Thursday, November 14, 2019

Stomate Science at the Arnold Arboretum

Posted by Emily Auker


“Every blade in the field – Every leaf in the forest – 
lays down its life in its season as beautifully as it was taken up.” 
Henry David Thoreau

Stomates are pores on a leaf’s surface that provide an interface between the leaf and its surrounding environment by allowing carbon dioxide to enter the leaf and water vapor and oxygen to exit. The density, size, and distribution of stomates on a leaf can impact photosynthetic rates. 

This past spring and summer I took measurements of photosynthetic rates from several species found at the Arnold Arboretum.

Having fun measuring photosynthetic rates!

I also collected leaves from each of the species to take a look at the stomates under the microscope. This can be done using leaf peels, which are made by painting leaf surfaces with clear nail polish, or with bleached leaves which have had the color removed from them.

Here you can see the leaf being measured clamped in the machine

With this project, I’m hoping to find a correlation between the photosynthetic rates and anatomy in leaves found in different light environments around the Arnold Arboretum.

The ovular openings pictured here are stomates under the microscope

Thursday, October 24, 2019

Heat Waves in Brookline

Richard B. Primack and Audrey S. Garon

“Is not all the summer akin to a paradise?”  Henry David Thoreau

This past summer, Brookline experienced a brutal July heat wave with temperatures over 90 degrees four days in a row, reaching a high of 97 degrees.  Heat waves  are increasing worldwide, and are more intense in places like Brookline due to roads, parking lots, and buildings that absorb heat, and fewer trees for shade.

Originally from Texas, Sean Roberts running laps at Amory Park during the July heat wave.

Pete Rittenburg, Director of Athletics at Brookline High School,  says that sports programs adjust by  “avoiding the heat of the day and practicing either in the morning or late afternoon.”

The very hot day does not bother these tennis players, who grew up in Brazil.  

Dr. Swannie Jett, Brookline Health Commissioner, warns that the risk of heart attacks and asthma increases for senior citizens when temperatures go above 85 degrees.

Many people lack air conditioning to deal  with the heat.  Brookline resident, Katie Eng, doesn’t have any air conditioning because “Getting an apartment that comes with winter heating and summer air-conditioning is a luxury that many of us cannot afford.”

Tamara Hurioglu found that during the July heat wave, “Even with four window AC units running all day, it was 89”  in some areas of her top floor apartment.

Caroline and Jake Berchuck, from North Carolina, out walking their dog in the noon sun. 

In coming years, Brookline residents will experience more heat waves because of climate change.  It will be like living in North Carolina or Texas, rather than Massachusetts.

A longer version of this article originally appeared in the Brookline Tab.

Monday, October 14, 2019

Primack Lab in the News

Posted by Richard B. Primack

What have we to do with petty rumbling news? We have our own great affairs. 
Henry David Thoreau. 

Our research on climate change, Thoreau, Walden, sporting events, and plant ecology continues to attract public attention. Here is a sample of articles from the past year:

• Is Climate Change Ruining Fall?
by Marina N. Bolotnikova, Harvard Magazine, 9.26.19
Primack discusses the effects of climate change on fall foliage and New England’s trees.


• Global Warming Clues from Henry David Thoreau
NPR Living on Earth: Week of June 7,  Don Lyman. 2019  
During an interview at Walden Pond, Primack explains how Thoreau’s observations can be used to show the effects of climate change on plants. 


The fire cherry (Prunus pensylvanica) was one of many species for which Henry David Thoreau tracked both the flowering and leafing-out dates more than a century and half ago. (Photo: Dan Mullen, Flickr CC BY-NC-ND 2.0, Caption: NPR)

• Science and Culture: Journal entries, maps, and photos help ecologists reconstruct ecosystems of the past. 
By Carolyn Beans, PNAS December 26, 2018 
In this article, Primack describes the value of historical documents in detecting the effects of climate change. 


• Tracking climate change through Henry David Thoreau's notes. 
Boston 25 TV News
In this interview on the edge of Walden Pond, Primack talks about using Thoreau’s records in climate change research. 


Primack in a still from the Boston 25 news story

• Undergraduate research at BU – Invent the future. 
In this interview on the BU website, Linnea Smith and Richard Primack explain the value of students working with professors in Boston University’s Undergraduate Research Opportunities Program (UROP). 


• How Thoreau’s 19th-Century Observations Are Helping Shape Science Today: For one thing, they tell us that plants aren’t blooming when they used to at Walden Pond—or most anywhere else. 
By Evan Nicole Brown, July 9, 2019, Atlas Obscura 
Atlas Obscura is an on-line magazine with unusual stories about iconic places around the work. In this article, Primack reports on the value of Walden Pond as a climate change indicator. 


A statue of Thoreau with wildflowers 

• New England Is Losing Its Native Plants. Researchers Say It’s Time To Stop And Smell The Wildflowers. 
By Lexi Peery, June 06, 2019, WBUR Radio
In an interview on WBUR Radio, Primack provides an overview of the loss of wildflowers from the forests and protected areas of New England. 


