ended up in the desert, but it turns out this particular species thrives here — unless it gets too hot, which it did this summer. Now, we’re seeing the big, beautiful old pine trees being cut down all over the Valley. And Richard Adkins is involved in a lot of that. 

Adkins is the urban forester for the city of Tempe and he’s considered the local expert on Aleppos. The Show spoke with him more about why so many of these beautiful trees are going down.

RICHARD ADKINS: Well, the Aleppo pine — Pinus halepensis is the scientific name — it's one of the more desert tolerant pines that are grown around the world. It’s from the Mediterranean region originally. And out of four or five pine species that grow here in the Valley, it is probably the most hardy.

LAUREN GILGER: Yeah. OK. So here because they do well here or have at least for a long time done well here. Is it true — there’s this kind of legend out there that they were Christmas trees that people planted. Is that true?

ADKINS: Yeah. Originally back in Syria, during that time it was, as the legend goes that, yes, they were used for decorating to service one of the Greek gods. And that kind of just held over and became taken by the Christians to be decorating the trees. And they became, one of the first Christmas trees is supposed to be the Aleppo pine.

GILGER: So people in Phoenix — you know, 60, 70 years ago — would be planting their Christmas trees. And that’s how these ended up here?

ADKINS: A lot of the time that's true. Even today, that's still the case. I have people call all the time because people like live Christmas trees, and they want to donate it to the city park after they celebrate the holidays. So a lot of the pines when I go out and I talk to a lot of residents, a lot of them over the years — over the ’50s, ’60s, ’70s — where it was their family Christmas tree. And they planted it in the back or the front yard.

Richard Adkins, Tempe Urban Forester
City of Tempe
Richard Adkins

GILGER: And now they're really big. But we're starting to see them die off, it seems. Tell us what's happening here. Like, was it the heat of this summer that seemed to push them over the edge?

ADKINS: Well, I'd say not just this summer. I mean, we've been in a prolonged drought and, you know, summer three years ago it was really dry and hot. And then again this year it was really dry and hot. And we have very limited rainfall so far. But you’ve also got to look at the nighttime temperatures. I mean, we were in the mid to high 90s for a lot during the month of July. So a lot of the stress over the years of drought has really started pushing some of the larger pines to their limits.

GILGER: So it sounds like this has been going on for some time, although I’ve just started to notice it really this fall after this most recent summer. Probably more of them are kind of hitting that point. Is it age, too? Is it just that some of them are getting old?

ADKINS: I'm glad that you brought that up. That is a big point. Generally in the Mediterranean region, where the pines are from, the oldest trees there are about 200 years. Here in the Phoenix area, 50 to 100 is about the extent that you’re going to find them. Some of the oldest ones now in central Phenix are around 80 or 90. Yeah. So age, natural senescence of the trees, that’s also a big factor because a lot of these trees were planted ’40s, ‘’50s, ’60s. And depending on the conditions where they are, age is a big factor along with the heat.

GILGER: OK, so they're getting older. It's getting hotter here. The climate is changing here. Those are factors. Is there anything you can do to save one of these? Like if you see in a Tempe city park, like beautiful big old Aleppo pine starting to turn brown, like, can you bring it back from the brink? Is it about watering?

ADKINS: You can with watering, though where you’re watering the tree is very important. That’s why I try to work with a lot of residents is making sure that you're watering around the crown drip line, which is the edge of the crown where the needles are and not just up against the trunk. And see, another thing with that, the soil becomes very warm here as well during the summer, especially if you’re in rocks or gravel. A lot of front yards are. And that’s something, a lot of people have started doing turf conversions over the last five years or so. And putting in synthetic turf or putting in rocks where they had grass and flood irrigation, and the roots just cannot take that kind of a transition. So we end up losing a lot of the mature trees.

GILGER: So we're starting to see them die off. What’s this looked like for you in the City of Tempe? Like, are you taking down a lot of these big old trees pretty often nowadays?

