Northern species declining in New England

 By Richard B. Primack  

 

“What a fine & measureless joy the gods grant us thus, letting us know nothing about the day that is to dawn.”

-Henry David Thoreau in his Journal. 

 

In a recent paper in Northeastern Naturalist, Robert Bertin and Caitlin Spind demonstrate the effects of climate change on the flora of New England. Using a combination of historical data from herbarium specimens and current survey records, they found that rare northern species are most likely to persist in cooler towns, whereas rare southern species showed no such pattern.  

 

For rare northern species, towns where populations persist are cooler than towns where species have been lost. For example, current populations of Vaccinium vitis-idaea (mountain cranberry) are found in towns that are 2 degrees C cooler than towns where populations have been lost.

Rare species also showed a tendency to be lost from towns with a higher human population density, indicating that direct human influence was an additional factor in population decline.  

Mountain cranberry has tended to decline in warmer sites.

Further studies are needed to determine the mechanisms behind these changes in distribution of rare species. Is it due to drying out of habitats and heat stress during the summer? Lack of snow cover in winter? Mismatches with tree leaf out and pollinators in the spring? Or something else? 

 

Here is the reference: 

Bertin, RI, and CG Spind. 2022. Are rare northern plant species retreating from the southern edge of their ranges in southern New England?  Northeastern Naturalist 29: 393-414.  

Link

Threats to Food Security

 By Richard B. Primack 

 

“All questions rely on the present for their solution. Time measures nothing but itself.” 

-Henry David Thoreau in A Week on the Concord and Merrimack Rivers.  

 

A recent issue of Boston University’s Arts & Sciences magazine asks the Big Question: What is the greatest threat to human health from climate change? 

 

The greatest threat from climate change will likely be the danger it poses to plants and our food security. Throughout the world, stable crops such as wheat, corn, rice, and wheat will be harmed by the combination of heat waves and drought associated with climate change. This decline and loss of harvests will lead to sharply rising food prices or no food, hunger, starvation, and emigration.  

 

Corn crops will be harmed by droughts.

 The solution is to transition to an economy in which fossil fuels are greatly reduced, and alternative energy sources, such as wind, solar, hydroelectric, geothermal, and perhaps nuclear power are greatly expanded.  

 

Solar power is part of the solution.

 The main barrier to implementing these solutions is political. Individual people need to become involved in the political process, and to urge leaders to takes stands, to pass legislation, and to form alliances locally, nationally, and international to address climate change. Most importantly, the world needs an agreement between the US government and the Chinese government to reduce the production of greenhouse gases. 

 

President Biden and President Xi meet to discuss climate change.

 Here is a link to the issue: 

 

https://www.bu.edu/cas/the-big-question-what-is-the-greatest-threat-to-human-health-from-climate-change/ 

 

In Search of Thoreau’s Flowers: A New Exhibit at Harvard about Thoreau and Climate Change

 By Richard B. Primack   

“The news that we hear, for the most part, is not news to our genius. It is the stalest repetition.”  

-Henry David Thoreau in “Life without Principle” 

A new exhibit at the Museum of Natural History at Harvard University, entitled “In Search of Thoreau’s Flowers” features our research using the records of Henry David Thoreau to study the effects of climate change. For the past 20 years, students and colleagues associated with our group have been carrying out fieldwork, analyzing data, and publishing papers on this topic.

Abe Miller-Rushing and Richard Primack at the exhibit 

The exhibit is a collaboration between scientists and artists to make the climate change message more accessible to the general public.

Henry David Thoreau made detailed flowering time observations during the 1850s, which we repeated over the past 20 years

The exhibit emphasizes how species in Concord are changing in their flowering times and their abundances over the past 170 years. Species which are most able to adjust their flowering times in response to a warming climate are able to persist in landscape.

Responsive species tend to persist in the face of climate change. Species not able to adjust, tend to decline.

Non-responsive species tend to decline.

Here is a link to the exhibit: 

https://hmnh.harvard.edu/search-thoreau-flowers 

Here is a link to a summary of our research on climate change in Concord: 

Ellwood, E.R., Gallinat, A.S., McDonough MacKenzie, C., Miller, T., Miller-Rushing, A.J., Polgar, C., and Primack, R.B. (2022). Plant and bird phenology and plant occurrence from 1851 to 2020 (non-Continuous) in Thoreau’s Concord, Massachusetts. Ecology 103, e3646. Link, PDF