Greetings Hubbard Brook community,
In sure signs of spring, birders and even a few birds have arrived at Hubbard Brook. Birds and birders alike are keenly watching the trees for leaf-out. The updated phenology forecast has retreated by one day since the last forecast. From
where I sit near Hanover, where the maple and beech leaves popped their buds this week, it is so hard for me to imagine that leaf-out on the bird plots is still 12 days away that I did some checks on my algorithm, but I found no errors. The forecast is for
leaf-out on 16 May, with the birds there waiting, followed by rapid leaf expansion over the next 11 days. If, as my intuition suggests, the forecast date turns out to be later than the truth, then we will be looking closely at the deviation to improve our
model for the next years.
Based on our current best phenology models (after Lany et al. 2016), temperatures to date this year, and the 10-day forecast as of
1 May 2024, predictions for the mid-elevation bird plot (490 m asl) are:
·
Budburst = 16 May,
·
90% completion of leaf expansion = 27 May,
·
Median date of arrival and first clutch initiation for Black-throated Blue Warblers = 13 May and 2 June, respectively.
More details in enclosure.
Matt
From: HubbardBrook <hubbardbrook-bounces@lists.sr.unh.edu>
On Behalf Of Matthew P. Ayres via HubbardBrook
Sent: Wednesday, May 1, 2024 19:29
To: Hubbard Brook (hubbardbrook@lists.sr.unh.edu) <hubbardbrook@lists.sr.unh.edu>
Subject: [HubbardBrook] Hubbard Brook phenology forecast
Greetings Hubbard Brook community,
We are pleased to provide an updated phenology forecast. I was impressed by some of the recent warm days (and nights!), but, contrary to my impressions, the predicted date of budburst has retreated by three days since the last forecast.
Under the update forecast, the median date of arrival by black-throated blue warblers will now precede budburst by about 3 days, and budburst will be about two days later than that expected for 2024 under the 70-year records. (Spoiler alert. Don’t worry about
the birds! They are adapted to interannual variation in when the summer begins.
This weekend just past, I was able to validate that the trees had still not leafed out near the bird plots. If you scroll below, you can find an image taken near Weir 6 on Sunday afternoon.
Based on our current best phenology models (after Lany et al. 2016), temperatures to date this year, and the 10-day forecast as of
1 May 2024, predictions for the mid-elevation bird plot (490 m asl) are:
·
Budburst = 15 May,
·
90% completion of leaf expansion = 26 May,
·
Median date of arrival and first clutch initiation for Black-throated Blue Warblers = 12 May and 1 June, respectively.
More details in enclosure.
While you are enjoying the spring, consider that already last fall each bud on the sugar maples, beeches, birches, etc. already contained all of the cells required to produce the cluster of leaves that will be rapidly produced in the next
weeks by each bud. Here is a time lapse video of a sugar maple bud in my backyard last spring.
Sugar maple bud to sugar maple leaves
The process depicted occurred over about 230 °days > 4 °C
Feel free to share this with anyone who may be interested. We will aim to provide continuing updates of the forecasts.
Enjoy the spring! There’s only a few days a year like this.
Matt
Matthew P. Ayres (h/h)
Professor of
Biological Sciences; Co-Chair
Graduate Program in Ecology, Evolution, Environment & Society; Senior Faculty Fellow
Institute of Arctic Studies
Life Sciences Center
78 College Street
Hanover, NH 03755 USA
603 646-2788