A visual art project at Walden Pond

Posted by Lucy Zipf

On a beautiful September Sunday at Walden Pond, Richard and Dan Primack and I met Amy Howden-Chapman, a New Zealand artist who has recently relocated to Connecticut. Amy produces visual art pieces that detail anthropogenic change in our world in a manner that she describes as “more poetic and less documentary based.”

Amy interviewing Richard at historic Walden Pond

Amy’s current project examines the effects of a warming climate on Walden Pond and its surroundings, which she read about in Richard’s book Walden Warming. The goal is to encourage viewers to see examples of climate change in the plants and animals of their immediate environment, not just in far-away images of melting glaciers and hungry polar bears.

Amy and Richard at the site of Thoreau's cabin

We spent several hours walking along the trails surrounding the pond and talking about the changes we have already observed and that we expect to see in the coming years. We focused especially on invasive plant species and their competitive advantages over native species.

We look forward to seeing Amy’s project. Her completed works are available on her website:

http://amyhowdenchapman.com/

Going to Gottingen (pronounced “Gert-ing-en”)

Posted by Richard Primack

I recently attended the annual conference of the ecological association of Germany, Austria, and Switzerland in Gottingen, Germany. Gottingen is an ancient walled town and home to one of Europe’s oldest and most distinguished universities. I presented one of the keynote talks on “The Hottest Topics in Conservation Biology”.

On the last day of the conference, we went on a field trip to Hainich National Park, right in the center of the country, which is the largest continuous stand of deciduous forest in Germany. The stand consists of 16,000 ha (an area equal to about 64 square miles) of hilly beech forest; not very large by USA standards. Outside the forest is predominantly agricultural countryside. Hainich was maintained as a forest because it was a military training area for the East German and Russian armies. 

A popular feature of the park is an amazing canopy walkway system that is hundreds of yards long and which allows visitors to walk around the top of the forest. The walkway features a giant tower giving a 360 degree view of the surrounding countryside.

Most of the walkway system is very gentle. Recently the park has installed a more challenging set of rope walkways for more adventurous visitors.  

The park is also home to a large experiment investigating the relationship between the diversity of species, land use intensity, and the ecological functions provided by the environment. In the photo above, a researcher explains an experiment examining the rate of decay of different log types, the types of insects living in different types of decaying wood, and the rate of carbon dioxide released by the wood (as measured by bags placed over the gray boxes). 

South African Biodiversity and Conservation: A mighty fine fynbos

Posted by Richard Primack

"One hastens to southern Africa to chase the giraffe; but surely that is not the game he would be after. " 

-Henry David Thoreau, Walden

Thoreau argued that we should explore our inner worlds of self-knowledge rather than rushing after superficial travel experiences. Perhaps ignoring his advice, I am visiting Cape Town, South Africa, for 10 days. I am learning about the world’s greatest concentration of plant species, meeting conservation biology colleagues, and trying to develop a conservation biology textbook for Africa. 

On my second day in Cape Town, I visited a section of fynbos, a lowland shrub ecosystem with an amazing diversity of plants species, many of which have very restricted ranges. The fynbos has over 9000 species, most of which are found nowhere else in the world, in an area the size of the Netherlands. Table Mountain is a recognizable feature, towering above the city of Cape Town.  

The fynbos is especially noteworthy for an abundance of species in the Proteaceae with beautiful flowers. This particular individual was planted in a restored area from which non-native invasive species have been removed.  

The characteristic flowering Protea head with hundreds of individual flowers. 

Above, two colleagues hold a map showing places where stands of non-native invasive Acacia shrubs are being removed from fynbos vegetation. Areas cleared of Acacia shrubs can be seen in the background.

Invasive Acacia shrubs can form a pure stand and outcompete native fynbos species. 

Methods to control invasive Acacia shrubs include (1) spreading a fungal disease that forms growths on the stems and weakens the plant, (2) releasing a beetle that eats its seeds, and (3) chopping down and burning plants. 

Examining historical fruiting times with herbarium specimens

Posted by Luca Russo

"Going a-berrying implies more things than eating the berries"

-Thoreau, from Huckleberries

Climate change may be affecting the fruiting times of plants in New England. If so, this would have consequences for the birds that eat fleshy fruit during their time of migration.

