Student Research at the Arnold Arboretum

Posted by Chase Mason

At the Arnold Arboretum, three Boston University seniors are midway through a variety of new research projects at the intersection of plant physiology, ecology, genetics, and evolution. Sponsored by BU Professor Richard Primack, undergraduates Juliana Webber, Luca Russo, and Tessa Pliakas are set to begin their second semester of research with Arboretum scientist and Putnam Fellow Chase Mason.

Since September, Juliana has been examining the evolution of leaf flavonoids and other phenolics across diverse wild sunflowers (genus Helianthus) from across North America. Her results indicate large variation in secondary chemistry across wild sunflowers, and will improve our understanding of how allocation to defensive chemistry varies in response to plant adaptation to local soil and climate conditions.

At the same time, both Juliana and Luca have been examining the response of cultivated sunflower (Helianthus annuus) to hormonally-simulated insect attack. Juliana and Luca have been tracking how activating this internal plant defense response affects sunflower allocation to growth and reproduction, and leaf palatability to snails, grasshoppers, and caterpillars. In the coming months they will be examining in detail which classes of chemical defenses were most upregulated by defense induction, and together these multiple angles will tell us a great deal about trade-offs between growth, defense, and reproduction in an important oilseed crop.

In the lab, Tessa has been examining the carotenoid content of nearly a thousand samples of frozen sunflower petals, in an attempt to understand the genetic basis of flower color in cultivated sunflower. By assessing pigment concentration across an association mapping panel of several hundred sequenced sunflower lines, Tessa will begin the new year by mapping variation in petal carotenoid content to the sunflower genome, in order to describe the genetic architecture of this trait and begin the hunt for the candidate genes that determine whether sunflower petals are faint yellow, bright orange, or somewhere in between.

You can read more about Dr. Mason’s research and keep up to date on developments here.

The Warmest Autumn: plants and animals respond to record autumn temperatures

Posted by Richard Primack

According to the National Climate Data Center, the autumn of 2015 (September-November) was the warmest ever recorded for the lower 48 states and Alaska.

Tom Ashbrook for the National Public Radio program On Point interviewed me on the biological effects of this unusual weather event. My key point was that such extreme weather creates winners and losers, with many species increasing in abundance and others declining in abundance and even going locally extinct. 

You can also listen to the interview HERE.

Among the observations relevant to this topic:

Many plants are flowering and even leafing out at a time that they should be dormant. Shown above is a forsythia shrub in flower on December 19th in Newton, MA.

Annual plants such as the above yellow wood sorrel are still growing and not yet killed by frost; this plant even has a flower bud.

People are still harvesting plants from their gardens.  Our garden in Newton still has lettuce, Asian celery, and the mustard greens, shown here in flower:

Birds are also remaining north longer than usual. Massachusetts had many new records of late bird observations. In Saco, Maine, 6 species of warbler and other migratory bird species are still present in mid-December. You can keep an eye on autumn bird data collected by citizen scientists at eBird.

Butterflies and dragonflies are also still flying in December at various New England localitites when they normally would be dormant. Monarch butterflies have been seen in Vermont, Pennsylvania, and North Carolina. 

History and Ecology in Regensburg: a Town Linked to the Past

Posted by Richard B. Primack

In November, as part of my Humboldt Fellowship, I visited Peter Poschold’s research group in Regensburg, a town north of Munich in Bavaria. Peter’s group studies changing land use patterns and the distribution of plant species. 

The view from the top of a castle hill shows the intensive use of the region over thousands of years, from before Roman times and on to the present. Note the medieval bridge over the Naab River.

This region of Bavaria is also noteworthy for hundreds of fish ponds established 900 years ago by the Catholic Church and still in operation. Peter’s group studies the seed ecology of the plant species that germinate on the wet mud flats when the ponds are drained every few years for maintenance. 

Regensburg was founded by the Romans, and evidence of their walls can still be seen. I am standing in front of the original Roman gate built 2000 years ago and now a passageway between streets.  The town is dominated by one of Europe’s largest cathedrals, started in the 13^th century and only completed 600 hundreds years later in the mid-19^th century.  

A special treat just outside of of Regensburg on a hill above the Danube is full-scale replica of the Acropolis in Athens, built in the 19^th century as a memorial to the German-speaking people. The interior of the structure has a gallery displaying the busts of people who have made the greatest contributions to the German people.

Mokra Gora Nature Park in western Serbia: An Ecotourist Fantasy

Posted by Richard B. Primack

Earlier this month, I attended the World Biodiversity Conference in Mokra National Park in western Serbia. This is a beautiful area of rugged hills covered with pine forests and a few villages and fields in the valleys. 

The park is unusual in that much of the infrastructure was created in an exaggerated 1970s Serbian style as a set for a movie, and then was converted into a hotel, conference center, and restaurants.

The centerpiece of the park, which attracts large numbers of tourists, is a narrow gauge railroad and a series of train stations built just for the movie.

At the end of the conference, some of us went on a field trip that included a train ride.  Due to visa problems, many people were not able to attend the conference, and about half of the participants were from India.

After the conference I visit my colleagues in Novi Sad in northern Serbia. The highlight of the trip was a visit with grad student Tijana Radisic to a village park where about 80 long-eared owls nest during the day; at night they hunt in the surrounding fields. 

Thoreau’s continuing relevance to the modern world

Thoreau’s writings are not “Pond Scum”

Posted by Richard Primack

In a recent article in the New Yorker, Kathryn Schulz goes to considerable lengths to argue that Henry David Thoreau and his book “Walden” are not worthy of their high reputation in American society.  She accuses Thoreau of hypocrisy, a dislike of people, and being full of contradictions. Schulz’s major concession to Thoreau is that he is a keen observer of nature. 

However, in a rebuttal published in the Boston Globe, we argue that Thoreau’s writings of a century and half ago have continued relevance to modern society on topics such as greed and materialism, the value of higher education, and species loss. 

We also describe how we have used Thoreau’s detailed observations from the 1850s of the timing of flowering and leafing out of plants and the spring arrival of migratory bird species combined with modern observations to document the impacts of climate change. Plants in Concord are now flowering and leafing out about 10 days earlier than in Thoreau’s time, while birds are less responsive to a warming climate. Thoreau’s writings still inspire new generations of people to observe and protect nature, and have special value in climate change research. 

Autumn in the news

Posted by Amanda Gallinat

A recent article in New Scientist highlights our review of the effects of climate change on autumn, published earlier this year in Trends in Ecology & Evolution. The New Scientist article, by science writer Fred Pearce, is accessible and thoroughly researched, featuring top researchers studying autumn phenology such as Tim Sparks, Shilong Piao, Ally Phillimore, and others. You can read the full article HERE. 

Also in recent weeks, we were invited by the online publication Elsevier Connect to write a piece about our autumn review paper. You can find that article and participate in an already lively discussion about autumn by leaving us a comment HERE.

Luca Russo's Poster Presentation

Posted by Richard Primack

At a recent Undergraduate Research Opportunity Symposium, BU senior and Primack Lab member Luca Russo explained his undergraduate honors research on fruiting times and climate change to the Boston University research community.

Luca Russo describes his results to Primack Lab grad student Lucy Zipf

This project uses museum specimens of plants to examine how a warming climate will affect fruiting times, focusing on the differences between native species (blueberries, huckleberries, etc.) and non-native invasive species (bittersweet, buckthorn, etc.).