ADKINS: Unfortunately, yes. And not just pines, but many of the other older species, because the stress that is brought on by the heat as well as age, as we discussed, that brings other insect pests. And there's some new pests that have we’ve discovered over the last five years that once the pines become a little bit stressed, that puts out a calling, so to speak, and then the beetles will come to them. And once you get to that point, there’s very little you can do.

But we try to keep our soil moist, make sure there’s a homogeneous moisture around the root zone. We’ll put down some mulch if we can, because that helps protect the soil and keep it cooler. But sometimes the age has reached, and it’s time for them to go.

GILGER: That must be kind of sad. Like, how do you feel about it? Like cutting down these big, beautiful trees in this place where we need shade? We need trees, right?

ADKINS: I like trees better than most, I’ll say. But sometimes I have to look out for the liability of park patrons and city residents. And sometimes I leave some of the older trees, actually, for wildlife habitat. So you just got to look into all the risk factors there. Sometimes, though, you need to remove.

GILGER: OK, so what about for a homeowner? If you have one of these in your yard, that’s going to be expensive to take down. How do people do that?

ADKINS: It is quite expensive, actually, and it’s in a smaller space. So it becomes a technical removal. And a lot of times, cranes need to be involved. So it can run many thousands of dollars. Yeah. Have one of these older trees. And that's when I was talking about the turf conversion. A lot of people will make that turf conversion and not really think it through that The trees still need some water. Five years later, they're looking at a multi-thousand-dollar bill to remove this tree.

GILGER: Man. Man. So I wonder about that shade question, right? Because we need this kind of urban tree canopy, this shade that we talk about a lot in terms of heat mitigation. What are the other alternatives? You’re in an interesting position as the arborist for a desert city, right? I mean, what trees do well, how should we transition and look forward to the next 50 or 80 years?

ADKINS: And that’s a good point. I mean, we try to maintain the mature trees that we have because they provide more benefit and value, obviously, because they’re more established and larger. But we also have to plant new trees. You’ve got to make some intelligent design choices when you're looking at what species that you want to plant.

So I've got a palette of species that I'm looking for now that are more climate adapted. Some of the eucalyptus species are good, the acacia species are good. The elm species that we have here are fine. They do need a little bit more water. Some of the pistache are fine. And then any of the native species, I mean, people always want to plant natives, which are great, but you’ve got to remember native have spines and thorns on them, and you got to be a little considerate of where you’re planting them.

But the mesquites, the palo verdes, the ironwoods, some of the desert willows — very nice trees. And they’re still fruit trees.

GILGER: Yeah. So do you feel like, as an arborist in the desert here, you are sort of always kind of adapting, especially as our city gets hotter and we are dealing with climate change in a real way? Do you think the city will look different in terms of the tree canopy in the future?

ADKINS: I think it's definitely going to look different. We’re talking about pines to begin with. I’ll be very surprised in 25-30 years if we have many pines growing here in the Valley. That’s just the way the change is. Yeah, I think we’re going to go — this is my opinion, and from the studies that I’ve read and work that we’ve done in the field — we're going to go to a smaller-stature tree, maybe 25, 35 foot tall; more widespread canopy. I think that's kind of where we’re going to go. These larger trees that we have now, that’s going to be hard to maintain those, especially with our water resources. We’ve got to be very smart in how we’re moving forward with that.

GILGER: Do you think that’s a good thing, or is it sort of heartbreaking that some of these big, beautiful trees won't be here in the future?

ADKINS: Well, you look at where we started when it was a desert. Those weren’t here then. It was more of the desert material. We had saguaro forests with big mesquites and the ironwoods and the palo verdes, which are more smaller stature trees growing close to the ground, conserving soil and moisture resources. I think that’s kind of where we're going back to.

GILGER: OK. So it's almost a cyclical thing there. OK, Richard Adkins, consulting arborist and urban forester for the city of Tempe, joining us to talk about the decline of these beautiful big Aleppo pines. Richard, thank you for coming in. I really appreciate it.

ADKINS: You’re very welcome. Thank you.

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