What is happening to our pines? [update]

The deep and diverse green-colored spring  in central New England is being interrupted in a jarring way.

Early yesterday afternoon (June 6, 2016) I heard a small crash against my office door. I turned and saw John O’Keefe. He asked if I had a minute (For John? Always). He asked if I had noticed the pines. I said I couldn’t recall anything particular. He then said they were shedding their needles, but that something unusual was happening.

In the late winter and early spring, eastern white pine (Pinus strobus) along roads and highways in snowy regions have foliar injury that is induced by the salt used to treat slippery roads. At some point during the summer most roadside white pines recover to a normal condition. What John observed is different.

He said he first noticed white pines on the road dropping needles and thought it was this annual injury that these trees incur from road salt. Then he said he didn’t think it was because the white pine in his backyard was dropping its needles. That pine is about as far from road salt as a yard tree could be.

As I drove home last night with these observations on my mind, a ca 47 mile drive on a country highway, Massachusetts’ Route 2 connecting Boston to western Mass, and then suburban streets, it became startlingly obvious: something is making pine trees drop most of their needles. Even tall trees where salt spray is unlikely to be important, pines are dropping their needles.

After driving the same route back this morning, I’d estimate this is happening to about 10% of the pines I can see along the road (perhaps only 8%, but perhaps a good bit higher). And, it isn’t just eastern white pine. Scots pine (Pinus sylvestris), red pine (Pinus resinosa), and what I guess is Austrian pine (Pinus nigra) are looking unhealthy. I also think I saw a couple of cedars in poor shape and a bare spruce not too far from my house.

As I drove in this morning, I wanted to capture some pictures. I didn’t have to go far when I saw the one of the worst cases. In an apartment complex in Acton, MA most of the pines in a roadside planting have shed all of their needles or are close to shedding all of their needles.

In an era of high volume trade, the number of diseases and insects impacting our forests is only increasing. Is this something new?

However, in the tree-ring samples we collected in eastern NY State, we see a tremendous drop in eastern white pine growth, beginning in 1948 and lasting for 6 years. Some trees in that population didn’t form a ring each year. In a sample size of 115 series, we “found” 87 missing rings. Most of those years of little to no radial growth occurred between 1948 and 1953.

Spaghetti plot of 115 ring-width series of Pinus strobus growth on Goose Egg Ridge, NY. The synchronous dip at the end of the 1940s is a time of significant number of missing rings.

 

Ed Cook said he saw something similar in white pine around that same period from samples he collected in the mid Hudson Valley of NY State. It doesn’t seem to be climatic or otherwise. Perhaps what we are seeing today is a repeat of that event? I hope it is a repeat and not something new.

I checked in with two colleagues in different parts of Ohio. Things look ok there.

Are you seeing this phenomenon? What species? Where?

UPDATE – June 7, 2016, 8 pm

The internet community is pretty awesome [Facebook, Twitter, here]. I’ve learned that it is in eastern PA, Vermont [thanks Shelly!], and perhaps in the Finger Lakes region of NY State. It doesn’t yet – yet – have the correct visa to get into Canada, eh?

Some great internet sources. First, a UMASS extension alert. Second, a study of the complex that is potentially behind this and the factors that might be driving it.

UPDATE – June 8, 2016, 9:32 pm

We went further west today – out to Florida, MA! Things looked relatively normal, but the yellowing pines were evident, especially around Charlemont and Buckland. In those areas we saw higher frequency of trees in needle decline, perhaps more than 10%. And, we saw saw the decline in stands pretty far from the road. The ‘other conifers’ of the title of this post might be wrong, so I’m removing it. Was mostly eastern white pine with the decline today. Pictures from June 8, 2016 immediately below. Pictures from Acton, a suburb of Boston, below those pictures.

 

 

Below are pictures of eastern white pine in Acton, MA from June 7, 2016.