Fall foliage season is a calendar highlight in states from Maine south to Georgia and west to the Rocky Mountains. It’s especially important in the Northeast, where fall colors attract an estimated US$8 billion in tourism revenues to New England every year.
As a forestry scientist, I’m often asked how climate change is affecting fall foliage displays. What’s clearest so far is that color changes are occurring later in the season. And the persistence of very warm, wet weather in 2021 is reducing color displays in the Northeast and mid-Atlantic. But climate change isn’t the only factor at work, and in some areas, human decisions about forest management are the biggest influences.
Longer growing seasons
Climate change is clearly making the Northeast warmer and wetter. Since 1980, average temperatures in the Northeast have increased by 0.66 degrees Fahrenheit (0.37 Celsius), and average annual precipitation has increased by 3.4 inches (8.6 centimeters) – about 8%. This increase in precipitation fuels tree growth and tends to offset stress on the trees from rising temperatures. In the West, which is becoming both warmer and drier, climate change is having greater physiological effects on trees.
My research in tree physiology and dendrochronology – dating and interpreting past events based on trees’ growth rings – shows that in general, trees in the eastern U.S. have fared quite well in a changing climate. That’s not surprising given the subtle variations in climate across much of the eastern U.S. Temperature often limits trees’ growth in cool and cold regions, so the trees usually benefit from slight warming.
In addition, carbon dioxide – the dominant greenhouse gas warming Earth’s climate – is also the molecule that fuels photosynthesis in plants. As carbon dioxide concentrations in the atmosphere increase, plants carry out more photosynthesis and grow more.
More carbon dioxide is not automatically good for the planet – an idea often referred to as “global greening.” There are natural limits to how much photosynthesis plants can carry out. Plants need water and nutrients to grow, and supplies of these inputs are limited. And as carbon dioxide concentrations rise, plants’ ability to use it decreases – an effect known as carbon dioxide saturation.
For now, however, climate change has extended the growing season for trees in the Northeast by about 10-14 days. In my tree ring research, we routinely see trees putting on much more diameter growth now than in the past.
This effect is particularly evident in young trees, but we see it in old trees as well. That’s remarkable because old trees’ growth should be slowing down, not speeding up. Scientists in western states have even noted this acceleration in bristlecone pines that are over 4,000 years old – the oldest trees in the world.
Fall colors emerge when the growing season ends and trees stop photosynthesizing. The trees stop producing chlorophyll, the green pigment in their leaves, which absorbs energy from sunlight. This allows carotenoid (orange) and xanthophyll (yellow) pigments in the leaves to emerge. The leaves also produce a third pigment, anthocyanin, which creates red colors. A longer growing season may mean that fall colors emerge later – and it can also make those colors duller.
A changing mix of trees
Climate isn’t the only thing that affects fall colors. The types of tree species in a forest are an even bigger factor, and forest composition in the eastern U.S. has changed dramatically over the past century.
Notably, eastern forests today have more species such as red maple, black birch, tulip poplar and blackgum than they did in the early 20th century. These trees are shade-tolerant and typically grow in conditions that are neither extremely wet nor extremely dry. They also produce intense red and yellow displays in the fall.
This shift began in the 1930s, when federal agencies adopted policies that called for suppressing all wildfires quickly rather than letting some burn. At that time, much of the eastern U.S. was dominated by fire-adapted oak, pine and hickory. Without fires recurring once or twice a decade, these species fail to regenerate and ultimately decline, allowing more shade-tolerant, fire-sensitive trees like red maple to invade.
There is evidence that some tree species in the eastern U.S. are migrating to the north and west because of warming, increasing precipitation and fire suppression. This trend could affect fall colors as regions gain or lose particular species. In particular, studies indicate that the range of sugar maples – one of the best color-producing trees – is shifting northward into Canada.
Intensive logging and forest clearance across the eastern U.S. through the mid-1800s altered forests’ mix of tree species.
Forests under pressure
So far it’s clear that warming has caused a delay in peak colors for much of the East, ranging from a few days in Pennsylvania to as much as two weeks in New England. It’s not yet known whether this delay is making fall colors less intense or shorter-lasting.
But I’ve observed over the past 35 years that when very warm and wet weather extends into mid- and late October, leaves typically go from green to either dull colors or directly to brown, particularly if there is a sudden frost. This year there are few intense red leaves, which suggests that warmth has interfered with anthocyanin production. Some classic red producers, such as red maple and scarlet oak, are producing yellow leaves.
Other factors could also stress eastern forests. Climate scientists project that global warming will make tropical storms and hurricanes more intense and destructive, with higher rainfall rates. These storms could knock down trees, blow leaves off those left standing and reduce fall coloration.
Maple leaves infected with a fungal pathogen that can lead to premature leaf loss.UMass Amherst, CC BY-ND
Forests shade the earth and absorb carbon dioxide. I am proud to see an increasing number of foresters getting involved in ecological forestry, an approach that focuses on ecosystem services that forests provide, such as storing carbon, filtering water and sheltering wildlife.
Foresters can help to slow climate change by revegetating open land, increasing forests’ biodiversity and using highly adaptable tree species that are long-lived, produce many seeds and migrate over time. Shaping eastern forests to thrive in a changing climate can help preserve their benefits – including fall color displays – well into the future.
by Henry Geddes and Martin Valdiviezo / translated by Angélica Almazán / Intercontinental Cry
Long before it was used by early European settlers to establish the Massachusetts Bay Company–and later, the Massachusetts Bay Colony–the term “Massachusetts” referred to an Algonquian-speaking nation known as the Massachuset. One of dozens of smaller nations that made up the Wampanoag Nation, the Massachuset lived in what is now the eastern side of the Commonwealth of Massachusetts, a region that includes the City of Boston. The name “Massachuset” means “At or about the great hill” in the Algonquian language.