Ripe fruits on a specimen of Berberis thunbergii from the University of Connecticut herbarium

For the past year, Amanda Gallinat, Richard Primack and I have been evaluating herbarium specimens for about 60 common native and nonnative invasive species in New England for fruit ripening times. To understand how fruiting times have changed over time due to a warming climate, we have examined these museum specimens, which range in collection dates from the 1850's to present.

A full ripe specimen of Berberis thunbergii from the University of Connecticut herbarium online

In addition to the date the species was collected, each label on a specimen also provides information on the collector and location where the specimen was collected. We are especially interested to know if native species and invasive species are responding to climate change differently across the New England landscape.

A closer look at the label on the Berberis thunbergii specimen above 

Substantial variation in leaf senescence times

Posted by Amanda Gallinat, photos by Richard Primack

"October is the month of painted leaves.  Their rich glow now flashes round the world." 

-Henry David Thoreau, "Autumnal tints” in Excursions

In recent years, the Primack lab has worked in partnership with 5 other research groups at botanic gardens around the world to monitor the timing of leaf senescence (leaf color change and leaf drop) across a wide range of species. The results of this international collaboration have been published in Annals of Botany, in a paper led by Zoe Panchen of Carleton University.

Prunus sargentii leaves changing from green to yellow and red coloration.

The paper, entitled "Substantial variation in leaf senescence times among 1360 temperate woody plant species: implications for phenology and ecosystem processes" demonstrates that autumn leaf senescence dates vary broadly between species and botanic gardens. Within each botanic garden, the sequence of leaf senescence was fairly consistent between years, but did not have a strong phylogenetic signal. 

Leaves senescing in the Morus section of the Arnold Arboretum in Boston, MA

These results are in stark contrast with the results of a similar study on spring leaf-out times that our botanic garden collaborative published last year, which showed that the sequence of leaf-out is largely consistent between years and locations, and contains strong phylogenetic patterns. We conclude that while leaf-out is strongly driven by spring temperatures, the lack of patterns in leaf senescence timing means it is likely driven by a combination of local environmental factors, including soil moisture, frost, wind, and temperature.

Hossein Akhani from Iran visits Primack Lab

Posted by Richard Primack

In early July, Prof. Hossein Akhani from the University of Tehran visited the Primack lab to discuss our current project to produce an Iranian edition of A Primer of Conservation Biology. Prof. Akhani presented an engaging seminar to the BU Biology Department on “The ecology and conservation of saline ecosystems in Iran with a focus on Lake Urmia, the largest lake in the Middle East”. The environmental damage being done to Lake Urmia through diversion of water is reminiscent of the better known example of the disappearance of the Aral Sea.  

Two highlights of his visit were a trip to the Arnold Arboretum with BU undergrads Luca Russo and Lucas Stegman to monitor fruit maturation, and an excursion to Plum Island to observe coastal vegetation.  

Prof. Akhani’s visit coincided with the final round of international negotiations regarding Iran’s nuclear program, and allowed us to get a better idea of the Iranian perspective of these complex issues.

The Primack Lab visits Manomet for spring migration

Posted by Amanda Gallinat

Last month, the Primack Lab visited Manomet Center for Conservation Sciences in Plymouth, MA to see the landbird banding program in action. This year is Manomet's 48th year of banding, and their long-term records of landbird passage dates have allowed us to explore how the timing of bird migration is changing over time and in response to climate change, in both spring and autumn. 

This American Redstart was captured during our visit to Manomet's banding lab

Our group included Richard Primack, myself, and two undergraduate assistants in the lab, Luca Russo and Lucas Stegman. Luca and Lucas have both assisted with sorting and identifying seeds from songbird fecal samples collected at Manomet last autumn. During our visit, they got a chance to see the banding process first-hand, walk the net lanes at Manomet, and observe many of the species that provided the fecal samples we've been sorting.

Lucas observes a House Wren before it is released by the banders

Luca and bander Mattie Vandenboom with a Gray Catbird that has just been processed

We are grateful to banding director Trevor Lloyd-Evans and the spring 2015 banders for their wonderful hospitality, and we look forward to returning for more banding in the fall!