The extraordinary beauty, rich geological history and challenges for preservation of the Vineyard landscape were all topics for discussion last Wednesday evening in paleoecologist David Foster’s guest lecture at the Polly Hill Arboretum in West Tisbury.
Mr. Foster is director of the Harvard Forest, an observation forest and ecological research center for scientists and students established in 1907. About 15 years ago, the forest initiated the Coastal Region Project to learn about the vast and geologically distinct coastal region from Long Island to Cape Cod and the two Islands.
Why focus on the Vineyard? In addition to a self-confessed personal interest, Mr. Foster said: “I think because the Vineyard brings together all the different pieces . . . the range of geology . . . and the ecological challenges. Also, [there is] a phenomenal array of conservation organizations. The wide range of conservation agencies are better managed and coordinated in an overall protection scheme.”
But as he delved deeper into the subject, the complexity of it all quickly became apparent. “How do we maintain the very majestic open lands on Martha’s Vineyard?” he asked the audience at the outset.
“Examining history and past techniques can help. We try to look at a landscape based on recent past and distant past. Landscapes and processes are always dynamic, [yet], they are dynamic at different rates.”
He discussed climate change and its direct effect on the landscape.
Oak trees, he explained, had died while beech trees survived. “How does nature respond to a catastrophic sweep of mortality, taking note of the mortality of oaks? There are pockets of beautiful beech thriving,” he said.
Expanding on the example with reference to another species — hemlocks — he explained that 5,000 years ago there was a hemlock decline. They then gradually recovered over time.
He showed the audience a curve chart labeled “Abrupt Dynamics with Climate Change and Disturbance” to demonstrate the oak population decline in Falmouth. He said he and his team gathered research from lake sediments.
He also discussed another natural factor that affects the landscape: hurricanes. He described the big storm of 1635 as a “cataclysmic event . . . the most powerful hurricane to ever hit Martha’s Vineyard.” He said the storm had the same path as Hurricane Bob, a relatively weak hurricane that hit the Island in 1991 but caused major tree damage.
He told the story of the Old Grove Forest in central New England, which was 300 years old and blew down in the hurricane of 1938. Mr. Foster said there is evidence that hurricanes have had a major impact on forest growth over the centuries.
He also discussed people and their relationship with the land. He said archeological research shows that during the Late Archaic period, before European settlers had arrived, oak and beech trees were thriving. Mr. Foster sand his team looked at pollen, “analyzing the way it has changed over time . . .” He added: “Native American behavior and the impact is pervasive throughout the land,” revealed directly and indirectly by use of fire.
“We can take history and use it to guide some of our practices . . . [but] elements of the past we will never be able to reproduce,” he said.
He noted that as the human population increased, so did deforestation, a direct result of clearing the land. The remarkable part is “people have dissociated themselves from the landscape,” and yet “forests come back.”
Wildlife, insects and farm animals, and their impact on the landscape were all part of the discussion.
So how can we manage the land? Through both active agriculture and native management, Mr. Foster said. He emphasized the need maintain habitats and praised the recent return to older techniques, such as sheep-tending, to keep fields open.
What’s the next step in his research? “Studying some of the things that are currently being done, tying it together with this beech piece . . . I want to tie it all back together into a book that makes it accessible,” he said.