The Massachuset’s territory was home to numerous hills and stone structures that lent themselves to burial mounds, ceremonial sites and other religious practices. While many of these sites were undoubtedly lost to the ravages of colonialism, the legacy of the Massachuset invariably remains in the land itself. And so too that of other indigenous nations inhabiting the surrounding area.
Massachusetts–the U.S. state–is home to another legacy. It is the site of the first wave of European colonization that resulted in the decimation of First Nations in North America. While the Massachuset disappeared by 1800, the Mohegan, the Mohican and the greater Wampanoag Nation endured. Efforts such as the modern tradition of “Thanksgiving” have nevertheless obscured the violent nature of the encounter. Even now, Indigenous Peoples continue to struggle for their territorial and cultural rights across the breadth of the U.S. landscape, as the Sioux at Standing Rock can attest in their struggle against the oil pipeline project in North Dakota.
There is another chapter of this struggle currently playing out in the Western Massachusetts town of Shutesbury. Lake Street Development Partners LLC wants to build a 6-megawatt power plant, euphemistically labelled as the Wheelock Tract ‘Solar Farm’ Project to veil an otherwise ecologically disastrous initiative to clear 28.6 acres of healthy forest where the Mohican Peoples claim to have cemeteries and other ceremonial sites.
The Shutesbury Planning Board approved this project in June 2016 even though members of the Narragansett and Wampanoag tribes had previously expressed their concern for an enterprise that would potentially undermine their cultural property rights.
Currently, the project has been stopped by a court order initiated by an individual of Mohawk ancestry to start an investigation that allows Narragansett and Wampanoag representatives with relevant expertise in identifying indigenous cultural property to confirm the existence of archaeological sites on the land in question.
The developers, Lake Street Corporation and the owners of the W.D. Cowls land, have so far refused to give indigenous representatives access to the location to confirm (or not) the presence of indigenous cultural property. The developers intend to enforce an archaeological report conducted by SWCA, an environmental consulting firm from Arizona. According to SWCA’s report, there are no ceremonial sites in the region.
The research that led to the report sparked controversy because of its lack of cultural and geographic context that might have been provided by qualified indigenous experts on local native cultures, a critique made by external reviewers that included several high profile archaeologists. The debate on the existence of indigenous archaeological remains is crucial to determine the legal foundations and the political instruments that can sustain the cultural property rights of First Nations in Massachusetts and beyond.
Besides the threat to the cultural property rights of the Mohican People, as well as the affront to biodiversity and carbon sequestration involved in clearing almost 30 acres of forest, preliminary research results in Great Britain and the U.S.regarding the actual ecological impact of industrial-scale solar arrays errs on the side of caution until the research is more conclusive.
Numerous oil and hydroelectric projects are ongoing causes for conflicts between energy corporations, Indigenous Peoples and environmental groups, since they involve the destruction or expropriation of ancestral remains and territories. Allegedly, the development of alternative energy projects (such as solar power) could reconcile the interests of these three parties. However, this case shows that solar power projects can have negative social and environmental consequences when designed to privilege capitalist and colonial private interests.
It is important to observe that this debate on the Shutesbury indigenous archaeological heritage is taking place in a context of huge structural inequalities marked by the long-term disregard for indigenous treaties and rights, one that has denigrated indigenous cultures and even denied that they still exist in states like Massachusetts. Such cultural subjugation is still being massively practiced through the statements of public officials and the Media, as well as in books, movies and educational programs that make Indigenous Peoples and their cultural heritage invisible. This is a manifestation of the political marginalization of Indigenous Peoples in Massachusetts that facilitates the appropriation of their legacy. Nevertheless, the recognition of the indigenous cultures in the U.S. and in the world is a fundamental topic of human rights, and it is crucial for the establishment of fair and inclusive democratic societies.
A common thread in the situation of our indigenous brothers in Anglo America and Latin America, from Canada to Chile, is the need to fight against the Eurocentric order to ensure their universal rights to territory, as well as respect for their cultural properties and rights to a dignified and peaceful life. To a greater or lesser extent, despite their democratic and sometimes multicultural or intercultural constitutions, these States continue to reproduce the colonial legacy. The decolonization of the Americas is as crucial for the recognition of our Indigenous Peoples as it is for the fulfillment of the democratic ideals of freedom, equality and solidarity within each one of its States. The stones on the great hills of Massachusetts do matter as sacred spaces and ceremonial sites for all Americans.
Henry Geddes: Associated Professor, Communication Department, University of Massachusetts-Amherst
Martín Valdiviezo: Postdoctoral Researcher. Communication Department, University of Massachusetts-Amherst, Assistant Professor. Education Department. Pontificia Universidad Católica del Perú
A 93-year-old anti-nuclear activist was among more than 130 protesters arrested at the corporate headquarters of the Vermont Yankee nuclear power plant on the first day of the plant’s operation after the expiration of its 40-year license.
Frances Crowe, of Northampton, Mass., said she wants Vermont Yankee to cease operations because she feels it’s a threat to the people who live nearby.
“As I was walking down, all I could think of was Fukushima and the suffering of all the people, and I don’t want that to happen to New England,” Crowe said, referring to the Japanese nuclear reactor damaged last year after an earthquake and tsunami.
When asked how many times she’d been arrested, she answered: “Not enough.”
A heavy police presence and ropes blocked off access to the offices in Brattleboro during Thursday’s protest. The arrests were made calmly and without any confrontation, with obvious signs that protesters and police had worked out the logistics beforehand.
Brattleboro Police Chief Gene Wrinn said in a statement that more than 130 people had been arrested for unlawful trespass. He said after being processed, they were later released.