• What Will Climate Change Mean for Your Favorite Marathon?
From surging waters in the Southeast to wildfires in the West, here’s how a warming planet affects your racing.
By Cindy Kuzma, August 28, 2018, Runner's World
Primack describes how a warming climate and weather events affect the running times and experiences of marathon runners. 


Tuesday, October 1, 2019

Science Takes to the Streets

By Tara Miller



"All men recognize the right of revolution; that is, the right to refuse allegiance to and to resist the government, when its tyranny or its inefficiency are great and unendurable."
- H.D. Thoreau


On September 20th, kids around the world took to the streets, marching out of classrooms and schools to teach us a lesson. We have not done enough, and we must continually push for bolder, more ambitious action on climate change.

Young students organized, led, and showed up for the Climate Strike in Boston


I was one of 10,000 people in Boston, and 4 million around the world, joining students in their call for stronger action on climate change. 

Protesters march from City Hall

We study how climate change is affecting our ecosystems, but when politicians ignore that science, it is our responsibility to make them listen or to replace them.

Make a difference with how you commute, make a difference with what you buy (or don’t buy!), make a difference with what you eat, make a difference with what you tell your representatives, and for goodness' sake, VOTE.

Protesters arrive at the State House

"You must unite behind the science. You must take action. You must do the impossible. Because giving up can never ever be an option." 
– Greta Thunberg

Wednesday, September 25, 2019

Are scientific editors reliable gatekeepers of the publication process?

Posted by Lucy Zipf

The goal of the peer-review process of journals is to make well-founded and consistent decisions and publish high-quality science. The scientific community assumes the publication process is reliable and fair, with the best papers being published only after rigorous review. Scientific editors act as “gatekeepers” in this publishing process, deciding whether a paper is even sent out for peer review, or alternatively “desk rejected”, that is returned to the author without peer review.

The Biological Conservation editorial team often acts as an editorial gatekeeper, as shown in this 2018 photo in front of an actual gate. From left to right:  Danielle Descoteaux (USA, publisher) Richard Primack (USA),Robin Pakeman (UK), Tracey Regan (Australia), Vincent Devictor (France), Richard Corlett (China), Liba Pejchar (USA), Bea Maas (Austria) and David Johns (USA). 

We recently assessed the consistency of editors’ desk decisions and published our findings in Biological Conservation. Ten editors of Biological Conservation evaluated forty manuscripts that had been previously submitted to the journal. 

Frequency of agreement among editors to send to manuscripts for review in 2018 (as a %). The green portion of a bar represents papers that editors sent out for review in 2017, while the red portion represents papers that were desk rejected in 2017. A high agreement indicates that 70-100% editors agreed in 2018 to either reject or review a manuscript. Low agreement indicates 40-60% agreement among 2018 editors. It can be seen that the decisions made in 2017 were largely supported by editors in 2018.

Overall, we found that editors are reasonably consistent in their decisions to send a paper out for review, or to desk reject it, and that they agreed with past decisions. However, disparities in agreement with decisions reveal the unsurprising subjectivity editors bring to the process.

Thursday, September 19, 2019

Leaf longevity published!

Posted by Linnea Smith


“However mean your life is, meet it and live it; do not shun it and call it hard names.”  
Henry David Thoreau. 

Our leaf longevity project for my BU Biology honors thesis and Sarah Pardo’s BU Academy senior thesis has now been published in the international journal Oecologia.  The article, titled “Leaf longevity in temperate evergreen species is related to phylogeny and leaf size” is featured as “Highlighted Student Research.”

In this project we used the living collection of the Arnold Arboretum in Boston, Massachusetts to determine the leaf longevities (LL) of 169 temperate evergreen species. To our knowledge, this is the largest dataset of its kind, collected from one site using a single unified method.

Richard Primack (left) and Linnea Smith (right), demonstrate measuring leaf longevity by counting leaves across different aged branch segments.

We found that LL has a strong phylogenetic component – different genera have different LLs (see the figure below) – and conifers with longer needles tend to have shorter leaf longevities. Of the 169 species we investigated, Labrador tea (Rhododendron tomentosum) had the shortest LL (only 1.4 years); the oldest leaves we found were of Taurus fir (Abies  cilicia), living for an average of 10.5 years.

Different genera of evergreens have very different average leaf longevities, varying from 2 to 6 years. The number of species examined is listed above each genus. From shortest to longest leaf longevity, the genera are Rhododendrons, Ilex (holly), Pinus (pine), Taxus (yew), Tsuga (hemlock), Picea (spruce), and Abies (fir). 

Because leaves play a vital role in the carbon cycle as well as other ecosystem functions, understanding their dynamics (such as LL) is important to better constrain carbon budgets and ecosystem models.